Personality disorder overview

# Overview
Personality disorders (PD) are described as unique, long-term pervasive patterns of expressing and manifesting emotions, thoughts, and behaviors in an inflexible and maladaptive manner leading to significant functional impairment in one's life. Personality traits, in contrast, are specific patterns of thinking, perceiving, and responding to different situations in an adaptive and tenaciously stable way throughout life. The personality traits formulate an essential aspect in one's life in facing and dealing with contrasting situations as maladaptive personality can result in clinical distress and psychosocial impairment. In order to differentiate normal responses from abnormal or pathological, the criterion employed requires behaviors displayed by a majority in the population as normal and pathological if they are rare or there is the absence of a sense of contentment and adaptability to the social environment or marked deviation from cultural expectations. Hence, these are relative terms, and therefore, the Diagnostic and Statistical Manual of Mental Disorders (DSM) has established a set criterion for diagnosing personality disorders. This is based on the presence of impaired personality functioning and pathological traits. The pathophysiology of PD remains unclear to date. There are countless complex psychodynamic theories explaining the development of the disorder. Both genetic and environmental factors interplay in the causation of PD. A decrease in monoamine oxidase (MAO), and serotonin levels are seen with multiple PD. Although mostly recognized and diagnosed in adults, PD is present and develops in youth and adolescence. About 1 in 10 adolescents meets the criteria for PD. There are ten personality traits classified into 3 clusters; A, B, and C, based on similar characteristics. A clinical criterion as set by DSM-V is used for the diagnosis after the exclusion of other similar conditions (mental health disorder, substance use disorder, structural central nervous system (CNS) disorder). For most personality disorders, an age greater than 18 years is required for the diagnosis. This disorder is retained throughout an individual's life; however, certain types become less intense with age. The presence of PD is associated with increased mortality. The increased mortality is associated with unnatural causes like suicide, accidents, homicide, substance abuse, and depression. Natural death chances may also be enhanced in PD due to negative perspectives and emotions regarding health problems in life and the correlation of impaired mental health with physical health. Alcoholism and substance abuse contribute as precipitating factors and complications in PD. Psychotherapy remains the mainstay of treatment in both management and preventing complications. Medications are used as adjuncts. Cognitive-Behavioral therapy, impulse control, interpersonal psychotherapy, self-help groups, and family therapy are required. Medical therapy is required to balance and restore the neurotransmitter abnormalities associated with PD. Among them, Selective serotonin reuptake inhibitors (SSRIs) and newer antidepressants remain the hallmark. Antipsychotics and mood stabilizers also help. Despite individual and supportive psychotherapy, treatment of PD remains challenging and difficult.

# Historical Perspective
Personality defects were started to be recognized in the 18th century. Previously, all the diseases were a result of abnormalities with four bodily fluids; blood, phlegm, yellow bile, and black bile. The changes in them were also considered responsible for variations in mood. In the 18th century Phillippe Pinel described a group of people having impulsive, irrational ways and behaviors while maintaining understanding, perception, judgment, and memory of the actions. This was the birth of recognition of personality disorders. 
In the 19th century,Sigmund Freud, known as the father of psychology and his colleagues, worked on the psychoanalytic classification and etiology of personality. They related personality traits with childhood characters. He presented the structural theory that unconscious mental conflicts influence the development of character and behavior. In the late 1900s, statistics was utilized to group together different definitions of personality structures. It was pioneered by Bernard Cattell. This employs a different number of dimensions to delineate personality systems. These dimensional models lead to DSM characterization of personality disorders according to DSM classifications. DSM IV was established in 1994 with an updated version, DSM IV-TR, and uses a multiaxial approach to describe psychiatric illnesses with axis II reserved for personality disorder. This multiaxial system was abolished in DSM 5 and categorized the various disorders with related disorders.

# Classification
There are two approaches used to classify personality disorders; categorical and dimensional. Categorical classification is based on distinct operational criteria depending on behavioral characteristics. DSM-5 and ICD-10 both uses this approach. As compared to this, dimensional classification is based on the personality traits and using a quantitative distinction. It places normality at one end and disorder at other. DSM-5 classifies 10 personality disorders into three clusters due to similar characteristics:
CLUSTER A is defined as odd and eccentric and include Paranoid, Schizoid, and Schizotypal. CLUSTER B is defined by erratic and emotional behavior and includes Antisocial, Borderline, Histrionic and Narcissist. CLUSTER C PDs patients are anxious and fearful and incorporate Avoidant, Dependent and Obsessive-Compulsive. ICD-10 classifies into 3 clusters as well, which are A, Odd/eccentric and includesParanoid and Schizoid, B, Dramatic and includes , Emotionally unstable borderline type, Emotionally unstable impulsive type andHistrionic, and C, Anxious/fearful that include Anxious, Dependent and Anankastic.

# Pathophysiology
The exact pathogenesis of personality disorder is not fully understood. Personality disorders are related to multifactorial causes. Throughout time, a multitude of theories has been developed to explain the origin of these disorders. However still, the pathophysiology of PDs remains enigmatic. The five-factor model of personality was developed in the 1980s and 1990s, which demonstrated that it comprises five distinct traits. PDs are primarily the result of positive correlation with Neuroticism and negative association with Agreeableness. Extraversion is associated in both ways . It is a well-known fact that personality develops during childhood and interpersonal experiences and social interactions play a significant role in the development of PDs. Parental maltreatment, stress, and traumatic life events influence the personality adversely. In addition, genetic and prenatal factors also constitute a major role. Genetic factors with mutations in genes involving dopamine and serotonin pathways such as DRD2, COMT, DTNBP1, DAAO, 5-HTTLPR, MAOA, DRD3,TPH1 and TPH2 Perinatal injuries like trauma, infections like encephalitis, and hemorrhage may also be contributing factors. Genetic factors interact with environmental stresses to result in PDs. Various parental behavior like excessive attachment, parental insensitivity or emotional neglect, physical and sexual abuse, and substance use disorders causes an essential impact on PDs development. Social bullying, racial discrimination, frequent dislocations during childhood, and lack of peer support are other risk factors.

# Causes
Causative factors associated with PDs incorporate genetic factors with mutations in genes involving dopamine and serotonin pathways such as DRD2, COMT, DTNBP1, DAAO, 5-HTTLPR, MAOA, DRD3,TPH1 and TPH2; and environmental factors like stresses, parental treatment, sexual abuse and substance use.

# Differentiating Personality disorder from Other Diseases
Boderline disorder needs to be differentiated from mood disorders like Bipolar disorder, anxiety and delusional disorder.
Cluster-A disorders have to distinguished from delusional disorder (persecutory type), schizophreniform, bipolar disorder with psychotic symptoms and schizophrenia.
Post-traumatic stress disorder (PTSD) can also have interchangeable presenting complaints to the cluster-C PDs.. 
Thus, Axis-1 disorders and Axis-2 disorders have similar presentation and needs to be evaluated and ruled out before making the diagnosis of Axis-2 disorders.

# Epidemiology and Demographics
Worldwide pooled prevalence of personality disorder as found by meta-analysis of studies conducted from 21 countries is 7.8%. Global rates of cluster-A PD is 3.8%, cluster-B is 2.8% and cluster-C PD is 5%. In United States (US), it is around 10%, with major disease burden contributed by obsessive-compulsive PD followed by narcissist and borderline PD. In the rest of countries, it varies. OCD is twice common in females than males and 75% of individuals diagnosed with BPD are females. No sex predilection is found with rest. Narcissist PD is found in 20% of military personals, 17% first-year medical students and 6% forensic population.

# Risk Factors
The exact cause of personality disorder remains unknown. However, it usually results from the interplay of genetic and environmental factors. The risk of development of personality disorder is increased by the presence of certain factors such as perinatal injuries, family history, history of substance abuse, childhood abuse and other psychosocial factors.

# Screening
There is insufficient evidence to recommend routine screening for personality disorder. However, a few instruments are being employed to screen for personality disorders by family physicians particularly for BPD. This includes McLean Screening Instrument for Bipolar disorder. Rest are used for suicide-risk assessment and disease severity assessment.

# Natural History, Complications, and Prognosis
Personality disorders usually begin to develop in early adolescence and are diagnosed in early adulthood. The complications can occur at any stage and can add to a worsening prognosis. Suicidality is the most common complication. Others include injuries from fights and accidents, sexually acquired infections from presumptuous sex, and substance use disorder. It also adds to the morbidity by causing personal functional impairment and affecting family life. The mortality in PD is more than in the general population. The life expectancy in such individuals is influenced by psychotherapy initiation, treatment compliance, co-morbid conditions, and social support.

# Diagnosis

## Diagnostic Study of Choice
The diagnosis of personality disorder is intricate as most patients present with symptoms related to depression and anxiety, and many times, two or more personality disorders co-exist. Also, an overlap in certain personality characteristics among different personality disorders. Therefore, the diagnosis of a personality disorder requires a specific criterion after a complete evaluation of cognitive, behavioral, interpersonal, and social features in an individual. DSM-5 and ICD-10 criteria are usually employed for this purpose.

## History and Symptoms
History constitutes the first step in assessing for the personality disorder in any individual. The hallmark of personality disorders is an enduring and prolonged duration of presence of symptoms. An age of 18 years for a patient is essential in the diagnosis. The history varies with each type of personality disorder. Generally, a history of mood dysregulation and poor social interaction is suggestive of it.

## Physical Examination
There are no specific physical signs associated with personality disorders. The physical exam is essential to rule out organic disorders and substance use disorders. Depression and anxiety need to be ruled out by conducting their assessment tools. Patients with borderline personality disorders have an increased risk of suicide, and they may have self-inflicted wounds on the body or signs of attempted suicide attempts. A complete mental status examination needs to be conducted. The first is to examine appearance and behavior. Borderline personality disorder patients may exhibit defensive behavior. Those with a paranoid personality disorder will fail to maintain eye contact. The second is mood and affect; borderline personality disorder may reveal fleeting mood and emotional states with different questions or scenarios. This is also vital to assess suicide risk in the patient. Antisocial personality disorders may be homicidal and display a hostile attitude. Cognitive functions like attention, memory, orientation, language, and intelligence are normal. Mini-mental state examination (MMSE) can be conducted for this. Histrionic PD may manifest a  la belle indifference, meaning showing an apparent lack of concern regarding their own symptoms. Perception is normal though. Moreover, the thought process is usually unremarkable. It is imperative in paranoid personality disorder to ascertain that no thoughts of harm to others are present. However, insight and judgment may be affected depending on different scenarios in patients with variable personality disorders.

## Laboratory Findings
There are no diagnostic laboratory findings associated with personality disorders. Most laboratory tests are carried out to rule out other medical conditions which may present with personality changes. These tests include measurement of vitamin D, vitamin B12, ferritin, glucose and cortisol. PDs have concomitant substance abuse disorder and impulse control disorders. Hence, toxicology screen and sexually transmitted disease screening is crucial.

## Electrocardiogram
There is no role of electrocardiogram in PDs.

## X-ray
There are no specific X-ray changes associated with PDs.

## Echocardiography and Ultrasound
There is no use of echocardiography and ultrasound in diagnosis of Personality disorders.

## CT scan
There are no CT scan findings associated with personality disorder.

## MRI
The MRI changes observed in borderline PD are found in hypothalamus and limbic system. The volumetric changes in gray matter in various regions of brain are associated with rest of PDs.

## Other Imaging Findings
Positron emission tomography (PET) is another modality to assess the brain metabolism in different regions in different PDs. PET scan in BPD reveals hypometabolism of glucose in prefrontal cortex and limbic system

## Other Diagnostic Studies
Electroencephalographic (EEG) changes are observed in PD, however, they are not diagnostic. The presence of sharp and spike waves may be a common finding in BPD.

# Treatment
PD affects all aspects of individual life and causes interference with psychological and behavioral growth. It causes emotional distress and social impairment. It affects the quality of life grimly and has dire consequences on life years. Early recognition is crucial to start appropriate management and prevent complications from this debilitating condition. Management of PDs lacks evidence-based guidelines, and health authorities across the world have formulated their independent guidelines. American Society of Psychiatry guidelines exists only for BPD, while European guidelines are present for BPD, ASPD, and PD general. Family support and patient education play a vital role in effective management.

## Medical Therapy
No medical therapy is approved by Food and Drug administration, FDA for treatment of personality disorders. Pharmacotherapy is utilised to manage symptoms during acute decompensation and trait vulnerabilities. Mood dysregulatory symptoms are managed with (selective serotonin reuptake inhibitors) SSRIs or selective norepinephrine reuptake inhibitors (SNRIs) like venlafaxine. Mood stabilizers like lithium, valproate, carbamazepine, lamotrigine or topiramate are used as second line. Impulse behavioural dyscontrol symptoms are managed with SSRIs as first line and monoamine oxidase inhibitors (MAOIs) as second line. Cognitive perceptual symptoms are controlled with Low dose neuroleptics or antipsychotic medications.

## Interventions
Psychotherapy is the mainstay and core management for PDs. Psychodynamic psychotherapy (PDT) focuses on self-reflection and helps to deal with emotional and relational conflicts. Cognitive-behavioral therapy (CBT) is establishes emotional stability and behavioral regulation. It is used in ASPD, BPD, and substance use disorder. Dialectical-behavioral therapy is s subtype of CBT that reinforces and integrates positive emotions, thoughts, and behaviors by changing the negative thinking patterns. It is a significant therapy in cluster-B PDs. Interpersonal therapy comprises individual sessions that focus on improving interpersonal and social relationships. It is used for mood disorders and can be used in BPD. Dynamic Group psychotherapy brings out constructive and optimistic behaviors. European guidelines have the strongest recommendation for psychotherapy for BPD. Cognitive-behavioral therapy for ASPD is recommended by British and German guidelines. American society of Psychiatry recommends dialectical behavioral therapy and psychodynamic therapy for BPD.

## Surgery

## Primary Prevention

## Secondary Prevention