<!-- image -->

Review                                                                                                                                                   Open Access

## Diagnosing Borderline Personality Disorder During Adolescence: A Review of the Published Literature

Andrea Fossati

Department of Humanities, Libera Università Maria Ss. Assunta, Rome, Italy and San Raffaele Hospital, Milano, Italy

Corresponding author:

fossati.andrea@hsr.it

## Abstract

Borderline  personality  disorder  (BPD)  is  a  debilitating  disorder  that  occurs  in  approximately  1%  to  3%  of  the  general population. BPD is not only relatively prevalent; it is also associated with significant public health and security concerns. The clinical and social burden of adult BPD diagnosis has resulted in the desire for early diagnosis and the implementation of early intervention programs. A qualitative review of the scientific literature suggested that adolescence is a critical point for  the  early  identification  and  therapeutic  treatment  of  BPD.  Although  findings  are  far  from  conclusive,  the  inter-rater reliability and internal consistency of the Diagnostic and Statistical Manual of Mental Disorders symptom criteria for BPD during adolescence  seem  adequate.  Recent  studies  based  on  a  rigorous  methodology  of  BPD  assessment  and  large  community samples reported prevalence rates for BPD diagnosis during adolescence that were less suspect than previous findings. A number of research studies addressed the construct validity of BPD in adolescents (i.e., whether a BPD diagnosis during adolescence  actually  measures  what  is  intending  to  measure)  and  reported  consistent  relationships  between  BPD  and associated areas of dysfunction and distress as evidence of the validity of the BPD diagnosis. Research evidence indicates that there is no single symptom that is predictive of later BPD diagnosis during adolescence; rather, a pattern of two to three selected  BPD  symptoms  that  are  evident  during  adolescence  seemed  to  be  highly  predictive  of  later  BPD  diagnosis, particularly when measures that were specifically designed to assess for BPD during adolescence were used as part of the assessment process.

Keywords:

borderline personality disorder; diagnosis; adolescence

Borderline personality disorder (BPD) is a debilitating  disorder  that  occurs  in  approximately 1%  to  3%  of  the  general  population  (1,2).  It  is characterized by distressful, impairing, and pervasive  dysregulation  of  the  following:  1)  affect (chronic  fear  of  abandonment,  affective  instability, intense  and  inappropriate  anger);  2)  self-concept and attention (dissociative experience); of cognition (distorted thoughts and perceptions); 3) interpersonal relationships (intense, volatile); and 4) behavior (impulsivity and repetitive  self-destructive behaviors)  (1).  Individuals  with  BPD  often  engage in  self-injurious  and  suicidal  behavior,  gambling, compulsive  shopping,  substance  or  alcohol  use, binge eating,  and  reckless  driving  (1,3).  Given  that these  types  of  impulsive,  self-destructive  behaviors may lead to psychiatric hospitalization, incarceration, or both the rate of BPD in psychiatric settings is  approximately  20%,  and  the  rate  in incarceration settings is even higher (1).

The  clinical  and  social  burden  of  adult  BPD diagnosis has resulted in the desire for early diagnosis and the implementation of early intervention  programs  (4-6),  which  may  promote more  adaptive  developmental  pathways  and  avert many of the outcomes that were briefly summarized previously.  During  the  last  three  decades,  several clinicians and researchers started to raise doubts as to  whether  it  is  plausible  to  suggest  that  BPD 'jumps out  of  the  blue'  in  a  person  as  he  or  she turns 18 (6-11). Indeed, adolescents with poor social and  academic  functioning  are  frequently  described as showing a constellation of symptoms of emotion dysregulation, instability of self-image and interpersonal relationships, and impulsivity that can be hardly differentiated from the clinical picture that would  suggest  a  BPD  diagnosis  in  adults  (8,12). Moreover,  the  array  and  complexity  of  symptoms associated with BPD  have inspired numerous etiological  hypotheses  regarding  the  developmental antecedents of BPD, including deprivation of early socialization, constant exposure to chaotic and traumatic environments, deviant family interactional patterns, and relatively subtle forms  of  neuropsychological and biochemical impairment (1). These  hypothetical  developmental  antecedents  are thought  to  lead  to  maladaptive  behaviors  during adolescence  or  even  during  childhood,  which  in turn are thought to be predictive of  a  BPD diagnosis in adulthood.

Notwithstanding these considerations, applying a diagnosis of BPD (or of any personality disorder) to adolescents  is  still  a  controversial  topic  (5).  The Diagnostic  and  Statistical  Manual  of  Mental  Disorders, Fifth  Edition (DSM-5)  Section  II  definition  permits the diagnosis of BPD in adolescents (3); however, it does remain vague, leaving much to clinical judgment  (5).  At  the  same  time,  adolescence  may not represent a smooth transition to adulthood for many  youngsters, and the transformations that physiologically  take  place  during  adolescence  may cause  difficulties  for  adolescents  and  their  families (8). Indeed, adolescence is usually considered to be a developmental stage that is characterized by impulsivity,  emotional  and  psychological  turmoil, rapid  mood  swings,  and  increased  vulnerability  to breakdowns  in  adaptive  behaviors  (13,14).  It  is important that adaptive adolescence turmoil not be misdiagnosed as emerging BPD.

Given the stability and potential clinical implications of personality pathology in adolescents, it  is  important to examine whether BPD diagnoses can  be  reliably  and  validly  diagnosed  in  this  age group. All available data indicate that adolescence is a critical period in the early identification  and therapeutic treatment of BPD. The study of BPD in adolescence could take advantage of an overview of current knowledge about this topic to evaluate the applicability of the BPD diagnosis to adolescents, to identify  available  instruments  for  detecting  BPD characteristics during adolescence, and to plan evidence-based practices that are aimed at preventing  the  development  of  full-blown  BPD pathology.

With  these  considerations  in  mind,  a  qualitative review  of  the  published  scientific  literature  was carried out to answer the following questions: 1) Is it possible to reliably diagnose BPD during adolescence? 2) If so, is there any evidence for the construct validity of BPD diagnosis during adolescence? 3) Is it possible to identify early

'warning signs' of emerging BPD during adolescence? And are there any measures that were specifically designed to yield reliable and valid BPD diagnoses during adolescence?

## Method

A  search  for  studies  dealing  with  BPD  during adolescence  was  conducted  via  the  PsychInfo  and Scopus bibliographic databases. The following terms were used: 'borderline personality disorder,' 'BPD,'  'borderline,'  'adolescence,'  and  'teen.' The  search  included  all  fields  in  the  PsychInfo database and the title, abstract, and keywords in the Scopus  database.  Existing  reviews  were  used  as additional sources of information (5;15-17). Studies of any design that focused on BPD during adolescence  were  screened.  To  be  included  in  this study, articles had to be written in English, and they had  to  include  child,  adolescent,  and  young  adult samples.  Of  the  articles  identified,  only  those  that specifically discussed the validity, reliability, stability, and  assessment  of  BPD  in  adolescents  and  those that compared adolescents with BPD to adults with BPD were retained for the review.

## Results

Table  1  presents  an  overview  of  the  main  studies included in this review.

The  reliability  of  borderline  personality  disorder  diagnosis during adolescence

When  semi-structured interviews were used to assess  DSM  symptom  criteria  during  adolescence, empirical studies consistently reported adequate inter-rater reliability values for BPD  diagnosis, which were usually in the range of .85 to .88 range (18-20).  The  Childhood  Interview  for  DSM-IV Borderline Personality Disorder (CI-BPD) represents  the  only  current  published  interviewbased measure specifically adapted for use in children and adolescents (21). Zanarini and colleagues (22) used it in a sample of 6410 11-yearold  children  in  the  United  Kingdom.  Inter-rater reliability  with  the  use  of  taped  interviews  of  30 children revealed κ values that ranged from 0.36 to 1.0,  with  a  median  value  of  0.88.  Overall,  86%  of the κ values  were  in  the  excellent  range  of  more than  0.75,  and  two  independent  studies  reported similar findings (23,24). Recently, Sharp and colleagues (25) showed that, with the use of the CIBPD, the inter-rater reliability of the DSM-IV BPD diagnosis in adolescents was excellent, with a Cohen's κ value  of  0.89.  Although  findings  are  far from  conclusive,  the  internal  consistency  of  the DSM symptom criteria for BPD during adolescence ADHD, Attention-deficit/hyperactivity disorder; BPD, borderline personality disorder; BPFS, Borderline Personality Features Scale; BPFSC, BPFS for Children; BPFSP, BPFS for Parents; BPQ, Borderline Personality Questionnaire; CI-BPD, Child Interview for DSM-IV Borderline Personality Disorder; DSM, Diagnostic and Statistical Manual of Mental Disorders; IRT, item response theory; MSI-BPD, McLean Screening Instrument for Borderline Personality Disorder; ODD, oppositional defiant disorder; SCID-II, Structured Clinical Interview for DSM Axis II Disorders.

TABLE 1. Overview of the Main Studies included in the Review

| Authors                                                       | Population                                                                                                               | Description                                                                                                                                                                                                                                                                                           | Results                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|---------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Korenblum, Marton, Golombek& Stein; 1990                      | Nonclinical sample of urban 18 year olds                                                                                 | Forty-two percent of a nonclinical sample of urban 18 year olds displayed some degree of personality dysfunction.                                                                                                                                                                                     | Teenagers who initially presented as avoidant, dependent, compulsive, or passive-aggressive seemed to grow out of their dysfunction. Most of the adolescents who were identified as antisocial during early or middle adolescence migrated into the histrionic, narcissistic, borderline cluster during late adolescence.                                                                                                                                                                                                                                                                                    |
| Kutcher, Marton& Korenblum; 1990                              | 20 euthymic bipolar teens                                                                                                | Twenty euthymic bipolar teens were assessed with the use of the Personality Disorders Examination.                                                                                                                                                                                                    | Thirty-five percent met DSM-III-R criteria for at least one personality disorder. Three of the 20 (15%) had a BPD diagnosis.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| Ludolph, Westen, Misle et al; 1990                            | 50 females psychiatrically hospitalized at a major medical center                                                        | Twenty-seven female inpatients between the ages of 14 and 18 years were compared with 23 non-BPD, age-matched female inpatient controls on retrospectively assessed variables that measured psychological, familial, and constitutional factors.                                                      | Results support the notion that a chaotic or traumatic early environment can support the development of BPD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| Bernstein, Cohen, Velez, Schwab-Stone, Siever& Shinsato; 1993 | A randomly selected community sample of 733 youths ranging in age from 9 to 19 years and followed for a 2-year period    | The protocol consisted of structured interviews with the adolescents and their mothers as well as self-report questionnaires.                                                                                                                                                                         | The overall prevalence of personality disorders peaked at age 12 in boys and at age 13 in girls; it declined thereafter. Obsessive-compulsive personality disorder was the most prevalent moderate Axis II disorder, narcissistic personality disorder was the most prevalent severe disorder, and schizotypal personality disorder was the least prevalent Axis II disorder. Longitudinal follow up revealed that, although most Axis II disorders did not persist over a 2-year period, subjects with disorders identified earlier remained at elevated risk for receiving a diagnosis again at follow up. |
| Garnet, Levy, Mattanah, Edell& McGlashan; 1994                | 21 adolescent inpatients with BPD were contacted 2 years after the index hospitalization                                 | Diagnostic criteria that are relatively specific to BPD were identified in severely ill adolescent inpatients in the attempt of predicting stable BPD symptoms during this turbulent time.                                                                                                            | Seven of these patients met the criteria for BPD at follow up. These criteria were sensitive for the stable disorder but not very specific.                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| Mattanah, Becker, Levy, Edell& McGlashan; 1995                | 70 hospitalized adolescents followed up 2 years after hospitalization                                                    | The stability of DSM-III-R disorders and groups of disorders in adolescent inpatients were examined. Adolescents were reliably assessed with the use of structured diagnostic interviews for DSM-III-R disorders. Two years later, the subjects were independently assessed with the same interviews. | Diagnostic stability in these hospitalized adolescents was less than that reported for adults. Personality disorder clusters were relatively unstable, especially those from Clusters A and C.                                                                                                                                                                                                                                                                                                                                                                                                               |
| Pinto, Grapentine, Francis& Picariello; 1996                  | 19 depressed female adolescents with BPD were compared with 21 depressed inpatients without BPD                          | The affective and cognitive features of BPD in adolescence were systemically examined with the use of standardized measures of these constructs while controlling for depression.                                                                                                                     | Both BPD and non-BPD adolescents endorsed significantly elevated levels of self-reported depression, anger, anxiety, hopelessness, self-deprecatory attributional style, and external locus of control. Adolescents with BPD endorsed significantly poorer self-concepts as compared with their non-BPD peers; this difference was not an artifact of depressive severity.                                                                                                                                                                                                                                   |
| Meijer, Goedhart& Treffers; 1998                              | Hospitalized adolescents with ( n = 14) and without ( n = 22) BPD, according to the Diagnostic Interview for Borderlines | A follow-up study was conducted to determine the persistence of BPD and of separate BPD symptoms in adolescents.                                                                                                                                                                                      | Of the 14 adolescents with BPD, only 2 were again classified as having BPD after 3 years, but some of the separate BPD symptoms were still present. In the non-BPD group, no new cases were found after 3 years.                                                                                                                                                                                                                                                                                                                                                                                             |
| Becker, Grilo, Morey, Walker, Edell& McGlashan; 1999          | 38 adolescents and 28 adults assessed with the Personality Disorder Examination                                          | The authors examined the applicability of personality disorder criteria to adolescent inpatients by evaluating internal consistency and criterion overlap.                                                                                                                                            | Internal consistency appeared to be lower in adolescents, with the largest differences being identified for most Cluster B disorders. Intercategory analysis indicated that criterion overlap may be greater among adolescents.                                                                                                                                                                                                                                                                                                                                                                              |

| Authors                                               | Population                                                                                                                                                                                                       | Description                                                                                                                                                                                                                                                                                                         | Results                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Levy et, Becker, Grilo et al; 1999                    | 165 hospitalized adolescents assessed with a structured interview for personality disorder diagnoses; 2 years after initial assessment, 101 subjects were independently reassessed with the same measures        | The authors investigated the concurrent and predictive validity of the DSM- III-R diagnosis of personality disorder in adolescents by means of baseline and follow-up assessments of inpatients treated at the Yale Psychiatric Institute.                                                                          | At baseline, adolescents with personality disorders were significantly more impaired than those without personality disorders. At follow up, adolescents with a personality disorder diagnosis at baseline had used significantly more drugs and had required more inpatient treatment during the follow-up interval. Over time, the scores on the Global Assessment of Functioning Scale and the Symptom Checklist-90-Revised of adolescents who had been diagnosed with personality disorders at baseline became more similar to the scores of adolescents without personality disorders. |
| Becker, Grilo, Edell& McGlashan; 2000                 | 138 adolescents and 117 adults were reliably assessed with the Personality Disorder Examination                                                                                                                  | The authors examined the comorbidity of BPD with other personality disorders in a series of consecutively admitted adolescents. For comparison, the comorbidity of BPD with other personality disorders was also examined in a series of adults consecutively admitted to the same hospital during the same period. | Sixty-eight adolescents and 50 adults met the diagnostic criteria for BPD. For the adults, significant diagnostic co-occurrence with BPD was observed for antisocial personality disorder only. For the adolescents, BPD showed significant co-occurrence with schizotypal and passive-aggressive personality disorders.                                                                                                                                                                                                                                                                    |
| Chabrol, Montovany, Chouicha, Callahan& Mullet; 2001  | A random sample of 1363 high school students completed the Screening Test for Comorbid Personality Disorders; 107 of them volunteered to be interviewed                                                          | The authors estimated the frequency of BPD in French high school students.                                                                                                                                                                                                                                          | This study found a high frequency of BPD among French adolescents. The authors estimated the overall frequency of BPD to be 10% for boys and 18% for girls. After a peak of frequency at the age of 14 years for both sexes, the frequency increased significantly again during late adolescence.                                                                                                                                                                                                                                                                                           |
| Crawford, Cohen& Brook; 2001                          | A community sample of 407 adolescents                                                                                                                                                                            | This study examined the relationship over time between Cluster B personality disorder symptoms and comorbid internalizing and externalizing symptoms                                                                                                                                                                | Internalizing and externalizing symptoms each predicted subsequent Cluster B symptoms in girls, although these effects occurred only at specific developmental stages. Cluster B symptoms in boys and girls at the ages 10 to 14 years predicted externalizing symptoms 2 years later.                                                                                                                                                                                                                                                                                                      |
| Grilo, Becker, Edell& McGlashan; 2001                 | 60 adolescent inpatients assessed with the Personality Disorder Examination soon after admission to the Yale Psychiatric Institute and independently reassessed with the same instrument 2 years after discharge | The authors examined the stability of DSM-III-R personality disorder dimensions in a clinical sample of adolescents.                                                                                                                                                                                                | As compared with baseline, dimensional scores for most personality disorders were significantly lower at follow up; none were significantly higher. Low to moderate stability for dimensional measures of personality dysfunction in adolescents was observed.                                                                                                                                                                                                                                                                                                                              |
| Becker, Grilo, Edel, & McGlashan; 2002                | 123 adolescents and 106 adults assessed with the Personality Disorder Examination                                                                                                                                | The authors examined the diagnostic efficiency of BPD criteria in adolescent inpatients. For comparison, the diagnostic efficiency of BPD criteria was also examined in a group of concurrently recruited adult inpatients.                                                                                         | Sixty-five adolescents and 50 adults met the diagnostic criteria for BPD. There were no significant differences between groups with regard to base rates of BPD diagnosis or for any BPD criteria. The best inclusion criterion for the adolescents was abandonment fears, although for the adults all symptoms were approximately equivalent in this regard. The most efficient exclusion criterion was uncontrolled anger for the adolescents and impulsiveness for the adults.                                                                                                           |
| Chabrol, Montovany, Callahan, Chouicha& Ducongé; 2002 | A non-patient sample of 118 adolescents                                                                                                                                                                          | The goal of this study was to examine the factor structure of the Revised Diagnostic Interview for Borderlines                                                                                                                                                                                                      | A principal components factor analysis with a Varimax rotation extracted three factors. A confirmatory factor analysis showed that this three-factor model provided an adequate fit. There may be homogeneous components of BPD symptomatology in adolescents that may reflect affective disturbances and defensive mechanisms.                                                                                                                                                                                                                                                             |

| Authors                                                                | Population                                                                                                                                           | Description                                                                                                                                                                                                                                                                                                                                                                                 | Results                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Chanen, Jackson, McGorry, Allot, Carkson & Yuen; 2004                  | 101 participants who were 15 to 18 years old were assessed with the use of the SCID-II at baseline; 97 were re-interviewed face-to- face at 2 years  | The 2-year stability of categorical and dimensional personality disorder in an older adolescent psychiatric outpatient sample was examined.                                                                                                                                                                                                                                                 | Of the participants with a categorical personality disorder diagnosis at baseline, 74% still met criteria for a personality disorder at follow up, with marked gender differences (83% of females and 56% of males). However, categorical personality disorder endured in 100% of those who received inpatient care. The study supports that, in late teenage outpatients, the 2- year stability of the global category of personality disorder is high, and the stability of dimensionally rated personality disorder appears to be similar to that found among young adults.                                                                                                                |
| Bondurant, Greenfield &Tse; 2004                                       | 36 publications                                                                                                                                      | Relevant publications were reviewed.                                                                                                                                                                                                                                                                                                                                                        | The construct validity of adolescent BPD is supported by internal consistency, group differences, convergent validity, and concurrent validity. By contrast, the adolescent BPD criteria manifested less construct validity than the adult diagnosis in that the criteria did not uniformly predict the overall diagnosis; there was more criterion overlap with other personality disorders and a broader pattern of Axis II comorbidity. Further diminishing the construct validity is the fact that factor analysis suggested that adolescent BPD was not a single entity. Its low predictive validity was demonstrated by little diagnostic stability through adolescence into adulthood. |
| Crick, Murray-Close& Woods; 2005                                       | A normative sample of 400 (54% female) fourth though sixth graders who were assessed during the Fall of Year 1, Spring of Year 1, and Fall of Year 2 | The goals of this study were as follows: the development of a psychometrically sound self-report instrument that assesses BPD during childhood, the BPFSC; the examination of the stability of BPD features during childhood; the evaluation of gender differences in BPD features during childhood; and the evaluation of the specificity of the BPFSC for the assessment of BPD features. | The use of linear mixed modeling techniques provided evidence for the construct validity of the BPFSC. BPD features as assessed with the BPFSC were found to be moderately stable over the course of the study, with girls reporting higher levels of BPD features than boys. Results also demonstrated that children's scores on the BPFSC were uniquely related to indicators of BPD pathology above and beyond their scores on the Children's Depression Inventory.                                                                                                                                                                                                                        |
| Becker, McGlashan& Grilo; 2006                                         | 123 adolescent inpatients assessed with structured diagnostic interviews for DSM-III- R Axis I and II disorders                                      | The authors examined the factor structure of BPD in hospitalized adolescents, and they also sought to add to the theoretical and clinical understanding of any homogeneous components by determining whether they may be related to specific forms of Axis I pathology.                                                                                                                     | Exploratory factor analysis of BPD criteria in adolescent inpatients revealed four BPD factors that appear to differ from those reported for similar studies of adults. The factors represent components of self-negation, irritability, poorly modulated relationships, and impulsivity.                                                                                                                                                                                                                                                                                                                                                                                                     |
| Chabrol& Leichsenring; 2006                                            | A nonclinical sample of 243 adolescents                                                                                                              | The aim of this study was to explore the relationship of the structural criteria of BPD organization (as assessed by the French version of the Borderline Personality Inventory) with psychopathic traits (as assessed by the French version of the Levenson Self-Report Psychopathy Scale).                                                                                                | Significant correlations were found between the Borderline Personality Inventory scales of identity diffusion, primitive defense mechanisms, impaired reality testing, and psychopathic traits of callousness and impulsivity, which suggests that BPD may contribute to psychopathic traits in non-forensic, non-clinical adolescents.                                                                                                                                                                                                                                                                                                                                                       |
| Nock, Joiner, Gordon, Lloyd-Richardson& Prinstein; 2006                | 89 inpatients who engaged in non-suicidal self-injury during the previous 12 months were clinically interviewed                                      | This study reported on the diagnostic correlates of adolescents with a recent history of non-suicidal self-injury and examined the relationship between non-suicidal self-injury and suicide attempts                                                                                                                                                                                       | Results revealed that 87.6% of adolescents who engaged in non-suicidal self- injury met the criteria for a DSM-IV Axis I diagnosis. Most adolescents assessed also met criteria for an Axis II personality disorder (67.3%). Overall, 70% of adolescents who engaged in non-suicidal self-injury reported a lifetime suicide attempt, and 55% reported multiple attempts.                                                                                                                                                                                                                                                                                                                     |
| Segal-Trivitz, Bloch, Goldburt, Sobol-Havia, Levkovitch& Ratzoni; 2006 | 20 adolescents and 20 adults                                                                                                                         | A retrospective chart review of 20 adolescent and 20 adult BPD patients was conducted to characterize adolescent BPD and compare it with adult BPD. The retrieved data included demographics, history features, symptoms, and observations made during hospitalizations and treatments.                                                                                                     | This study supported the general similarity of BPD between adolescents and adults. The differences included the number of report pages during hospitalization, current self-mutilation, past and present obsessive- compulsive symptoms, and past escapes. Adults had more alcohol abuse.                                                                                                                                                                                                                                                                                                                                                                                                     |

| Authors                                               | Population                                                                                                                                                                                                                             | Description                                                                                                                                                                                                                                                                                                                                                           | Results                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|-------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Chanen, Jovev, Djaja et al; 2008                      | 101 outpatient youth between the ages of 15 and 25 years                                                                                                                                                                               | This study compared the MSI-BPD, the BPQ, the BPD items from the International Personality Disorder Examination Screening Questionnaire, and the BPD items from the SCID-II Personality Questionnaire.                                                                                                                                                                | All four instruments performed similarly, but the BPQ had the best mix of characteristics, with moderate sensitivity, the highest specificity, a high negative predictive value, and a moderate positive predictive value. As compared with the other three instruments, the BPQ had the highest overall diagnostic accuracy, a substantially higher kappa with the criterion diagnosis, the highest test-retest reliability, and the highest internal consistency. The only clear difference to emerge in the receiver-operating characteristic curve analysis was that the BPQ significantly outperformed the MSI-BPD.                         |
| Miller, Flory, Miller, Harty, Newcorn& Halperin; 2008 | A longitudinal sample of 96 adolescents diagnosed with ADHD were compared with a matched control group of 85 adolescents who had never been diagnosed with ADHD                                                                        | This study examined the presence of personality disorders in a longitudinal sample of 96 adolescents who had been diagnosed with ADHD when they were 7 through 11 years old as compared with a matched control group of adolescents who had never been diagnosed with ADHD. Participants were between 16 and 26 years old at follow up.                               | Individuals diagnosed with ADHD during childhood are at increased risk for personality disorders during late adolescence (specifically borderline, antisocial, avoidant, and narcissistic personality disorders). Those with persistent ADHD were at higher risk for antisocial and paranoid personality disorders but not for other personality disorders when compared with those in whom ADHD had remitted.                                                                                                                                                                                                                                   |
| Miller, Muehlenkamp& Jacobson, 2008                   | Of the 205 articles identified, only those that specifically reported on the validity, reliability, and stability of BPD in adolescents and those that compared BPD in adolescents with BPD in adults were retained.                   | This article reviewed the empirical literature to evaluate the prevalence, reliability, and validity of a BPD diagnosis during adolescence.                                                                                                                                                                                                                           | It was concluded that the features of BPD diagnoses in adolescents are comparable with those found in adults. Furthermore, there appears to be a legitimate subgroup of adolescents for whom the diagnosis remains stable over time as well as a less severe subgroup that moves in and out of the diagnosis. Although caution is warranted, the formal assessment of BPD in adolescents may yield more accurate and effective treatment for adolescents who are experiencing BPD symptomatology.                                                                                                                                                |
| Winograd , Cohen& Chen; 2008                          | A randomly selected community cohort of adolescents from the Children in the Community Study; the retained sample was characteristic of the full sample ( N = 748; age range, 9 to 18 years in 1983 and 1984; 50% male and 50% female) | In this study, the relationship of early BPD symptoms to subsequent psychosocial functioning and attainment was investigated on the basis of data from the Children in the Community cohort.                                                                                                                                                                          | On average, participants with higher levels of early adolescent BPD symptoms scored consistently lower in role function, social function, and life satisfaction from mid adolescence through mid adulthood. BPD symptoms predicted lower academic and occupational attainment, less partner involvement, and fewer attained adult developmental milestones. Adolescent BPD symptoms were also associated with adult BPD symptoms, BPD diagnosis, general impairment, and the need for services at a mean age of 33 years. These effects were evident despite symptom decline with age, and they were independent of adolescent Axis I disorders. |
| Biskin, Paris, Renaud, Raz& Zelkowitz; 2011           | 47 adolescent girls assessed over a 10-year period                                                                                                                                                                                     | This study examined the outcomes of patients who were diagnosed with BPD before they were 18 years old.                                                                                                                                                                                                                                                               | Thirty-one participants had a prior diagnosis of BPD, whereas 16 had not met BPD criteria. At 4.3 years after initial presentation (mean age, 19.6 years), only 11 index patients still met criteria for BPD, and no new cases developed. Those who did not remit were significantly more likely to have a current episode of major depressive disorder, lifetime substance use disorder, and self-reported childhood sexual abuse.                                                                                                                                                                                                              |
| Chang, Sharp& Ha; 2011                                | An inpatient sample of adolescents ( n = 51) ranging in age from age 12 to 18 years completed the BPFS and were administered the CI-BPD by trained clinical research staff                                                             | The purpose of the study was to examine the criterion validity of the BPFSC by assessing the performance of the self-report and a newly developed parent report version of the measure (the BPFSP) for the detection of a BPD diagnosis in adolescent inpatients. This study also examined parent-child agreement and the internal consistency of the BPFS subscales. | The BPFSC demonstrated high accuracy with regard to identifying adolescents with diagnoses of BPD as measured by the CI-BPD, whereas the BPFSP had moderate accuracy. Parent-child agreement for the total scores was significant. Cronbach's alphas suggested internal consistency for the four subscales of the BPFS.                                                                                                                                                                                                                                                                                                                          |

| Authors                                                    | Population                                                                                                                                                                                                                                                 | Description                                                                                                                                                                                                                                                                                                                          | Results                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Sharp, Pane, Ha et al; 2011                                | 111 adolescent inpatients between the ages of 12 and 17 years                                                                                                                                                                                              | This study aimed to examine mentalizing in adolescents with emerging BPD from a dimensional and categorical point of view after controlling for gender, age, and Axis I and Axis II symptoms. It also aimed to explore the mediating role of emotion regulation in the relationship between theory of mind and BPD traits.           | The findings suggested a relationship between BPD traits and 'hypermentalizing' (i.e., excessive and inaccurate mentalizing) that was independent of age and gender as well as of externalizing, internalizing, and psychopathy symptoms. The relationship between hypermentalizing and BPD traits was partially mediated by difficulties with emotion regulation; this accounted for 43.5% of the hypermentalizing-to-BPD path.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| Sharp, Mosko, Chang& Ha; 2011                              | 171 community boys between the ages of 8 and 18 years completed the BPFSC and a self- report measure of Axis I psychopathology; parents completed a parent-report version of the BPFSC (the BPFSP) and a standard measure of Axis I psychopathology        | This study investigated the cross-informant concordance (i.e., youth self- report vs. parent-report) of the BPFSC; it also examined the concurrent validity of the BPFSC by showing that youth who had high scores on the BPFSC also demonstrated poor clinical and psychosocial functioning as measured by a standard Axis I scale. | Concurrent validity and modest parent-child concordance were demonstrated for the BPFSC. The BPFSC and BPFSP show promise as dimensional measures for the assessment of BPD features in boys. Youth with BPD features showed poorer clinical and psychosocial functioning in all domains, especially where externalizing problems were concerned.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Westen, Betan& Defife; 2011                                | A national random sample of 139 psychiatrists and clinical psychologists completed a battery of instruments with a randomly selected adolescent patient in their care                                                                                      | This study investigated the nature of identity disturbance in an adolescent clinical sample and explored its links with personality pathology, particularly BPD.                                                                                                                                                                     | Identity disturbance in adolescents is a clinically meaningful and multidimensional construct that exhibits significant relationships with different forms of severe personality pathology, most notably BPD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| Zanarini, Horwood, Wolke, Waylen, Fitzmaurice& Grant; 2011 | A birth cohort of 6330 11-year- old children in Bristol, England, was interviewed about borderline psychopathology in 2002, 2003, and 2004; a community sample of 34,653 American adults was interviewed about borderline psychopathology in 2004 and 2005 | This study had two main objectives. The first was to assess the prevalence of DSM-IV BPD and its constituent symptoms in a community sample of late- latency children. The second was to compare these rates with those found in a community sample of American adults.                                                              | The results of this study suggest that 11-year-old children are about half as likely as adults to meet the DSM-IV criteria for BPD. They also suggest that gender does not play a defining role in symptom expression. Rates of chronic emptiness, physically self-damaging acts, and stormy relationships were very similar in both samples. However, a significantly higher percentage of children than adults reported being angry and moody. By contrast, a significantly higher percentage of adults than children reported being paranoid or dissociated, having a serious identity disturbance, being impulsive, and making frantic efforts to avoid abandonment. In addition, a significantly higher percentage of adults than children met DSM-IV criteria for BPD. Statistically significant but clinically minor gender differences were also found between girls and boys as well as between men and women. |
| Sharp, Ha, Michonski, Venta& Carbone; 2012                 | An inpatient sample of adolescents ( N = 245)                                                                                                                                                                                                              | The aim of the current study was to examine various psychometric properties of the CI-BPD, a promising interview-based measure of adolescent BPD.                                                                                                                                                                                    | As has been found in several adult studies, the confirmatory factor analytic results supported a unidimensional factor structure for the CI-BPD, which indicates that the DSM-IV criteria on which the CI-BPD is based constitute a coherent combination of traits and symptoms, even in adolescents. In addition, other validity criteria were found to be excellent.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| Stepp, Burke, Hipwell& Loeber; 2012                        | Annual longitudinal data from the two oldest cohorts in the Pittsburgh Girls Study ( N = 1233).                                                                                                                                                            | The current study addresses symptoms of ADHD and ODD as potential precursors of BPD in adolescence.                                                                                                                                                                                                                                  | Higher levels of ADHD and ODD scores at the age of 8 years uniquely predicted BPD symptoms at the age of 14 years. In addition, the rate of growth in ADHD scores from the age of 10 to 13 years and the rate of growth in ODD scores from the age of 8 to 10 years uniquely predicted higher BPD symptoms at the age of 14 years.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |

| Authors                                      | Population                                                                                                                        | Description                                                                                                                                                                                                        | Results                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|----------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Bornovalova, Hicks, Iacono& McGue; 2013      | 1280 female adolescent twins between the ages of 14 and 18 years                                                                  | This study examined the developmental course, reciprocal influences, and genetic and environmental factors underlying the co-occurrence of BPD traits and substance use.                                           | Rank-order stability was moderate to high for both BPD traits and substance use, whereas the mean levels of substance use increased substantially from the ages of 14 to 18 years; BPD traits showed a small decline. BPD traits and substance use exhibited concurrent and prospective associations; however, the longitudinal associations dropped to non-significance after accounting for the temporal stability of each trait. Twin analyses revealed that shared environmental factors accounted for the association between BPD traits and substance use at the age of 14 years, but genetic factors account for the association at the age of 18 years.                                    |
| Glenn& Klonsky; 2013                         | 174 adolescents (75.9% female; mean age, 15.13 years) from inpatient and partial hospitalization units                            | This study examined the reliability and validity of BPD in a large sample of adolescent psychiatric patients.                                                                                                      | Approximately 30% of patients in the sample met the criteria for BPD. The nine BPD criteria demonstrated good internal consistency that was equivalent to rates reported in adult samples. In addition, BPD was related to greater clinical severity and impairment as indexed by strong associations with all major Axis I disorders as well as with dimensional measures of depression, anxiety, difficulties with emotion regulation, and impulsiveness. Notably, reliability and validity remained satisfactory even when analyses were limited to younger adolescents between the ages of 12 and 14 years.                                                                                    |
| Michonski, Sharp, Steinberg & Zanarini; 2013 | A population-based sample ( N = 6339) of young adolescents (ages 11 and 12) from the United Kingdom                               | IRT methods were used to investigate the psychometric properties of the DSM-IV BPD criteria. BPD was also assessed with the use of the CI-BPD.                                                                     | A single underlying dimension adequately accounted for covariance among the BPD criteria. Each criterion was found to be discriminating to a degree comparable to what has been reported in adult studies. Five criteria were found to exhibit differential item functioning between boys and girls. However, differential item functioning balanced out for the total interview score.                                                                                                                                                                                                                                                                                                            |
| Noblin, Venta& Sharp; 2013                   | 121 adolescents from an acute care inpatient unit                                                                                 | This study evaluated the reliability and the convergent and criterion validity of the MSI-BPD in an effort to establish the clinical utility of the MSI-PBD as screening measure for BPD in inpatient adolescents. | Findings demonstrated support for the validity of the MSI-BPD when it was used among inpatient adolescents. A clinical cutoff of 5.5 was established.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Sharp, Steinberg, Temple & Newlin; 2014      | A community sample of 964 adolescents (mean age, 15.1 years; 55.9% female) and an independent sample of 371 inpatient adolescents | This study evaluated the BPFSC and developed a short version of the BPFSC through the use of IRT methods.                                                                                                          | The hypothesized four-factor structure was not supported. The unidimensional IRT analysis demonstrated instances of local dependence among item pairs and item responses that were not strongly related to the underlying construct. As a consequence, items were eliminated to create a unidimensional 11-item brief BPFSC (the BPFSC-11). Evidence of the construct validity of scores based on the shortened version was evaluated with the use of an independent inpatient adolescent population. The authors demonstrated similar indices of construct validity as have been observed for the BPFSC total score with the BPFSC-11 scores, and they found evidence of good criterion validity. |

Note: For ease of presentation, studies are reported in chronological order. Bold text indicates review articles.

seems  adequate  ( α =  0.76)  as  well  as  comparable with  the  internal  consistency  observed  with  adult participants  ( α =  0.74)  (18).  Sharp  and  colleagues (25)  demonstrated  that  the  Cronbach's α value  of the  DSM-IV BPD criteria  in  a  large  sample  ( N = 245) of adolescent inpatients was 0.80 when the CIBPD was used to assess BPD. Recently, Michonski and colleagues (26) demonstrated the use of an item response  theory  approach  in  a  large,  populationbased sample (n = 6339) of young adolescents from the  United  Kingdom  (ages  11  and  12).  In  their study,  a  single  underlying  dimension  adequately accounted  for  covariance  among  the  BPD  criteria; moreover, each criterion was found to be discriminating to a degree comparable to what has been reported in adult studies.

As a whole, psychometric data clearly indicate that BPD could be reliably diagnosed during adolescence with  the  use  of  descriptive  diagnostic  criteria  (5). The lower values that were observed for the internal consistency  of  BPD  criteria,  when  compared  with the values of inter-rater reliability for BPD diagnosis,  suggest  that  the  clinical  presentation  of BPD during adolescence may be as heterogeneous as  it  is  during  adulthood.  In  addition,  diagnostic agreement  between  independent  clinicians  and  the research that addresses BPD  diagnosis during adolescence  is  good.  Although  some  studies  have reported disproportionally high prevalence rates for DSM-based  BPD  diagnosis,  with  values  ranging from roughly 11% (27) to 14% (28), these findings were likely to be the result of the unreliable assessment of BPD features and sampling bias (5). Recent studies that were based on a rigorous methodology of BPD assessment and large community  samples  reported  prevalence  rates  for BPD  diagnosis  during  adolescence  that  were  less suspect than the previous findings. With the use of the  CI-BPD  in  a  community  sample  of  6330  11year-old  participants  who  were  interviewed  after their  eleventh  birthdays,  Zanarini  (29)  reported  a base rate of 3.27% for DSM-IV-TR BPD diagnosis. This  finding  closely  matched  the  epidemiological data  regarding  the  prevalence  of  BPD  in  general population samples of adult participants (2). Interestingly,  when  Zanarini  and  colleagues  (22) compared the prevalence of BPD in the community sample  of  6330  11-year-old  participants  with  the prevalence  of  BPD  in  a  community  sample  of 34,653 American adults, they reported that a significantly higher percentage of adults than children  met  the  DSM-IV  criteria  for  BPD  (5.9% vs.  3.2%, respectively). Although BPD criteria may be  over-inclusive  with  regard  to  symptoms  that characterize the developmental period of adolescence (5), prevalence rates of thoroughly assessed  BPD  diagnoses  did  not  advise  against diagnosing BPD during adolescence or even during late  childhood).  Researchers  considered  stability  to be a key defining feature of BPD and emphasized the  persistence  (i.e.,  temporal  stability)  of  BPD diagnosis  over  time  as  the  'gold  standard'  with regard to the reliability of the BPD diagnosis during adolescence (5). Some research that is based primarily  on  community  samples  suggested  that BPD may have concurrent validity during adolescence  (i.e.,  it  is  a  valid  indicator  of  distress and  dysfunction)  but  that  it  is  relatively  unstable over  time  (15,27,30,31);  this  suggests  that  BPD during adolescence may reflect a point-in-time disturbance rather  than  a  chronic  impairment  (32). However, current research indicates that BPD is not particularly  stable  in  adult  samples  either  and  that symptoms are likely to be reduced through treatment  efforts  to  a  subclinical  or  non-clinical level  of  dysfunction  (33,34).  Recent  data  from  a study of 47 adolescent girls who were assessed over a  10-year  period  suggest  a  pattern  of  enduring functional and psychopathological impairments associated  with  poor  outcomes  among  individuals diagnosed with BPD, even if there was symptomatic remittance  (35).  This  finding  is  highly  consistent with the results of Zanarini and colleagues' (36) 16year  follow-up  study  of  adults  with  BPD,  which indicated  that  sustained  symptomatic  remission  is substantially more common than sustained recovery from BPD and that sustained remissions (defined as no longer meeting the study criteria for BPD or for any  other  personality  disorder  per  the  DSM-III-R criteria  (37)  for  a  period  of  two  years  or  longer  or one follow-up period) and recoveries (defined as a Global  Assessment  of  Functioning  score  of  61  or higher)  are  substantially  more  difficult  for  patients with BPD to attain and maintain as compared with patients with other forms of personality disorders.

In  summary, available  research  data  indicate  that BPD can be reliably diagnosed during adolescence. The BPD diagnosis itself  is  likely  to  be  less  stable than it was previously thought during both adolescence and adulthood, and this diagnosis seems to be composed of acute symptoms and traitlike-or  temperament-like-dysfunctional  features. The relevance of an early diagnosis of BPD during adolescence is stressed by the fact that poor outcomes have been observed among young adults who were diagnosed with BPD during adolescence, even in the case of the remission of BPD.

## The construct validity of borderline personality disorder diagnosis during adolescence

A number of research  studies  tried  to  address  the construct  validity  of  BPD  in  adolescents;  these studies  looked  at  whether  a  BPD  diagnosis  during adolescence actually measures what it is intending to measure, and they pointed to the consistent relationships  found  between  BPD  and  associated areas of dysfunction and distress as evidence of the validity of the BPD  diagnosis (18,19,32,38-44). Overall, adolescents with BPD diagnoses, as compared  with  a  control group  of adolescents without  BPD,  demonstrated  the  following  over time:  1)  lower  Global  Assessment  of  Functioning scores and higher scores on self-report measures of acute psychiatric symptoms (e.g., anxiety, depression)  (32);  2)  social  impairment  (e.g.,  fewer and shorter friendships, less enjoyment of others, a lack  of  a  confidant,  the  absence  of  a  romantic relationship,  fewer  social  activities)  (45);  3)  school or work problems (e.g., repeating grades, dropping out of school) (45); 4) higher rates of comorbidities involving Axis I diagnoses (18,40,41,44); 5) a higher frequency of contact with the police as a result of antisocial behavior (39,45); and 6) a higher frequency of drug use (46).

Becker and colleagues (45) reported that the mean inter-criterion  correlations  for  BPD  criteria  were low  but  also  similar  across  adolescent  and  adult groups  (.28 and  .26, respectively). Discriminant validity was adequate and similar for the adolescents and  adults  as  evidenced  by  low  diagnostic  overlap measured through inter-category mean intercriterion correlations (.07 and .06, respectively). In a study  of  the  diagnostic  efficiency  of  BPD  criteria between adolescent and adult inpatients, Becker and colleagues  (38)  found  no  significant  differences  in the base rates of BPD between the two groups nor among  any  of  the  BPD  criteria;  similar  findings were  also  obtained  in  Segal-Trivitz  and  colleagues' study (47). Although some studies reported a substantial  overlap  among  the  individual  symptom criteria  of  BPD  and  other  Axis  I  and  Axis  II disorders (48,49), several studies indicated that some BPD in adolescents can be reliably distinguished from other Axis I disorders (18,40,41,44).  Recently,  Glenn  and  Klonsky  (50) recruited a sample of 174 adolescents (75.9% female;  mean  age,  15.13  years)  from  the  inpatient and partial hospitalization units of a hospital in the northeastern United States that provides short-term treatment for adolescents with severe psychopathology.  As  has  been  found  in  previous studies, approximately 30%  of patients in the current sample met the criteria for BPD. The nine BPD criteria demonstrated good internal consistency, and this was equivalent to rates reported with adult samples. In addition, BPD was related to greater clinical severity and impairment as indexed by strong associations with all major Axis I disorders  as  well  as  with  dimensional  measures  of depression, anxiety, difficulties with emotion regulation, and impulsiveness.

Studies  showed  that  adolescents  diagnosed  with BPD at baseline continued to experience some level of  affective  disturbance  or  behavioral  disruption even  during  remission  from  BPD  (i.e.,  when  they did  not  meet  the  criteria  for  BPD  diagnosis  any longer) (35,43). The finding that functional impairments  persisted  among  adolescents  who  no longer  met  BPD  criteria,  particularly  for  affective disturbances,  is  consistent  with  the  findings  in  the adult literature.

Available scientific evidence-together with recent studies based on the thorough assessment of DSM-IV BPD criteria in a large, community-based sample of adolescents (26)-indicate that a dimensional perspective may be particularly important for conceptualizing BPD pathology among youth. This type of perspective is better able to  account  for  the  developmental  fluctuations  and increased  heterogeneity that  have  been  reported  in younger samples.

The high level of comorbidity between BPD and several Axis I disorders-particularly mood disorders, anxiety disorders, substance abuse, eating disorders, post-traumatic stress disorder, and attention-deficit/hyperactivity  disorder  (ADHD)that was frequently reported in the scientific literature called into question the diagnostic specificity of BPD during adolescence (8). However, it should be observed that the comorbidity rate between Axis I disorders and BPD that is observed in adolescent samples is consistent with the epidemiological data that have been obtained  with  adult  BPD  samples.  Co-occurrence base  rates  between  BPD  and  Axis  I  diagnoses among  adults  are  usually  in  the  range  of  10%  to 30%  for  bipolar  I/II  disorders,  30%  to  50%  for eating disorders and post-traumatic stress disorder, 50% for substance use disorder,  and  50%  to  60% for anxiety disorders (51-53).

The differential diagnosis between  BPD  and mood disorders may be problematic, because mood disorders  are  themselves  poorly  characterized  in adolescents; this may be particularly difficult in the case  of  bipolar  II  disorder.  However,  it  should  be stressed  that  the  affective  shifts  of  BPD  oscillate between  anger  and  dysphoria  rather  than  between elation and depression (as bipolar disorders do), and they  tend  to  be  rapidly  reversible  and  exquisitely reactive to the relationship context  rather than endogenously driven and episodic (54,55).

Studies have demonstrated an important association between ADHD and late BPD (56-61). ADHD  and  BPD  share  some  clinical  features, particularly impulsivity and emotional instability (60). Given the similarities in symptom presentation,  one  might  think  that  ADHD  and BPD  are  different  modes  of  the  same  disorder.

However,  states  of  inner  tension  (62),  which  are often regulated through self-injurious behavior and repeated suicidal ideation as well as  temporary stress-related paranoid ideation or dissociative symptoms, are typical of BPD but not of ADHD. Inadequate efforts to prevent abandonment in intense but unstable relationships, the marked instability  of  identity  and  extreme  alterations  in thinking (i.e., devaluation vs. idealization), and feelings  of  emptiness  are  features  of  BPD.  These severe symptoms  rarely occur in patients with ADHD, whereas inattention and hyperactivity (the core  symptoms  of  ADHD)  are  not  considered typical  of  patients  with BPD; this suggests marked differences between the two disorders (63). Moreover, impulsivity-a severely impairing characteristic of patients with both disorders (64) is  primarily  driven  by  affective  and  interpersonally sensitive aspects in those with  BPD, whereas deficits in attentional and cognitive processing account for the behavior inhibition problems referred to as impulsivity in  those with ADHD (63). In sum, ADHD,  residual  type, should not be misdiagnosed  as  BPD,  and  emerging  BPD  should not be confused with residual ADHD.

Dysfunctions in social cognition (i.e., understanding behavior in mental state terms, theory of mind, or mentalizing) have been proposed as  explanations  for  disturbances  of  interpersonal behavior in patients with BPD (24;65-67). Individuals who have been diagnosed with neurodevelopmental  conditions  such  as  autism  or Asperger  syndrome  have  core  deficits  in  social cognition  (68,69).  However,  it  is  noteworthy  that hypermentalizing (i.e., over-interpretive mental state reasoning)  was  associated  with  BPD  features  in adolescents  (24),  whereas  insufficient  mental  state reasoning  that  resulted  in  incorrect  and  reduced mental state attribution were reported for adolescents  with  autism  (70).  The  core  features  of BPD  (i.e., impulsivity, affective instability, and instability  in  interpersonal  relationships) are  not typical for autism spectrum disorders and pervasive developmental disorders (71). A recent study revealed  clear  differences  between  the  personality profile of adults with autism spectrum disorders and the personality and personality pathology profiles of those with narcissistic personality disorders or BPD and nonclinical controls, respectively (72).

The warning signs of emerging borderline personality disorder during  adolescence  and  the  measures  specifically  designed  to

diagnose this condition during adolescence

Research  evidence  indicates  that  there  is  no  single symptom that is predictive of BPD diagnosis during adolescence  (8);  rather,  a  pattern  of  two  to  three selected  BPD  symptoms  that  are  evident  during adolescence seemed to be highly predictive of later BPD diagnosis. Early studies reported that symptoms  with  the  highest  predictive  power  (i.e., the  most  stable  symptoms)  for  adolescents  were chronic feelings of emptiness as well as inappropriate  and  intense  anger  (20).  Additional studies  have  also  consistently  identified  symptoms of identity disturbance, affective instability,  and inappropriate,  intense  anger  as  having  the  greatest predictive power for BPD in adolescents (38;42-44). The positive predictive power of these three symptoms  is  almost  identical  to  that  identified  in the adult BPD literature (19,38), which suggests that apparent key symptom criteria are valid across age groups.  The  role  of  identity  disturbance  as  a  core diagnostic  feature  of  BPD  during  adolescence  was strongly  supported  by  Westen  and  colleagues  (73); in  their  study,  identity  disturbance  in  adolescents appeared to be highly similar to identity disturbance in adults, and it was significantly predictive of BPD symptoms. Recently, Michonski and colleagues (26) reported that a single underlying dimension adequately  accounted  for  covariance  among  the BPD  criteria. Each  criterion was  found  to be discriminating to a degree comparable to what has been reported in adult studies. As in adult findings (74,75),  five  BPD  criteria  were  found  to  exhibit differential item functioning (i.e., differences in the relation of an item to the latent trait across population subgroups) between boys and girls. Michonski and colleagues (26) found paranoid ideation  and  identity  disturbance  to  be  the  most discriminating  DSM-IV  BPD  criteria  in  boys  and girls, respectively. BPD  characteristics involving emotional  reactivity  or  poor  impulse  control  (i.e., inappropriate and intense anger or difficulty controlling anger, affective instability, and impulsivity)  were  easier  to  endorse  as  compared with  suicidal  behaviors  (girls)  and  abandonment fears  (boys),  which  were  more  difficult  to  endorse (i.e., they required the highest level of BPD liability).

Deliberate non-suicidal self-harm deserves a particular  consideration.  Although  deliberate  selfharm is a common feature of BPD during adolescence (76), it is neither necessary nor sufficient  for  the  diagnosis  of  this  condition  (e.g., 77). However, deliberate self-harm during adolescence should be carefully assessed as a result of four key issues: 1) Deliberate self-harm is highly addictive, because it releases opiates that relieve the pain associated with and the sensitivity to abandonment, rejection, or difficulties in attunement associated with the reduced opiates that are shown to be implicated in self-injurious behavior in those with BPD  (78). 2) During adolescence, deliberate non-suicidal self-harm significantly overlaps with suicidal behavior, including  instances  of  unintended  accidental  death or  near  death  during  the  course  of  deliberate  selfharm (76). 3) Deliberate non-suicidal self-harm is an instance  of  non-mentalizing  behavior  (8)  that  is consistently  associated  with  emotional  neglect  (79) and dissociation triggered by abandonment, rejection, or a lapse in attunement (80). 4) Deliberate  non-suicidal  self-harm  is  a  marker  of mentalizing  collapse,  which  is  strongly  associated with  dissociation  and  evocative  of  intense  (albeit frequently  chaotic  and  problematic)  reactions  in others; these include acute hospitalizations and desperate  efforts  of  parental  control  mixed  with feelings of guilt, shame, rage, and despair that spur coercive  cycles  that  lead  to  further  impairment  in the  mentalistic  abilities  of  both  adolescents  with BPD and their parents.

Recent data indicate that selected childhood disorders  and  behavioral  problems  may  represent childhood  antecedents  of  emerging  BPD  features during adolescence (81).  Common  factors that underlie  ADHD  and  BPD  (e.g.,  behavioral  and neurocognitive  impairments)  as  well  as  those  that underlie  oppositional  defiant  disorder  (ODD)  and BPD (e.g., affective and interpersonal disturbances) point to possible developmental links between these childhood  disorders  and  BPD.  Burke  and  Stepp (82)-with  the  use  of  prospective  data  from  the Developmental  Trends  Study  (83)  a  clinic-referred sample  of  177  boys-found  that  childhood  and adolescent symptoms of ODD and ADHD as well as  marijuana  use  predicted  BPD  symptoms  at  the age  of  24  years.  Interestingly,  conduct  disorder, depression,  and  anxiety  were  not  related  to  BPD symptoms  in  young  adulthood  in  this  study.  This finding was replicated by Stepp and colleagues (84) in a study based on data from 1233 girls who ranged in  age  from  8 to  14  years. The  authors found that ADHD  and  ODD  symptoms  at  age  8  predicted BPD  symptoms  at  age  14;  moreover,  the  rate  of growth of ADHD symptoms from the ages of 8 to 10 years and the rate of growth of ODD symptoms from  the  ages  of  10  to  13  years  predicted  BPD symptoms at age 14. These patterns of prospective associations were not found for conduct disorder or depression at that age of 14 years (84). Both studies found a similar  pattern  of  results  even  though  the samples were quite unique, with one consisting of a clinical sample of boys (82) and the other comprising  a  high-risk  community  sample  of  girls (84). Most of the discriminating BPD features (i.e., the core diagnostic features) seen during adolescence  are  summarized  in  Table  1.  Although these  warning  signs  of  emerging  BPD  may  be captured  by  a  clinician  during  a  clinical  interview, the early identification and treatment of BPD would be  greatly  enhanced  by  the  careful  and  accurate assessment of personality pathology in adolescents. As Sharp and colleagues (25) pointed out, valid and reliable  instruments  that  are  both  time-  and  costeffective may complement the clinical assessment of BPD features during adolescence. Such instruments should  take  into  account  the  recent  emphasis  on dimensional models of maladaptive personality functioning (85), especially where youth are concerned, because categorical approaches to personality  assessment  focus  narrowly  on  clinically relevant symptoms and do not allow for the study of the entire range of BPD symptoms (86).

TABLE 2. Core Diagnostic Features of Borderline Personality Disorder during Adolescence

|                          | Borderline Personality Disorder during Adolescence                                                                                                                               |
|--------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Core diagnostic features | Identity disturbance (particularly for girls) Inappropriate, intense anger Paranoid ideation (boys) Chronic feelings of emptiness (deliberate self-harm, dissociation proneness) |

Note: No single diagnostic element is suggestive of a borderline personality disorder (BPD) diagnosis during adolescence. Rather, a pattern of two to three diagnostic criteria may be suggestive of emerging BPD in the adolescent population. The diagnostic criteria given in parentheses indicate characteristics of BPD that frequently occur as part of the clinical presentation of BPD during adolescence, although they lack diagnostic specificity.

The assessment of symptoms across the full latent trait of BPD allows for the identification of not only those  individuals  who  are  demonstrating  clinically significant levels of symptomatology but also those who  may  be  considered  at  risk  (87).  Therefore, consistent with the developmental psychopathology principles of homotypic and heterotypic continuity, dimensional approaches allow for the characterization of all possible developmental trajectories  toward  or  away  from  psychopathology over  time  as  children  mature  through  adolescence and into early adulthood (87).

We  have  previously  reported  that  Zanarini  (21) developed the CI-BPD, a semi-structured interview that was specifically designed to yield BPD diagnoses during adolescence. However, the availability  and  routine  use  of  a  brief  screen  for BPD could potentially permit for the earlier detection of BPD in clinical samples, perhaps even before the development of more severe externalizing  indicators  (88).  The  availability  of  a brief and reliable screen for BPD would increase the likelihood that practitioners alerted to the possibility of  this  condition  would  pursue  a  more  formal evaluation (89,90). This is particularly important for adolescent populations; BPD is commonly misdiagnosed or missed completely in these individuals,  because  emotional  dysregulation  and externalizing behavior can be explained as developmentally appropriate, depending on its magnitude (91).

Reliable  and  valid  self-report  measures  for  the assessment of BPD during adolescence are currently available: for example, the McLean Screening Instrument for Borderline Personality Disorder (MSI-BPD; 89,92); the Borderline Personality Questionnaire (BPQ; 93); the Borderline Personality Inventory (BPI; 94,95); the Personality Assessment Inventory  (96);  and  the  Millon  Adolescent  Clinical Inventory (97,98). Chanen and colleagues (88) showed  that  the  BPQ  achieves  a  good  balance  of the  properties  desired  in  a  screening  instrument. However,  its  length  is  a  significant  drawback,  and this may preclude more widespread clinical application (88). Thus, self-report measures for the assessment of BPD during adolescence are too long to be of practical use for the screening of adolescent populations for BPD (e.g., the BPQ), or they may have been originally developed to assess  BPD among adults (e.g., the BPI, the MSI-BPD). This is not to say that measures that were originally developed for adults will not work for adolescents. Noblin,  Venta,  and  Sharp  (89)  recently  established the  clinical  utility  of  the  MSI-BPD  as  a  screening measure  for  BPD  in  a  sample  of  121  inpatient adolescents; their findings demonstrated support for the validity of the MSI-BPD when it is used among inpatient  adolescents,  and  a  clinical  cutoff  of  5.5 was established. However, the availability of measures specifically designed to capture  BPD features as they manifest themselves during adolescence would be of consistent help to clinicians for detecting the warning signs of emerging BPD.

In  an  effort  to  fill  this  gap  in  the  assessment  of BPD during adolescence, Crick and colleagues (86) proposed the Borderline Personality Features Scale for  Children (BPFSC), which seems to represent a promising instrument for screening for BPD during adolescence, particularly in its 11-item version (87). Crick and colleagues (86) developed this self-report instrument by modifying the borderline scale of the Personality Assessment Inventory (PAI) (96), which is  a  reliable  and  valid  tool  used  to  assess  BPD features among  adults. Although an adolescent version of the PAI was developed, its items remained largely unchanged from the adult version. The  BPFSC  included  24  age-appropriate  items  to reflect the original four domains of the PAI: affective instability, identity problems, negative relationships, and self-harm. In a community sample  of  400  fourth  through  sixth  graders,  Crick and  colleagues  (86)  established  evidence  for  the construct validity and moderate stability of the 24item BPFSC. Evidence for criterion validity against an  interview-based  diagnostic  measure  of  BPD  in inpatient adolescents (23) and concurrent validity in a  community  sample  of  boys  (99)  have  also  been established. Recently, with the use of item response theory methods, Sharp and colleagues (87) examined individual item performance of the BPFSC in a large community sample of adolescents ( N =  964).  The  hypothesized  four-factor  structure of  the  24-item  BPFSC  was  not  supported.  The unidimensional item response theory analysis showed instances of local dependence among item pairs as well as item  responses that  were  not strongly  related  to  the  underlying  construct.  As  a consequence,  items  were  eliminated  to  create  the unidimensional 11-item brief BPFSC known as the BPFSC-11. With  the  use  of  a  different  sample  of 371 inpatient adolescents, Sharp and colleagues (87) demonstrated similar indices of construct validity as observed for the BPFSC  total score with the BPFSC-11  scores  and  found  evidence  for  good criterion  validity.  In  particular,  receiver  operating characteristic  analyses  showed  that  the  BPFSC-11 had  an  area  under  the  curve  value  of  .80,  which indicates  good  diagnostic  accuracy;  sensitivity  and specificity  analyses  demonstrated  an  ideal  cutoff point of 34 (sensitivity = .740; specificity = .714) for the BPFSC-11 (87). Although these findings are far from conclusive, the BPFSC-11 seems to represent the only dimensional measure to date that has been specifically  developed  to  yield  a  reliable  and  valid assessment of BPD features in adolescents.

## Discussion

Notwithstanding  the  controversies  that  historically surrounded the diagnosis of BPD during adolescence,  available  scientific  evidence  indicates that  BPD  can  be  reliably  and  validly  diagnosed  in adolescent  clients.  Empirical  studies  suggest  that, although  there  is  a  subgroup  of  severely  affected adolescents  for  whom  the  BPD  diagnosis  remains stable  over  time,  there  appears  to  be  a  less  severe subgroup  that  moves  in  and  out  of  the  diagnosis. The rate of diagnostic stability of BPD in adolescents is comparable to that seen in adults, and a  select  few  symptom  criteria  have  consistently emerged as significant predictors of BPD retention in both adolescent and adult samples (34,81). Available evidence recommends that BPD in adolescents  be  conceptualized  from  a  dimensional or  continuous  approach  rather  than  a  categorical approach,  because  a  dimensional  approach  may better account for the developmental variability and the  heterogeneity  found  among  adolescents  (5). Consistent  with  Miller  and  colleagues'  suggestions (5),  current  literature  indicates  that  mental  health practitioners should strongly consider formally assessing for BPD, either categorically or continuously, when working with adolescents. Reliable  and  valid  self-report  measures  as  well  as semi-structured interviews and observer-rated measures  are  currently  available  to  clinicians  and researchers for the assessment  of  BPD  during adolescence.  Regardless  of  the  presence  of  a  fullfledged diagnosis, BPD symptoms in adolescentseven  if  there  are  fewer  than  five-may  indeed accurately reflect significant distress and dysfunction that requires intervention (5). Although it  is  known  that  there  may  be  negative  stigma associated with BPD diagnosis and that this poses a serious concern with regard to applying the diagnosis,  available  data  strongly  indicate  that  this stigma should not preclude clinicians from assessing for  BPD  and  carefully  considering  BPD  diagnosis when warranted (5).

The  impact  of  the  changes  to  the  personality disorder general criteria and BPD diagnostic criteria that  are  incorporated  in  Section  III  of  the  DSM-5 will  significantly  affect  future  research  in  this  area. Although the DSM-5 model of personality disorders is not without  criticism (see, for example,  the position summarized in Krueger and Eaton's article [100]) and it has only been added to the provisional section of the DSM-5  (i.e., Section III), the proposed  removal  from  the  DSM-5  Section  III criteria of any reference to adult age for the diagnosis of personality disorders (101) will be likely to prompt the assessment of BPD during adolescence.  The  shift  to  a  hybrid  dimensionalcategorical  model  for  personality  as  well  as  for personality disorder assessment and diagnosis in the DSM-5  is  highly  consistent  with  Michonski  and colleagues'  findings  (26)  regarding  the  need  for flexible  diagnostic  systems  for  the  assessment  of BPD during adolescence.

The  development  and  refinement  of  diagnostic criteria and assessment instruments specifically designed  to  capture  BPD  manifestations  during adolescence  and  childhood  is  clearly  among  the priorities of the agenda for future research involving BPD. Current evidence indicates that BPD does not appear 'out of the blue' during adolescence; rather, symptoms of ADHD and ODD during childhood or other childhood problem behaviors usually precede the emergence of BPD during adolescence (102).  Of  course,  these  data  do  not  imply  that  all children  with  ADHD  or  ODD  will  develop  BPD later  during  their  lives.  Longitudinal  studies  have shown  that  BPD  is  frequently  diagnosed  in  adult patients  who  had  been  diagnosed  with  ADHD  in childhood.  The  question  of  whether  ADHD  and BPD randomly co-occur as comorbidities or whether they have similar origins or share common pathological  mechanisms  remains  unresolved  (63). It  is  hoped  that  future  studies  will  illuminate  the developmental pathways that lead some children to develop BPD during adolescence or adulthood and that both risk factors and protective factors will be identified.  The  co-occurrence  of  other  personality disorders  (as  well  as  other  mental  disorders)  with BPD during adolescence and the impact of this on the  course,  outcome,  and  treatment  response  of BPD  are  likely  to  receive  special  attention  in  the near future. In adult patients, BPD  has  been reported to be characterized by high co-occurrence rates with other disorders, particularly bipolar disorder, narcissistic personality disorder, and schizotypal  personality  disorder  (103).  It  has  also been  found  that  the  co-occurrence  of  BPD  with other  personality  disorders  seems  to  influence  the likelihood of remission and the time to remission of patients  with  BPD  (104).  These  findings  clearly highlight  the  need  to  study  the  impact  of  cooccurring personality disorders on the clinical course of BPD in adolescent samples.

The identification of very early manifestations of BPD during childhood is likely to represent a major research  task  in  the  future.  Some  studies  have suggested  that  BPD  symptoms  are  likely  to  be detectable at an early age; specific features of BPD (e.g.,  self-harm,  traits  of  impulsivity  and  affective instability)  are  present  during  childhood,  and  they are predictive of a BPD diagnosis during adulthood (77,105).  These  few  studies  do  not  allow  for  the drawing of any firm conclusion about the construct validity  of  a  BPD  diagnosis  during  childhood,  but they indicate the relevance of this research topic and represent a path for future studies.

## Conclusions

A  qualitative review of the scientific literature suggested that adolescence is a critical point for the early  identification  and  therapeutic  treatment  of BPD. Available research data indicate that BPD can be  reliably  and  validly  diagnosed  in  adolescents. Research  evidence  indicates  that  there  is  no  single symptom that is predictive of  later  BPD  diagnosis during adolescence; rather, a pattern of two to three selected  BPD  symptoms  that  are  evident  during adolescence seemed to be highly predictive of later BPD  diagnosis,  particularly  when  measures  that were specifically designed to assess for BPD during adolescence  were  used  as  part  of  the  assessment process.

## References

1. Leichsenring F, Leibing E, Kruse J, New A, Leweke F. Borderline personality disorder. Lancet 2011;377(9759):74-84.
2. Lenzenweger M. Epidemiology of personality disorders. Psychiatr Clin North Am 2008;31(3):395-403

3. American Psychiatric Association. Diagnostic and statistical manual of mental disorders, fifth edition. Washington, DC: American Psychiatric Association; 2013.
4. Chanen A. Outcomes in women diagnosed with borderline personality disorder in adolescence: early detection and timely intervention are fundamental. J Can Acad Child Adolesc Psychiatry 2011;20(3):175.
5. Miller A, Muehlenkamp J, Jacobson C. Fact or fiction: Diagnosing borderline personality disorder in adolescents. Clin Psychol Rev 2008;28(6):969-81.
6. Sharp C, Williams L, Ha C, Baumgardner J, Michonski J, Seals R, et al. The development of a mentalization-based outcomes and research protocol for an adolescent inpatient unit. Bull Menninger Clin 2009;73(4):311-38.
7. Bleiberg E. Treating personality disorders in children and adolescents. New York: Guilford Press; 2001.
8. Bleiberg E, Rossouw T, Fonagy P. Adolescent breakdown and emerging borderline personality disorder. In: Bateman AW & Fonagy P (eds). Handbook of metalizing in mental health practice. Arlington: American Psychiatric Publishing; 2011; p.463-509.
9. Chanen A, Jackson H, McGorry P, Allot K, Clarkson V, Yuen H. Two-year stability of personality disorder in older adolescent outpatients. J Pers Disord 2004;18(6):526-41.
10. Ludolph P, Westen D, Misle B, et al. The borderline diagnosis in adolescents: symptoms and developmental history. Am J Psychiatry 1990;147(4):470-76.
11. Winograd G, Cohen P, Chen H. Adolescent borderline symptoms in the community: prognosis for functioning over 20 years. J Child Psychol Psychiatry 2008;49(9):933-41.
12. Kernberg P, Weiner A, Bardenstein K: Personality disorders in children and adolescents. New York: Basic Books; 2000.
13. Irwin C Jr. Risk taking behaviors in the adolescent patient: Are they impulsive? Pediatr Ann 1989;18(2):122-4.
14. Irwin C Jr, Burg S, Uhler Cart C. America's adolescents: Where have we been, where are we going? J Adolesc Health 2002;31(6):91-121.
15. Bondurant H, Greenfield B, Tse S. Construct validity of the adolescent borderline personality disorder: a review. J Can Acad Child Adolesc Psychiatry 2004;13(3):53-7.
16. Chanen A. Review: Urgent need for RCT evidence on effectiveness of crisis interventions for borderline personality disorder [Comment]. Evid Based Ment Health 2012;15:94.
17. Sharp C, Romero C. Borderline personality disorder: A comparison between children and adults. Bull Menninger Clin 2007;71:85-114.
18. Becker D, Mcglashan T, Grilo C. Exploratory factor analysis of borderline personality disorder criteria in hospitalized adolescents. Compr Psychiatry 2006;47(2):99-105.
19. Blais M, Hilsenroth M, Fowler J. Diagnostic efficiency and hierarchical functioning of the DSM-IV borderline personality disorder criteria. J Nerv Ment Dis 1999;187(3):167-73.
20. Garnet K, Levy K, Mattanah J, Edell W, Mcglashan T. Borderline personality disorder in adolescents: ubiquitous or specific? Am J Psychiatry 1994;151(9):1380-2.
21. Zanarini MC: Childhood Interview for DSM-IV Borderline Personality Disorder (CI-BPD). Belmont, MA: McLean Hospital, 2003.
22. Zanarini M, Horwood J, Wolke D, Waylen A, Fitzmaurice G, Grant B. Prevalence of DSM-IV borderline personality disorder in
21. two community samples: 6,330 English 11-year-olds and 34,653 American adults. J Pers Disord 2011;25(5):607-19.
23. Chang B, Sharp C, Ha C. The criterion validity of the Borderline Personality Features Scale for Children in an adolescent inpatient setting. J Pers Disord 2011;25(4):492-503.
24. Sharp C, Pane H, Ha C, et al. Theory of mind and emotion regulation difficulties in adolescents with borderline traits. J Am Acad Child Adolesc Psychiatry 2011;50(6):563-73.
25. Sharp C, Ha C, Michonski J, Venta A, Carbone C. Borderline personality disorder in adolescents: evidence in support of the Childhood Interview for DSM-IV Borderline Personality Disorder in a sample of adolescent inpatients. Compr Psychiatry. 2012;53(6):765-74.
26. Michonski J, Sharp C, Steinberg L, Zanarini M. An item response theory analysis of the DSM-IV borderline personality disorder criteria in a population-based sample of 11-to 12-year-old children. Personal Disord 2013;4(1):15-22.
27. Bernstein D, Cohen P, Velez C, Schwab-Stone M, Siever L, Shinsato L. Prevalence and stability of the DSM-III-R personality disorders in a community-based survey of adolescents. Am J Psychiatry 1993;150(8):1237-43.
28. Chabrol H, Montovany A, Chouicha K, Callahan S, Mullet E. Frequency of borderline personality disorder in a sample of French high school students. Can J Psychiatry 2001;46(9):847-9.
29. Zanarini MC: Update on borderline personality disorder. Presentation at the Conference of the National Education Alliance for Borderline Personality Disorder; 2003; New York, White Plains.
30. Korenblum M, Marton P, Golombek H, Stein B. Personality status: changes through adolescence. Psychiatr Clin North Am 1990;13(3):389-99.
31. Mattanah J, Becker D, Levy K, Edell W, McGlashan T. Diagnostic stability in adolescents followed up 2 years after hospitalization. Am J Psychiatry 1995;152(10):889-94.
32. Levy K, Becker D, Grilo C, et al. Concurrent and predictive validity of the personality disorder diagnosis in adolescent inpatients. Am J Psychiatry 1999;156(10):1522-8.
33. Gunderson J, Stout R, McGlashan T, et al. Ten-year course of borderline personality disorder: psychopathology and function from the Collaborative Longitudinal Personality Disorders Study. Arch Gen Psychiatry 2011;68(8):827-37.
34. Zanarini M, Frankenburg F, Hennen J, Reich D, Silk K. The McLean Study of Adult Development (MSAD): overview and implications of the first six years of prospective follow-up. J Pers Disord 2005;19(5):505-23.
35. Biskin R, Paris J, Renaud J, Raz A, Zelkowitz P. Outcomes in women diagnosed with borderline personality disorder in adolescence. J Can Acad Child Adolesc Psychiatry 2011;20(3):168.
36. Zanarini M, Frankenburg F, Reich D, Fitzmaurice G. Attainment and stability of sustained symptomatic remission and recovery among patients with borderline personality disorder and axis II comparison subjects: a 16-year prospective follow-up study. Am J Psychiatry 2012;169(5):476-83.
37. American Psychiatric Association: Diagnostic and statistical manual of mental disorders, third edition, revised. Washington DC: American Psychiatric Association; 1987.
38. Becker D, Grilo C, Edell W, McGlashan T. Diagnostic efficiency of borderline personality disorder criteria in hospitalized adolescents: comparison with hospitalized adults. Am J Psychiatry 2002;159(12):2042-7.
39. Chabrol H, Leichsenring F. Borderline personality organization and psychopathic traits in nonclinical adolescents: relationships of

identity diffusion, primitive defense mechanisms and reality testing with callousness and impulsivity traits. Bull Menninger Clin 2006;70(2):160-70.

40. Chabrol H, Montovany A, Callahan S, Chouicha K, Ducongé E. Factor analyses of the DIB-R in adolescents. J Pers Disord 2002;16(4):374-84.
41. Grilo C, Becker D, Edell W, McGlashan T. Stability and change of DSM-III-R personality disorder dimensions in adolescents followed up 2 years after psychiatric hospitalization. Compr Psychiatry 2001;42(5):364-68.
42. McManus M, Brickman A, Alessi N, Lexington Grapentine W. Borderline personality in serious delinquents. Compr Psychiatry 1984;25(4):446-54.
43. Meijer M, Goedhart A, Treffers P. The persistence of borderline personality disorder in adolescence. J Pers Disord 1998;12(1):1322.
44. Pinto A, Grapentine W, Francis G, Picariello C. Borderline personality disorder in adolescents: affective and cognitive features. J Can Acad Child Adolesc Psychiatry 1996;35(10):1338-43.
45. Becker D, Grilo C, Morey L, Walker M, Edell W, McGlashan T. Applicability of personality disorder criteria to hospitalized adolescents: evaluation of internal consistency and criterion overlap. J Can Acad Child Adolesc Psychiatry 1999;38(2):200-05.
46. Bornovalova M, Hicks B, Iacono W, McGue M. Longitudinal twin study of borderline personality disorder traits and substance use in adolescence: Developmental change, reciprocal effects, and genetic and environmental influences. Personal Disord 2013;4(1):23-32.
47. Segal-Trivitz Y, Bloch Y, Goldburt Y, Sobol-Havia D, Levkovitch Y, Ratzoni G. Comparison of symptoms and treatments of adults and adolescents with borderline personality disorder. Int J Adolesc Med Health 2006;18(2):215-20.
48. Becker D, Grilo C, Edell W, McGlashan T. Comorbidity of borderline personality disorder with other personality disorders in hospitalized adolescents and adults. Am J Psychiatry 2000;157(12):2011-6.
49. Crawford T, Cohen P, Brook J. Dramatic-erratic personality disorder symptoms: II. Developmental pathways from early adolescence to adulthood. J Pers Disord 2001;15(4):336-50.
50. Glenn CR Klonsky ED. Reliability and validity of borderline personality disorder in hospitalized adolescents. J Can Acad Child Adolesc Psychiatry 2013;22(3):206-11.
51. Kutcher S, Marton P, Korenblum M. Adolescent bipolar illness and personality disorder. J Can Acad Child Adolesc Psychiatry 1990;29(3):355-8.
52. Lewinsohn P, Zinbarg R, Seeley J, Lewinsohn M, Sack W. Lifetime comorbidity among anxiety disorders and between anxiety disorders and other mental disorders in adolescents. J Anxiety Disord 1997;11(4):377-94.
53. Muratori F. Personality disorders in eating disorders during adolescence. J Psychopathol 2003;9:243-50.
54. Henry C, Mitropoulou V, New A, Koenigsberg H, Silverman J, Siever L. Affective instability and impulsivity in borderline personality and bipolar II disorders: similarities and differences. J Psychiatr Res 2001;35(6):307-12.
55. Koenigsberg H, Harvey P, Mitropoulou V, et al. Characterizing affective instability in borderline personality disorder. Am J Psychiatry 2002;159(5):784-8.
56. Miller CJ, Flory JD, Miller SR, Harty SC, Newcorn JH, Halperin JM. Childhood attention-deficit/hyperactivity disorder and the emergence of personality disorders in adolescence: a prospective follow-up study. J Clin Psychiatry 2008;69(9):1477-84.
57. Distel MA, Carlier A, Middeldorp CM, Derom CA, Lubke GH, Boomsma DI. Borderline personality traits and adult attentiondeficit hyperactivity disorder symptoms: a genetic analysis of comorbidity. Am J Med Genet B Neuropsychiatr Genet 2011;156B(7):817-25.
58. van Dijk FE, Lappenschaar M, Kan CC, Verkes RJ, Buitelaar JK. Symptomatic overlap between attention-deficit/hyperactivity disorder and borderline personality disorder in women: the role of temperament and character traits. Compr Psychiatry 2012;53(1):3947.
59. van Dijk FE, Lappenschaar M, Kan CC, Verkes RJ, Buitelaar JK. Lifespan attention deficit/hyperactivity disorder and borderline personality disorder symptoms in female patients: a latent class approach. Compr Psychiatry 2012;53(1):39-47.
60. Carlotta D, Borroni S, Maffei C, Fossati A. On the relationship between retrospective childhood ADHD symptoms and adult BPD features: the mediating role of action-oriented personality traits. Compr Psychiatry 2013;54(7):943-52.
61. Storebø OJ, Simonsen E. Is ADHD an early stage in the development of borderline personality disorder? Nord J Psychiatry 2014;68(5):289-95.
62. Wolff S, Stiglmayr C, Bretz HJ, Lammers CH, Auckenthaler A. Emotion identification and tension in female patients with borderline personality disorder. Br J Clin Psychol 2007;46:347-60.
63. Matthies SD, Philipsen A. Common ground in Attention Deficit Hyperactivity Disorder (ADHD) and Borderline Personality Disorder (BPD)-review of recent findings. BPDED 2014;1(1):313.
64. Wender PH, Wolf LE, Wasserstein J. Adults with ADHD. An overview. Ann N Y Acad Sci 2001;931:1-16.
65. Fonagy P, Steele H, Moran G, Steele M, Higgitt A. The capacity for understanding mental states: the reflective self in parent and child and its significance for security of attachment. Infant Ment Health J 1991;12:201-18.
66. Sharp C, Fonagy P. Social cognition and attachment-related disorders. In: Sharp C, Fonagy P, Goodyer I (eds). Social cognition and developmental psychopathology. Oxford: Oxford University Press; 2008, p. 269-302.
67. Fonagy P, Target M. Playing with reality III: the persistence of dual psychic reality in borderline patients. Int J Psychoanal 2000;81:85374.
68. Baron-Cohen S. Mindblindness. Cambridge, Mass: MIT Press; 1997.
69. Jolliffe T, Baron-Cohen S. The strange stories test: A replication with high-functioning adults with autism or Asperger syndrome. J Autism Dev Disord 1999;29(5):395-406.
70. Kaland N, Callesen K, Moller-Nielsen A, Mortensen E, Smith L. Performance of children and adolescents with Asperger syndrome or high-functioning autism on advanced theory of mind tasks. J Autism Dev Disord 2008;38(6):1112-23.
71. Lugnegaard T, Hallerback M, Gillberg C. Personality disorders and autism spectrum disorders: What are the connections? Compr Psychiatry 2012;53(4):333-40.
72. Strunz S, Westphal L, Ritter K, Heuser I, Dziobek I, Roepke S. Personality pathology of adults with autism spectrum disorder without accompanying intellectual impairment in comparison to adults with personality disorders. J Autism Dev Disord 2014:1-13. doi: 10.1007/s10803-014-2183-x.
73. Westen D, Betan E, Defife J. Identity disturbance in adolescence: Associations with borderline personality disorder. Dev Psychopathol 2011;23(01):305-13.

74. Aggen S, Neale M, Roysamb E, Reichborn-Kjennerud T, Kendler K. A psychometric evaluation of the DSM-IV borderline personality disorder criteria: age and sex moderation of criterion functioning. Psychol Med 2009;39(12):1967.
75. Jane J, Oltmanns T, South S, Turkheimer E. Gender bias in diagnostic criteria for personality disorders: An item response theory analysis. J Abnorm Psychol 2007;116(1):166-75.
76. Nock M, Joiner T Jr, Gordon K, Lloyd-Richardson E, Prinstein M. Non-suicidal self-injury among adolescents: Diagnostic correlates and relation to suicide attempts. Psychiatry Res 2006;144(1):65-72.
77. Siever L, Torgersen S, Gunderson J, Livesley W, Kendler K. The borderline diagnosis III: identifying endophenotypes for genetic studies. Biol Psychiatry 2002;51:964-8.
78. Stanley B, Sher L, Wilson S, Ekman R, Huang Y, Mann J. Nonsuicidal self-injurious behavior, endogenous opioids and monoamine neurotransmitters. J Affect Disord 2010;124(1):134-40.
79. Sar V, Akyuz G, Kugu N, Ozturk E, Ertem-Vehid H. Axis I dissociative disorder comorbidity in borderline personality disorder and reports of childhood trauma. J Clin Psychiatry 2006;67(10):1583-90.
80. Stiglmayr C, Ebner-Priemer U, Bretz J, et al. Dissociative symptoms are positively related to stress in borderline personality disorder. Acta Psychiatr Scand 2008;117(2):139-47.
81. Stepp SD. Development of borderline personality disorder in adolescence and young adulthood: Introduction to the special section. J Abnorm Child Psychol 2012;40:1-5.
82. Burke JD, Stepp SD. Adolescent disruptive behavior and borderline personality disorder symptoms in young adult men. J Abnorm Child Psychol 2012;40(1):35-44.
83. Loeber R, Green SM, Lahey BB, Frick PJ, McBurnett K. Findings on disruptive behavior disorders from the first decade of the Developmental Trends Study. Clin Child Fam Psychol Rev 2000;3(1):37-60.
84. Stepp SD, Burke JD, Hipwell AE, Loeber R. Trajectories of attention deficit hyperactivity disorder and oppositional defiant disorder symptoms as precursors of borderline personality disorder symptoms in adolescent girls. J Abnorm Child Psychol 2012;40(1):7-20.
85. Helzer JE, Kraemer HC, Krueger RF. The feasibility and need for dimensional psychiatric diagnoses. Psychol Med 2006;36:1671-80.
86. Crick N, Murray-Close D, Woods K. Borderline personality features in childhood: A short-term longitudinal study. Dev Psychopathol 2005;17(04):1051-70.
87. Sharp C, Steinberg L, Temple J, Newlin E. An 11-item measure to assess borderline traits in adolescents: Refinement of the BPFSC using IRT. Personal Disord 2014;5(1):70-8.
88. Chanen AM, Jovev M, Djaja D, et al. Screening for borderline personality disorder in outpatient youth. J Pers Disord 2008:22(4):353-64.
89. Noblin J, Venta A, Sharp C. The validity of the MSI-BPD among inpatient adolescents. Assessment 2013;21:201-7.
90. Patel A, Sharp C, Fonagy P. Criterion validity of the MSI-BPD in a community sample of women. J Psychopathol Behav Assess 2011;33(3):403-8.
91. Sharp C, Bleiberg E. Borderline personality disorder in children and adolescents. In: Martin A and Volkmar F (eds). Lewis' child and adolescent psychiatry: Comprehensive textbook. Baltimore: Lippincott Williams and Wilkins; 2007; p. 680-91.
92. Zanarini MC, Vujanovic AA, Parachini EA, Boulanger JL, Frankenburg FR, Hennen J. A screening measure for BPD: the
20. McLean Screening Instrument for Borderline Personality Disorder (MSI-BPD). J Pers Disord 2003;17(6):568-73.
93. Poreh AM, Rawlings D, Claridge G, Freeman JL, Faulkner C, Shelton C. The BPQ: A scale for the assessment of borderline personality based on DSM-IV criteria. J Pers Disord 2006;20(3):247-60.
94. Chabrol H, Montovany A, Ducongé E, Kallmeyer A, Mullet E, Leichsenring F. Factor structure of the Borderline Personality Inventory in Adolescents. Eur J Psychol Assess 2004;20(1):59-65.
95. Leichsenring F. Development and first results of the Borderline Personality Inventory: A self-report instrument for assessing borderline personality organization. J Pers Assess 1999;73(1):45-63.
96. Morey L: The Personality Assessment Inventory professional manual. Lutz: Psychological Assessment Resources; 2007.
97. Millon T: Millon Adolescent Clinical Inventory. Minneapolis: National Computer Systems; 1993.
98. Millon T, Davis R. The Millon Adolescent Personality Inventory and the Millon Adolescent Clinical Inventory. J Counsel Devel 1993;71(5):570-4.
99. Sharp C, Mosko O, Chang B, Ha C. The cross-informant concordance and concurrent validity of the Borderline Personality Features Scale for Children in a sample of male youth. Clin Child Psychol Psychiatry 2011;16:335-49.
100. Krueger R, Eaton E. Personality traits and the classification of mental disorders: Toward a more complete integration in DSM-5 and an empirical model of psychopathology. Personal Disord 2010;1(2):97-118.
101. Skodol A. Scientific issues in the revision of personality disorders for DSM-5. Personal Ment Health 2011;5(2):97-111.
102. Stepp S, Burke J, Hipwell A, Loeber R. Trajectories of attention deficit hyperactivity disorder and oppositional defiant disorder symptoms as precursors of borderline personality disorder symptoms in adolescent girls. J Abnorm Child Psychology 2012;40(1):7-20.
103. Grant B, Chou S, Goldstein R, et al. Prevalence, correlates, disability, and comorbidity of DSM-IV borderline personality disorder: results from the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions. J Clin Psychiatry 2008;69(4):533-45.
104. Zanarini M, Frankenburg F, Vujanovic A, Hennen J, Reich D, Silk K. Axis II comorbidity of borderline personality disorder: description of 6-year course and prediction to time-to-remission. Acta Psychiatr Scand 2004;110(6):416-20.
105. Zanarini M, Frankenburg F, Hennen J, Reich D, Silk K. Prediction of the 10-year course of borderline personality disorder. Am J Psychiatry 2006;163(5):827-32.