Other Specified Attention-Deficit/Hyperactivity Disorder 65
Personality disorders. In adolescents and adults, it may be difficult to distinguish ADHD
from borderline, narcissistic, and other person ality disorders. All these disorders tend to
share the features of disorganization, social  intrusiveness, emotional dysregulation, and
cognitive dysregulation. Howe ver, ADHD is not characterized by fear of abandonment,
self-injury, extreme ambivalence, or other fe atures of personality disorder. It may take
extended clinical observation, informant interview, or detailed history to distinguish im-
pulsive, socially intrusive, or inappropriate behavior from narcissist ic, aggressive, or dom-
ineering behavior to make this differential diagnosis.
Psychotic disorders. ADHD is not diagnosed if the symp toms of inattention and hyperac-
tivity occur exclusively during the course of a psychotic disorder.
Medication-induced symptoms of ADHD. Symptoms of inattention, hyperactivity, or
impulsivity attributable to the use of medication (e.g., bron chodilators, isoniazid, neuro-
leptics [resulting in akathisia], thyroid replacement medication) are diagnosed as other
specified or unspecified other (or un known) substance–related disorders.
Neurocognitive disorders. Early major neurocognitive disorder (dementia) and/or
mild neurocognitive disorder are not known to  be associated with ADHD but may present
with similar clinical features. These conditions are distinguished from ADHD by their late
onset.
Comorbidity
In clinical settings, comorbid  disorders are frequent in individuals whose symptoms meet
criteria for ADHD. In the general population, oppositional defiant di sorder co-occurs with
ADHD in approximately half of children wi th the combined presentation and about a
quarter with the predominantly inattentive presentation. Conduct disorder co-occurs in


quarter with the predominantly inattentive presentation. Conduct disorder co-occurs in
about a quarter of children or adolescents with the combined presentation, depending on
age and setting. Most children and adolescent s with disruptive mood dysregulation dis-
order have symptoms that also meet criteria  for ADHD; a lesser percentage of children
with ADHD have symptoms that meet criter ia for disruptive mood dysregulation disor-
der. Specific learning disorder commonly co-occurs with ADHD. Anxiety disorders and
major depressive disorder occur in a minority  of individuals with ADHD but more often
than in the general population. Intermittent explosive disorder occu rs in a minority of
adults with ADHD, but at rates above population levels. Although substance use disor-
ders are relatively more frequent among adul ts with ADHD in the general population, the
disorders are present in only a minority of adults with AD HD. In adults, antisocial and
other personality disorders may co-occur with ADHD. Other disorders that may co-occur
with ADHD include obsessive-compulsive diso rder, tic disorders, and autism spectrum
disorder.
Other Specified Attention-Deficit/
Hyperactivity Disorder
314.01 (F90.8)
This category applies to presentations in wh ich symptoms characteristic of attention-
deficit/hyperactivity disorder that cause clinic ally significant distress or impairment in so-
cial, occupational or other important areas of  functioning predominate but do not meet the
full criteria for attention-deficit/hyperactivity disorder or any of the disorders in the neuro-
developmental disorders diagnostic class. The other specified attention-deficit/hyperactiv-
ity disorder category is used in situations in which the clinician chooses to communicate


66 Neurodevelopmental Disorders
the specific reason that the presentation does not meet the criteria for attention-deficit/
hyperactivity disorder or any specific neur odevelopmental disorder. This is done by re-
cording “other specified attention-deficit/hyperactivity disorder” followed by the specific
reason (e.g., “with insufficient inattention symptoms”).
Unspecified Attention-Deficit/
Hyperactivity Disorder
314.01 (F90.9)
This category applies to presentations in wh ich symptoms characteristic of attention-
deficit/hyperactivity disorder that cause clinic ally significant distress or impairment in so-
cial, occupational, or other important areas of functioning predominate but do not meet the
full criteria for attention-deficit/hyperactivity disorder or any of the disorders in the neuro-
developmental disorders diagnostic class. The unspecified attention-deficit/hyperactivity
disorder category is used in situations in which the clinician chooses not to specify the rea-
son that the criteria are not met for attention- deficit/hyperactivity disorder or for a specific
neurodevelopmental disorder, and includes presentations in which there is insufficient in-
formation to make a more specific diagnosis.
Specific Learning Disorder
Specific Learning Disorder
Diagnostic Criteria
A. Difficulties learning and using academic skills,  as indicated by the presence of at least
one of the following symptoms that have persisted for at least 6 months, despite the
provision of interventions that target those difficulties:
1. Inaccurate or slow and effortful word reading (e.g., reads single words aloud incor-
rectly or slowly and hesitantly, frequently guesses words, has difficulty sounding
out words).
2. Difficulty understanding the meaning of what is read (e.g., may read text accurately
but not understand the sequence, relationships, inferences, or deeper meanings of
what is read).


what is read).
3. Difficulties with spelling (e.g., may add, omit, or substitute vowels or consonants).
4. Difficulties with written expression (e.g., makes multiple grammatical or punctua-
tion errors within sentences; employs poor paragraph organization; written expres-
sion of ideas lacks clarity).
5. Difficulties mastering number sense, number  facts, or calculation (e.g., has poor
understanding of numbers, their magnitude, and relationships; counts on fingers to
add single-digit numbers instead of recalling the math fact as peers do; gets lost in
the midst of arithmetic computation and may switch procedures).
6. Difficulties with mathematical reasoning (e.g., has severe difficulty applying math-
ematical concepts, facts, or procedures to solve quantitative problems).


Specific Learning Disorder 67
B. The affected academic skills are substantially and quantifiably below those expected
for the individual’s chronological age, and cause significant interference with academic
or occupational performance, or with activiti es of daily living, as confirmed by individu-
ally administered standardized achievement measures and comprehensive clinical
assessment. For individuals age 17 years and older, a documented history of impairing
learning difficulties may be substituted for the standardized assessment.
C. The learning difficulties begin during school-age years but may not become fully man-
ifest until the demands for those affected academic skills exceed the individual’s lim-
ited capacities (e.g., as in timed tests, reading or writing lengthy complex reports for a
tight deadline, excessively heavy academic loads).
D. The learning difficulties are not better accounted for by intellectual disabilities, uncor-
rected visual or auditory acuity, other mental or neurological disorders, psychosocial
adversity, lack of proficiency in the language of academic instruction, or inadequate
educational instruction.
Note:  The four diagnostic criteria are to be met based on a clinical synthesis of the indi-
vidual’s history (developmental, medical, fa mily, educational), school reports, and psycho-
educational assessment.
Coding note:  Specify all academic domains and subskills that are impaired. When more
than one domain is impaired, each one should be coded individually according to the fol-
lowing specifiers.
Specify if:
315.00 (F81.0) With impairment in reading:
Word reading accuracy
Reading rate or fluency
Reading comprehension
Note:  Dyslexia  is an alternative term used to refer to a pattern of learning difficulties
characterized by problems with accurate or fluent word recognition, poor decoding,
and poor spelling abilities. If dyslexia is used to specify this particular pattern of dif-


and poor spelling abilities. If dyslexia is used to specify this particular pattern of dif-
ficulties, it is important also to specify any additional difficulties that are present,
such as difficulties with reading comprehension or math reasoning.
315.2 (F81.81) With impairme nt in written expression:
Spelling accuracy
Grammar and punctuation accuracy
Clarity or organization of written expression
315.1 (F81.2) With impairment in mathematics:
Number sense
Memorization of arithmetic facts
Accurate or fluent calculation
Accurate math reasoning
Note:  Dyscalculia  is an alternative term used to refer to a pattern of difficulties char-
acterized by problems processing numerical information, learning arithmetic facts,
and performing accurate or fluent calculations. If dyscalculia is used to specify this
particular pattern of mathematic difficulties, it is important also to specify any addi-
tional difficulties that are present, such as difficulties with math reasoning or word rea-
soning accuracy.
Specify current severity:
Mild:  Some difficulties learning skills in one or two academic domains, but of mild enough
severity that the individual may be able to compensate or function well when provided with
appropriate accommodations or support services, especially during the school years.


68 Neurodevelopmental Disorders
Moderate: Marked difficulties learning skills in one or more academic domains, so that
the individual is unlikely to become proficient without some intervals of intensive and
specialized teaching during the school years. Some accommodations or supportive
services at least part of the day at school, in the workplace, or at home may be needed
to complete activities accurately and efficiently.
Severe:  Severe difficulties learning skills, affecting several academic domains, so that
the individual is unlikely to learn those skills without ongoing intensive individualized
and specialized teaching for most of the school years. Even with an array of appropri-
ate accommodations or services at home, at school, or in the workplace, the individual
may not be able to complete all activities efficiently.
Recording Procedures
Each impaired academic domain and subskill of specific learning disorder should be re-
corded. Because of ICD coding requirements, im pairments in reading, impairments in writ-
ten expression, and impairments in mathematics, with their corresponding impairments in
subskills, must be coded sepa rately. For example, impairments in reading and mathematics
and impairments in the subskills of reading rate or fluency, reading comprehension, accu-
rate or fluent calculation, and accurate math reasoning would be coded and recorded as
315.00 (F81.0) specific learning disorder with impairment in reading, with impairment in
reading rate or fluency and impairment in reading comprehension; 315.1 (F81.2) specific
learning disorder with impairment in mathemat ics, with impairment in accurate or fluent
calculation and impairment in  accurate math reasoning.
Diagnostic Features
Specific learning disorder is a neurodevelopmental  disorder with a biological origin that is
the basis for abnormalities at a cognitive level that are associated with the behavioral signs


the basis for abnormalities at a cognitive level that are associated with the behavioral signs
of the disorder. The biological origin includes an interaction of geneti c, epigenetic, and en-
vironmental factors, which affect the brain’s ab ility to perceive or process verbal or non-
verbal information efficiently and accurately.
One essential feature of specific learning diso rder is persistent diff iculties learning key-
stone academic skills (Criterion A), with onset duri ng the years of formal schooling (i.e., the de-
velopmental period). Key academic skills incl ude reading of single words accurately and
fluently, reading comprehension,  written expression and spelling, arithmetic calculation, and
mathematical reasoning (solving mathematical problems). In contrast to talking or walking,
which are acquired developmenta l milestones that emerge wi th brain maturation, academic
skills (e.g., reading, spelling, writing, mathematic s) have to be taught and learned explicitly.
Specific learning disorder disrupts the normal pa ttern of learning academ ic skills; it is not sim-
ply a consequence of lack of o pportunity of learning or inadeq uate instruction. Difficulties
mastering these key academic skills may also impe de learning in other academic subjects (e.g.,
history, science, social studies) , but those problems are attributable to difficulties learning the
underlying academic skills. Difficulties learning  to map letters with the sounds of one’s lan-
guage—to read printed words (often called dyslexia)—is one of the most common manifesta-
tions of specific learning disord er. The learning difficulties manifest as a range of observable,
descriptive behaviors or symptoms (as listed in Criteria A1–A6). These clinical symptoms may
be observed, probed by means of the clinical interview, or ascert ained from school reports, rat-


ing scales, or descriptions in previous educational or psychological assessments. The learning
difficulties are persistent, not transitory. In ch ildren and adolescents, persistence  is defined as
restricted progress in learning (i.e., no evidence that the individual is catching up with class-


difficulties are persistent, not transitory. In ch ildren and adolescents, persistence  is defined as
restricted progress in learning (i.e., no evidence that the individual is catching up with class-
mates) for at least 6 months despite the provision of extra help at home or school. For example,
difficulties learning to read si ngle words that do not fully or rapidly remit with the provision of
instruction in phonological skills or word iden tification strategies may indicate a specific


Specific Learning Disorder 69
learning disorder. Evidence of persistent learning difficulties  may be derived from cumulative
school reports, portfolios of the child’s evalua ted work, curriculum-based measures, or clinical
interview. In adults, persistent difficulty refers  to ongoing difficulties in literacy or numeracy
skills that manifest during childhood or adol escence, as indicated by cumulative evidence
from school reports, evaluated portfo lios of work, or previous assessments.
A second key feature is that the individual’s performance of the affected academic skills is
well below average for age (Criterion B). One robust clinical indicator of difficulties learning
academic skills is low academic achievement for age or average achievement that is sustain-
able only by extraordinarily high levels of effort  or support. In children, the low academic skills
cause significant interference in school performance (as indicated by school reports and
teacher’s grades or ratings). Another clinical indicator, particularly in adults, is avoidance of
activities that require the academic skills. Also in adulthood, low academic  skills interfere with
occupational performance or everyday activities  requiring those skills (as indicated by self-re-
port or report by others). However, this criterion also requires psycho metric evidence from an
individually administered, psychometrically s ound and culturally appropriate test of aca-
demic achievement that is norm -referenced or criter ion-referenced. Academic skills are dis-
tributed along a continuum, so there is no natural cutpoint that can be used to differentiate
individuals with and without spec ific learning disorder. Thus, any threshold used to specify
what constitutes significantly low academic achi evement (e.g., academic skills well below age
expectation) is to a large extent arbitrary. Lo w achievement scores on one or more standard-
ized tests or subtests within an academic domain (i.e., at least 1.5 standard deviations [SD] be-


low the population mean for age, which translates to a standard score of 78 or less, which is
below the 7th percentile) are need ed for the greatest diagnostic certainty. However, precise
scores will vary according to the particular standardized tests that are used. On the basis of
clinical judgment, a more leni ent threshold may be used (e.g., 1.0–2.5 SD below the pop-
ulation mean for age), when learning diffic ulties are supported by  converging evidence
from clinical assessment, academic history, school reports, or test  scores. Moreover, since
standardized tests are not available in all languages, the diagnosis may then be based in
part on clinical judgment of sc ores on available test measures.
A third core feature is that the learning di fficulties are readily apparent in the early
school years in most individuals (Criterion C) . However, in others, the learning difficulties
may not manifest fully until later school year s, by which time learning demands have in-
creased and exceed the individual’s limited capacities.
Another key diagnostic feature is that the learning difficulties  are considered “spe-
cific,” for four reasons. First, they are not attr ibutable to intellectual disabilities (intellec-
tual disability [intellectual developmenta l disorder]); global developmental delay;
hearing or vision disorders, or neurological or motor disorders) (Criterion D). Specific
learning disorder affects lear ning in individuals who othe rwise demonstrate normal lev-
els of intellectual functioning (generally estima ted by an IQ score of greater than about 70
[±5 points allowing for measurement error ]). The phrase “unexpected academic under-
achievement” is often cited as the defining ch aracteristic of specific learning disorder in
that the specific learning disabilities are not part of a more general learning difficulty as


that the specific learning disabilities are not part of a more general learning difficulty as
manifested in intellectual disability or global developmental delay. Specific learning dis-


that the specific learning disabilities are not part of a more general learning difficulty as
manifested in intellectual disability or global developmental delay. Specific learning dis-
order may also occur in individuals identified  as intellectually “gifted.” These individuals
may be able to sustain apparently adequate  academic functioning by using compensatory
strategies, extraordinarily high effort, or su pport, until the learning demands or assess-
ment procedures (e.g., timed tests) pose barri ers to their demonstrating their learning or
accomplishing required tasks. Second, the lear ning difficulty cannot be  attributed to more
general external factors, such as economic or environmental disadvantage, chronic absen-
teeism, or lack of education as typically prov ided in the individual’s community context.
Third, the learning difficulty canno t be attributed to a neurol ogical (e.g., pediatric stroke)
or motor disorders or to vision or hearing di sorders, which are often associated with prob-
lems learning academic skills but are distinguishable by presence of neurological signs.


70 Neurodevelopmental Disorders
Finally, the learning difficulty may be restricted to one academic skill or domain (e.g., read-
ing single words, retrieving or  calculating number facts).
Comprehensive assessment is required. Specifi c learning disorder can only be diagnosed
after formal education starts bu t can be diagnosed at any point afterward in children, adoles-
cents, or adults, providing there is evidence of onset during the years of formal schooling (i.e.,
the developmental period). No sing le data source is sufficient fo r a diagnosis of specific learn-
ing disorder. Rather, specific learning disorder is a clinical diagnosis based on a synthesis of
the individual’s medical, develo pmental, educational, and family  history; the history of the
learning difficulty, including it s previous and current manifestat ion; the impact of the diffi-
culty on academic, occupational, or social functioning; previo us or current school reports;
portfolios of work requiring academic skills; curriculum-based assessments; and previous or
current scores from individual standardized test s of academic achievemen t. If an intellectual,
sensory, neurological, or motor disorder is susp ected, then the clinical assessment for specific
learning disorder should also include methods appropriate for these disorders. Thus, compre-
hensive assessment will involve professionals with expertise in specific learning disorder and
psychological/cognitive assessment. Since specific  learning disorder typically persists into
adulthood, reassessment is rarely necessary, un less indicated by marked changes in the learn-
ing difficulties (amelioration or worsenin g) or requested for specific purposes.
Associated Features Supporting Diagnosis
Specific learning disorder is frequently but not invariably preceded, in preschool years, by
delays in attention, language, or motor skills that may pers ist and co-occur with specific
learning disorder. An uneven profile of abilities is common , such as above-average abili-


learning disorder. An uneven profile of abilities is common , such as above-average abili-
ties in drawing, design, and other visuospatial  abilities, but slow, effortful, and inaccurate
reading and poor reading comprehension and written expression. Individuals with spe-
cific learning disorder typica lly (but not invariably) exhibit poor performance on psycho-
logical tests of cognitive processing. However,  it remains unclear whether these cognitive
abnormalities are the caus e, correlate, or consequence of th e learning difficulties. Also, al-
though cognitive deficits associated with diff iculties learning to read words are well doc-
umented, those associated with other manifestations of specific learning disorder (e.g.,
reading comprehension, arithmetic computat ion, written expression) are underspecified
or unknown. Moreover, individu als with similar behavioral sy mptoms or test scores are
found to have a variety of cognitive deficits, and many of these processing deficits are also
found in other neurodevelopmental disorders (e.g., attention-deficit/hyperactivity disor-
der [ADHD], autistic spectrum  disorder, communication diso rders, developmental coor-
dination disorder). Thus, asses sment of cognitive processing deficits is not required for
diagnostic assessment. Specific le arning disorder is associated  with increased risk for sui-
cidal ideation and suicide attempts in  children, adolescents, and adults.
There are no known biological markers of spec ific learning disorder. As a group, indi-
viduals with the disorder show circumscribe d alterations in cognitive processing and
brain structure and func tion. Genetic differences are also evident at the group level. But
cognitive testing, neuroimaging, or genetic test ing are not useful for diagnosis at this time.
Prevalence
The prevalence of specific learning disorder across the academic domains of reading, writ-


Prevalence
The prevalence of specific learning disorder across the academic domains of reading, writ-
ing, and mathematics is 5%–15% among school-age children across different languages
and cultures. Prevalence in adults is unknown but appear s to be approximately 4%.


ing, and mathematics is 5%–15% among school-age children across different languages
and cultures. Prevalence in adults is unknown but appear s to be approximately 4%.
Development and Course
Onset, recognition, and diagnosis of specific learning disorder usually occurs during the
elementary school years when children are requir ed to learn to read, sp ell, write, and learn


Specific Learning Disorder 71
mathematics. However, precursors such as la nguage delays or defi cits, difficulties in
rhyming or counting, or difficulties with fine motor skills required  for writing commonly
occur in early childhood before the start of formal schooling. Manifestations may be be-
havioral (e.g., a reluctance to engage in le arning; oppositional beha vior). Specific learning
disorder is lifelong, but the course and clinical expression are variable, in part depending
on the interactions among the task demands of  the environment, the range and severity of
the individual’s learning difficulties, the indi vidual’s learning abilities, comorbidity, and
the available support systems and intervention . Nonetheless, problems with reading flu-
ency and comprehension, spelling, written expr ession, and numeracy sk ills in everyday life
typically persist into adulthood.
Changes in manifestation of symptoms occur with age, so that an individual may have
a persistent or shifting array of learning difficulties across the lifespan.
Examples of symptoms that may be observed among preschool-age children include a lack
of interest in playing games with language s ounds (e.g., repetition, rhyming), and they may
have trouble learning nursery rhymes. Preschool children with sp ecific learning disorder may
frequently use baby talk, mispronounce words,  and have trouble remembering names of let-
ters, numbers, or days of the week. They may fa il to recognize letters in their own names and
have trouble learning to count. Kindergarten-age children with specific learning disorder may
be unable to recognize and write letters, may be unable to write their own names, or may use
invented spelling. They may have trouble brea king down spoken words into syllables (e.g.,


“cowboy” into “cow” and “boy”) and trouble reco gnizing words that rhyme (e.g., cat, bat, hat).
Kindergarten-age children also may have trouble connecting letters with their sounds (e.g., let-
ter b makes the sound /b/) and may be unable  to recognize phonemes (e.g., do not know
which in a set of words [e.g., dog, man, car] starts with the same sound as “cat”).
Specific learning disorder in elementary school–age children typically manifests as
marked difficulty learning letter-sound corres pondence (particularly in English-speaking
children), fluent word decoding, spelling, or ma th facts; reading aloud is slow, inaccurate,
and effortful, and some childr en struggle to understand the magnitude that a spoken or
written number represents. Children in prim ary grades (grades 1–3) may continue to have
problems recognizing and manipulating phon emes, be unable to read common one-sylla-
ble words (such as mat or top), and be un able recognize common irregularly spelled
words (e.g., said, two). They may commit read ing errors that indicate problems in con-
necting sounds and letters (e.g., “big” for “g ot”) and have difficult y sequencing numbers
and letters. Children in grades 1-3 also may have difficulty remembering number facts or
arithmetic procedures for addi ng, subtracting, and so forth, and may complain that read-
ing or arithmetic is hard and avoid doing it. Ch ildren with specific learning disorder in the
middle grades (grades 4–6) may mispronounce or skip parts of long, multisyllable words
(e.g., say “conible” for “convertible,” “aminal” for “animal”) and confuse words that


sound alike (e.g., “tornado” for “volcano”) . They may have trouble remembering dates,
names, and telephone numbers and may have trouble completing homework or tests on
time. Children in the middle grades also may have poor comprehension with or without
slow, effortful, and inaccurate reading, and they may have trouble reading small function
words (e.g., that, the, an, in). They may ha ve very poor spelling and poor written work.
They may get the first part of a word correctly , then guess wildly (e.g., read “clover” as
“clock”), and may express fear of read ing aloud or refuse to read aloud.


They may get the first part of a word correctly , then guess wildly (e.g., read “clover” as
“clock”), and may express fear of read ing aloud or refuse to read aloud.
By contrast, adolescents may have mastered  word decoding, but reading remains slow
and effortful, and they are likely to show ma rked problems in reading comprehension and
written expression (including poor spelling) and poor master y of math facts or mathemat-
ical problem solving. During adolescence an d into adulthood, indi viduals with specific
learning disorder may continue to make nu merous  spelling mistakes and read single
words and connected text slowly and with mu ch effort, with trou ble pronouncing multi-
syllable words. They may frequently need to reread material to understand or get the main
point and have trouble making inferences fr om written text. Adolescents and adults may


72 Neurodevelopmental Disorders
avoid activities that demand reading or arit hmetic (reading for pl easure, reading instruc-
tions). Adults with specific learning disord er have ongoing spelling problems, slow and
effortful reading, or problems making impo rtant inferences from numerical information
in work-related written documents. They ma y avoid both leisure and work-related activ-
ities that demand reading or writing or use alternative approaches to access print (e.g.,
text-to-speech/speech-to-text softwa re, audiobooks, audiovisual media).
An alternative clinical expression is that of  circumscribed learning difficulties that per-
sist across the lifespan, such as an inability to master the basic sense of number (e.g., to
know which of a pair of number s or dots represents the larger magnitude), or lack of pro-
ficiency in word identification or spelling. Av oidance of or reluctance to engage in activi-
ties requiring academic skills is common in ch ildren, adolescents, and adults. Episodes of
severe anxiety or anxiety disorders, including somatic complaints or panic attacks, are
common across the lifespan and accompany both the circumscribed and the broader ex-
pression of learning difficulties.
Risk and Prognostic Factors
Environmental. Prematurity or very low birth weight increases the risk for specific
learning disorder, as does pr enatal exposure to nicotine.
Genetic and physiological. Specific learning disorder a ppears to aggregate in families,
particularly when affecting reading, mathemat ics, and spelling. The relative risk of spe-
cific learning disorder in reading or mathematics is substantially higher (e.g., 4–8 times
and 5–10 times higher, respectively) in first- degree relatives of individuals with these
learning difficulties compared with those wi thout them. Family hist ory of reading diffi-


learning difficulties compared with those wi thout them. Family hist ory of reading diffi-
culties (dyslexia) and parental literacy skills predict literacy problems or specific learning
disorder in offspring, indicating the combin ed role of genetic and environmental factors.
There is high heritability for both reading ab ility and reading disability in alphabetic and
nonalphabetic languages, including high heritabi lity for most manifestations of learning abil-
ities and disabilities (e.g., heritability estimate  values greater than 0. 6). Covariation between
various manifestations of learning difficulties is high, suggesting that genes related to one
presentation are highly co rrelated with genes related to another manifestation.
Course modifiers. Marked problems with inattentive be havior in preschool years is pre-
dictive of later difficulties in reading and ma thematics (but not necessarily specific learn-
ing disorder) and nonresponse to  effective academic interventions. Delay or disorders in
speech or language, or impaired cognitive processing (e.g., phonological awareness,
working memory, rapid serial naming) in presch ool years, predicts la ter specific learning
disorder in reading and writ ten expression. Comorbidity wi th ADHD is predictive of
worse mental health outcome than that associ ated with specific learning disorder without
ADHD. Systematic, intensive, individualized instruction, using evidence-based interven-
tions, may improve or ameliorate the learning difficulties in some individuals or promote
the use of compensatory strategies in others , thereby mitigating the otherwise poor out-
comes.
Culture-Related Diagnostic Issues
Specific learning disorder oc curs across languages, cultures, races, and socioeconomic
conditions but may vary in its manifestation according to the nature of the spoken and
written symbol systems and cultural and educational practices. For example, the cognitive


written symbol systems and cultural and educational practices. For example, the cognitive
processing requirements of reading and of wo rking with numbers vary greatly across or-
thographies. In the English language, the observable hallmark clinical symptom of diffi-
culties learning to read is inaccurate and slow reading of single words; in other alphabetic


thographies. In the English language, the observable hallmark clinical symptom of diffi-
culties learning to read is inaccurate and slow reading of single words; in other alphabetic
languages that have more direct mapping be tween sounds and letters (e.g., Spanish, Ger-
man) and in non-alphabetic la nguages (e.g., Chinese, Japanese), the hallmark feature is


Specific Learning Disorder 73
slow but accurate reading. In English-language learners, assessment should include con-
sideration of whether the source of reading difficulties is a limited proficiency with Eng-
lish or a specific learning disorder. Risk fact ors for specific learning  disorder in English-
language learners include a family history of specific learning disorder or language delay
in the native language, as well as learning difficulties in English and failure to catch up
with peers. If there is suspicio n of cultural or language differences (e.g., as in an English-
language learner), the assessment needs to ta ke into account the individual’s language
proficiency in his or her first or native lang uage as well as in the second language (in this
example, English). Also, assessment should co nsider the linguistic and cultural context in
which the individual is living, as well as his or  her educational and learning history in the
original culture and language.
Gender-Related Diagnostic Issues
Specific learning disorder is more common in males than in fema les (ratios range from
about 2:1 to 3:1) and cannot be attributed to factors such as ascertainment bias, definitional
or measurement variation, language , race, or socioeconomic status.
Functional Consequences of
Specific Learning Disorder
Specific learning disorder can have negative functional consequences across the lifespan,
including lower academic attainment, higher ra tes of high school dropout, lower rates of
postsecondary education, high levels of psyc hological distress and poorer overall mental
health, higher rates of unemployment and under-employment, and lower incomes. School
dropout and co-occurring depressive symptoms increase the risk for poor mental health
outcomes, including suicidality, whereas high levels of social or emotional support predict
better mental health outcomes.
Differential Diagnosis
Normal variations in academic attainment. Specific learning disorder is distinguished


Differential Diagnosis
Normal variations in academic attainment. Specific learning disorder is distinguished
from normal variations in academic attainment due to external factors (e.g., lack of edu-
cational opportunity, consistently poor instru ction, learning in a second language), be-
cause the learning difficulties persist in the presence of adequate educational opportunity
and exposure to the same instruction as the p eer group, and competency in the language of
instruction, even when it is different  from one’s primary spoken language.
Intellectual disability (intelle ctual developmental disorder). Specific learning disorder
differs from general learning difficulties assoc iated with intellectual  disability, because the
learning difficulties occur in the presence of normal levels of intellectual functioning (i.e.,
IQ score of at least 70 ± 5). If intellectual disa bility is present, specific learning disorder can
be diagnosed only when the learning difficult ies are in excess of those usually associated
with the intellectual disability.
Learning difficulties due to neurological or sensory disorders. Specific learning dis-
order is distinguished from lear ning difficulties due to neurological or sensory disorders
(e.g., pediatric stroke, traumatic brain injury , hearing impairment, vi sion impairment), be-
cause in these cases there are abnormal findings on neurological examination.
Neurocognitive disorders. Specific learning disorder is distinguished from learning
problems associated with neurodegenerative cognitive disorders, because in specific
learning disorder the clinical expression of specific learning difficulties occurs during the
developmental period, and the difficulties do not manifest as a mark ed decline from a for-
mer state.


74 Neurodevelopmental Disorders
Attention-deficit/hyperactivity disorder. Specific learning disorder is distinguished from
the poor academic performance associated with ADHD, because in the latter condition the
problems may not necessarily reflect specific difficulties in learning academic skills but
rather may reflect difficulties in performing  those skills. However,  the co-occurrence of
specific learning disorder and ADHD is more fr equent than expected by chance. If criteria
for both disorders are met, both diagnoses can be given.
Psychotic disorders. Specific learning disorder is dist inguished from the academic and
cognitive-processing difficulties associated wi th schizophrenia or psychosis, because with
these disorders there is a decline (often rapid) in these functional domains.
Comorbidity
Specific learning disorder commonly co-occ urs with neurodevelopmental (e.g., ADHD,
communication disorders, developmental coordi nation disorder, autistic spectrum disor-
der) or other mental disorders (e.g., anxiety disorders, depressive and bipolar disorders).
These comorbidities do not necessarily exclud e the diagnosis specific learning disorder
but may make testing and differential diagnosis more difficult, because each of the co-
occurring disorders independentl y interferes with the executio n of activities of daily liv-
ing, including learning. Thus, clinical judgment  is required to attrib ute such impairment to
learning difficulties. If there is an indication that another diagnosis could account for the
difficulties learning keystone academic skills  described in Criterion A, specific learning
disorder should not be diagnosed.
Motor Disorders
Developmental Coordination Disorder
Diagnostic Criteria 315.4 (F82)
A. The acquisition and execution of coordinated motor skills is substantially below that ex-
pected given the individual’s chronological age and opportunity for skill learning and
use. Difficulties are manifested as clumsi ness (e.g., dropping or bumping into objects)


as well as slowness and inaccuracy of performance of motor skills (e.g., catching an
object, using scissors or cutlery, handwriting, riding a bike, or participating in sports).
B. The motor skills deficit in Criterion A significantly and persistently interferes with activ-
ities of daily living appropriate to chronological age (e.g., self-care and self-mainte-
nance) and impacts academic/school pr oductivity, prevocational and vocational
activities, leisure, and play.
C. Onset of symptoms is in the early developmental period.
D. The motor skills deficits are not better explained by intellectual disability (intellectual devel-
opmental disorder) or visual impairment and are not attributable to a neurological condi-
tion affecting movement (e.g., cerebral palsy, muscular dystrophy, degenerative disorder).
Diagnostic Features
The diagnosis of developmental coordination diso rder is made by a clinical synthesis of the
history (developmental and medical), physical ex amination, school or workplace report, and
individual assessment using psychometrically sound and culturally appropriate standardized
tests. The manifestation of impaired skills re quiring motor coordination  (Criterion A) varies


Developmental Coordination Disorder 75
with age. Young children may be delayed in achi eving motor milestones (i.e., sitting, crawling,
walking), although many achieve typical motor milestones. They also may be delayed in de-
veloping skills such as negotiating stairs, peda ling, buttoning shirts, completing puzzles, and
using zippers. Even when the skill is achiev ed, movement executio n may appear awkward,
slow, or less precise than that of  peers. Older children and adults may display slow speed or in-
accuracy with motor aspects of activities such as assembling puzzles, building models, playing
ball games (especially in teams), handwriting, ty ping, driving, or carrying out self-care skills.
Developmental coordination di sorder is diagnosed only if  the impairment in motor
skills significantly interferes with the performanc e of, or participation in, daily activities in
family, social, school, or community life (Criteri on B). Examples of such activities include
getting dressed, eating meals with age-appropriate utensils and without mess, engaging
in physical games with others, using specific t ools in class such as rulers and scissors, and
participating in team exercise activities at sc hool. Not only is ability to perform these ac-
tions impaired, but also marked slowness in execution is common. Handwriting compe-
tence is frequently affected, consequently affe cting legibility and/or speed of written output
and affecting academic achievement (the impact is distinguished from specific learning
difficulty by the emphasis on the motoric comp onent of written output skills). In adults,
everyday skills in education and work, especially those in which speed and accuracy are
required, are affected by coordination problems.
Criterion C states that the onset of sympto ms of developmental coordination disorder
must be in the early developmental period. However, developmental coordination disorder is


must be in the early developmental period. However, developmental coordination disorder is
typically not diagnosed before age 5 years because there is considerable variation in the age at
acquisition of many motor skills or a lack of st ability of measurement in early childhood (e.g.,
some children catch up) or because other causes of motor delay may not have fully manifested.
Criterion D specifies that the diagnosis of  developmental coordination disorder is
made if the coordination difficulties are not better explained by visual impairment or at-
tributable to a neurological condition. Thus, visual functi on examination and neurological
examination must be included in the diagnost ic evaluation. If intellectual disability (intel-
lectual developmental disorder) is present, the motor difficulties are in excess of those ex-
pected for the mental age; ho wever, no IQ cut-off or disc repancy criterion is specified.
Developmental coordination disorder does no t have discrete subtypes; however, indi-
viduals may be impaired predominantly in gro ss motor skills or in fine motor skills, in-
cluding handwriting skills.
Other terms used to describe developm ental coordination disorder include childhood
dyspraxia,  specific developmental disorder of motor function,  and clumsy child syndrome.
Associated Features Supporting Diagnosis
Some children with developmental coordination disorder sh ow additional (usually sup-
pressed) motor activity, such as choreiform  movements of unsupported limbs or mirror
movements. These “overflow” movements are referred to as neurodevelopment al immaturities  or
neurological soft signs  rather than neurological abnormalit ies. In both current literature and
clinical practice, their role in diagnosis is  still unclear, requiring further evaluation.
Prevalence
The prevalence of developmental coordination disorder in children ages 5–11 years is 5%–
6% (in children age 7 years, 1.8% are diagnosed with severe developmental coordination


disorder and 3% with probable developmental coordination disorder). Males are more of-
ten affected than females, with a male:female ratio between 2:1 and 7:1.


disorder and 3% with probable developmental coordination disorder). Males are more of-
ten affected than females, with a male:female ratio between 2:1 and 7:1.
Development and Course
The course of developmental coordination disord er is variable but stable at least to 1 year
follow-up. Although there may be improvement in the longer term, problems with coor-


76 Neurodevelopmental Disorders
dinated movements continue th rough adolescence in an esti mated 50%–70% of children.
Onset is in early childhood. Delayed motor mile stones may be the first signs, or the disor-
der is first recognized when the child attempts  tasks such as holding a knife and fork, but-
toning clothes, or playing ball games. In middle childhood, there are difficulties with
motor aspects of assembling puzzles, building  models, playing ball, and handwriting, as
well as with organizing belongings, when mo tor sequencing and co ordination are re-
quired. In early adulthood, there is continuing difficulty in learning new tasks involving
complex/automatic motor skills, including drivin g and using tools. Inability to take notes
and handwrite quickly may affect performance in the workplace. Co-occurrence with
other disorders (see the sectio n “Comorbidity” for this disorder) has an additional impact
on presentation, course, and outcome.
Risk and Prognostic Factors
Environmental. Developmental coordination disorder  is more common following pre-
natal exposure to alcohol and in pr eterm and low-birth-weight children.
Genetic and physiological. Impairments in underlying neurodevelopmental processes—
particularly in visual-motor sk ills, both in visual-motor perception and spatial mentalizing—
have been found and affect the ability to make rapid motoric adjustments as the complexity of
the required movements increases. Cerebellar dysfunction has been proposed, but the neural
basis of developmental coordination disorder remains unclear. Because of the co-occurrence of
developmental coordination disorder with atte ntion-deficit/hyperactiv ity disorder (ADHD),
specific learning disabilities, and autism spectr um disorder, shared genetic effect has been pro-
posed. However, consistent co-occurrence in twins appears only in severe cases.


posed. However, consistent co-occurrence in twins appears only in severe cases.
Course modifiers. Individuals with ADHD and with developmental coordination dis-
order demonstrate more impair ment than individuals with  ADHD without developmen-
tal coordination disorder.
Culture-Related Diagnostic Issues
Developmental coordination disorder occurs  across cultures, races, and socioeconomic
conditions. By definition, “acti vities of daily living” implie s cultural differences necessi-
tating consideration of the context in whic h the individual child is living as well as
whether he or she has had appropriate opportun ities to learn and practice such activities.
Functional Consequences of
Developmental Coordination Disorder
Developmental coordination disorder leads to  impaired functional performance in activ-
ities of daily living (Criterion B), and the impairment is increased with co-occurring con-
ditions. Consequences of developmental coordination disorder include reduced
participation in team play and sports; poor self-esteem and sense of self-worth ; emotional
or behavior problems; impair ed academic achievement; p oor physical fitness; and re-
duced physical activity and obesity.
Differential Diagnosis
Motor impairments due to another medical condition. Problems in coordination may
be associated with visual function impairme nt and specific neurological disorders (e.g.,
cerebral palsy, progressive lesions of the cerebellum, neuromuscula r disorders). In such
cases, there are additional findin gs on neurological examination.
Intellectual disability (intell ectual developmental disorder). If intellectual disability is
present, motor competences may be impaired in accordance with the intellectual disabil-


Stereotypic Movement Disorder 77
ity. However, if the motor difficulties are in excess of what could be  accounted for by the
intellectual disability, and crit eria for developmental coordination disorder are met, de-
velopmental coordination disorder can be diagnosed as well.
Attention-deficit/hyperactivity disorder. Individuals with ADHD may fall, bump into
objects, or knock things over. Careful observat ion across different contexts is required to
ascertain if lack of motor competence is at tributable to distract ibility and impulsiveness
rather than to developmental coordination disorder. If criteria for both ADHD and devel-
opmental coordination disorder are met, both diagnoses can be given.
Autism spectrum disorder. Individuals with autism spectrum disorder may be uninter-
ested in participating in task s requiring complex coordination skills, such as ball sports,
which will affect test performance and function but not reflect core motor competence. Co-
occurrence of developmental coordination disorder and autism spectr um disorder is com-
mon. If criteria for both  disorders are met, both diagnoses can be given.
Joint hypermobility syndrome. Individuals with syndrome s causing hyperextensible
joints (found on ph ysical examination; often with a complaint of pain) may present with
symptoms similar to those of deve lopmental coordination disorder.
Comorbidity
Disorders that commonly co-occur with deve lopmental coordination  disorder include
speech and language disorder; specific learning disorder (especially reading and writing);
problems of inattention, incl uding ADHD (the most frequent coexisting condition, with
about 50% co-occurrence); autism spectrum disord er; disruptive and emotional behavior
problems; and joint hypermobility syndrome. Different clusters of co-occurrence may be
present (e.g., a cluster with severe reading di sorders, fine motor problems, and handwriting


problems; another cluster with impaired movement control and motor planning). Presence
of other disorders does not exclude develo pmental coordination disorder but may make
testing more difficult and may independently interfere with th e execution of activities of
daily living, thus requiring examiner judgment in ascribing impairment to motor skills.
Stereotypic Movement Disorder
Diagnostic Criteria 307.3 (F98.4)
A. Repetitive, seemingly driven, and apparently purposeless motor behavior (e.g., hand
shaking or waving, body rocking, head banging, self-biting, hitting own body).
B. The repetitive motor behavior interferes wit h social, academic, or other activities and
may result in self-injury.
C. Onset is in the early developmental period.
D. The repetitive motor behavior is not attributable to the physiological effects of a sub-
stance or neurological condition and is no t better explained by another neurodevel-
opmental or mental disorder (e.g., trichotillomania [hair-pulling disorder], obsessive-
compulsive disorder).
Specify if:
With self-injurious behavior (or behavior that would result in an injury if preventive
measures were not used)
Without self-injurious behavior
Specify if:
Associated with a known medical or genetic condition, neurodevelopmental dis-
order, or environmental factor  (e.g., Lesch-Nyhan syndrome, intellectual disability
[intellectual developmental disorder], intrauterine alcohol exposure)


78 Neurodevelopmental Disorders
Coding note:  Use additional code to identify the associated medical or genetic
condition, or neurodevelopmental disorder.
Specify current severity:
Mild:  Symptoms are easily suppressed by sensory stimulus or distraction.
Moderate: Symptoms require explicit protective measures and behavioral modification.
Severe:  Continuous monitoring and protective m easures are required to prevent seri-
ous injury.
Recording Procedures
For stereotypic movement diso rder that is associated with a known medical or genetic
condition, neurodevelopmental disorder, or  environmental factor, record stereotypic
movement disorder associated with (name of condition, disorder, or factor) (e.g., stereo-
typic movement disorder associat ed with Lesch-Nyhan syndrome).
Specifiers
The severity of non-self-injurious stereotypi c movements ranges from  mild presentations
that are easily suppressed by a sensory stimul us or distraction to continuous movements
that markedly interfere with all activities of da ily living. Self-injurious  behaviors range in se-
verity along various dimensions, including the frequency, impact on adaptive functioning,
and severity of bodily injury (from mild bruising or erythema from hitting hand against
body, to lacerations or amputa tion of digits, to retinal detachment from head banging).
Diagnostic Features
The essential feature of stereotypic movement disorder is repetitive, seemingly driven,
and apparently purposeless motor behavior (Criterion A). These behaviors are often
rhythmical movements of the head, hands, or body without obvious adaptive function.
The movements may or may not respond to efforts to stop them. Among typically devel-
oping children, the repetitive movements may be stopped when attention is directed to
them or when the child is distracted from performing them. Among children with neuro-
developmental disorders, the behaviors are typically less responsive to such efforts. In


developmental disorders, the behaviors are typically less responsive to such efforts. In
other cases, the individual demonstrates self-restraining beha viors (e.g., sitting on hands,
wrapping arms in clothing, finding a protective device).
The repertoire of behaviors is variable; each individual presents with his or her own in-
dividually patterned, “signat ure” behavior. Examples of no n-self-injurious stereotypic
movements include, but are not limited to, bo dy rocking, bilateral flapping or rotating
hand movements, flicking or fl uttering fingers in front of the face, arm waving or flapping,
and head nodding. Stereotyped self-injurious behaviors include,  but are not limited to, re-
petitive head banging, face slapping, eye poki ng, and biting of hands, lips, or other body
parts. Eye poking is particularly concerning; it occurs more freq uently among children
with visual impairment. Multiple movements may be combined (e.g., cocking the head,
rocking the torso, waving a small string  repetitively in front of the face).
Stereotypic movements may oc cur many times during a da y, lasting a few seconds to
several minutes or longer. Frequency can vary  from many occurrences in a single day to
several weeks elapsing between episodes. The behaviors vary in context, occurring when
the individual is engrossed in other activities , when excited, stressed, fatigued, or bored.
Criterion A requires that the movements be  “apparently” purposeless. However, some
functions may be served by the movements. For example, stereotypic movements might
reduce anxiety in response to external stressors.
Criterion B states that the stereotypic mo vements interfere with social, academic, or


Criterion B states that the stereotypic mo vements interfere with social, academic, or
other activities and, in some children, may resu lt in self-injury (or would if protective mea-
sures were not used). If self-injury is present,  it should be coded using the specifier. Onset


Stereotypic Movement Disorder 79
of stereotypic movements is in the early deve lopmental period (Criterion C). Criterion D
states that the repetitive, stereotyped behavior  in stereotypic movement disorder is not at-
tributable to the physiological effects of a su bstance or neurological  condition and is not
better explained by another ne urodevelopmental or mental disorder. The presence of
stereotypic movements may indicate an unde tected neurodevelopmental problem, espe-
cially in children ages 1–3 years.
Prevalence
Simple stereotypic movements (e.g., rocking) ar e common in young typically developing chil-
dren. Complex stereoty pic movements are much less common (occurring in approximately
3%–4%). Between 4% and 16% of individuals with intellectual disability (intellectual develop-
mental disorder) engage in stereotypy and self-injury. The risk is greater in individuals with
severe intellectual disability. Among individual s with intellectual disability living in res-
idential facilities, 10%–15% may have stereo typic movement disord er with self-injury.
Development and Course
Stereotypic movements typically begin within the first 3 years of life. Simple stereotypic move-
ments are common in infancy and may be involve d in acquisition of motor mastery. In chil-
dren who develop complex motor stereotypies, approximately 80% exhibit symptoms before
24 months of age, 12% between 24  and 35 months, and 8% at 36 months or older. In most typ-
ically developing children, these movements resolve over time or can be suppressed. Onset of
complex motor stereotypies may be in infancy or later in the develo pmental period. Among


individuals with intellectual disability, the ster eotyped, self-injurious behaviors may persist
for years, even though the typography or pattern of self-injury may change.
Risk and Prognostic Factors
Environmental. Social isolation is a risk factor for self-stimulation that may progress to
stereotypic movements with repetitive self-inj ury. Environmental stress may also trigger
stereotypic behavior. Fear may alter physiological state, resulting in increased frequency
of stereotypic behaviors.
Genetic and physiological. Lower cognitive functioning is link ed to greater risk for stereo-
typic behaviors and poorer response to interv entions. Stereotypic movements are more fre-
quent among individuals with moderate-to-se vere/profound intellectual disability, who by
virtue of a particular syndrome (e.g., Rett syndrome) or environmental factor (e.g., an environ-
ment with relatively insufficient stimulation) se em to be at higher risk for stereotypies. Repet-
itive self-injurious behavior ma y be a behavioral phenotype in  neurogenetic syndromes. For
example, in Lesch-Nyhan syndrome, there are bo th stereotypic dystonic  movements and self-
mutilation of fingers, lip biti ng, and other forms of self-injury unless the individual is re-
strained, and in Rett syndrome and Cornelia de  Lange syndrome, self-i njury may result from
the hand-to-mouth st ereotypies. Stereotypic behaviors may result from a painful medical con-
dition (e.g., middle ear infection, de ntal problems, gastro esophageal reflux).
Culture-Related Diagnostic Issues
Stereotypic movement disorder, wi th or without self-injury, occurs in all races and cultures.
Cultural attitudes toward unusual behaviors may result in delayed diagnosis. Overall cultural


Cultural attitudes toward unusual behaviors may result in delayed diagnosis. Overall cultural
tolerance and attitudes toward stereotypic movement vary and mu st be considered.
Differential Diagnosis
Normal development. Simple stereotypic movements ar e common in infancy and early
childhood. Rocking may occur in the transition from sleep to awake, a behavior that usu-


80 Neurodevelopmental Disorders
ally resolves with age. Complex stereotypi es are less common in typically developing
children and can usually be suppressed by dist raction or sensory stimulation. The indi-
vidual’s daily routine is rarely affected, and the movements generally do not cause the
child distress. The diagno sis would not be appropriat e in these circumstances.
Autism spectrum disorder. Stereotypic movements may be a presenting symptom of
autism spectrum disorder and should be con sidered when repetitive movements and be-
haviors are being evaluated. Deficits of soci al communication and re ciprocity manifesting
in autism spectrum disorder are generally ab sent in stereotypic mo vement disorder, and
thus social interaction, social communication , and rigid repetitive behaviors and interests
are distinguishing features. Wh en autism spectrum disorder is present, stereotypic move-
ment disorder is diagnosed only when there is self-injury or when the stereotypic behav-
iors are sufficiently severe to  become a focus of treatment.
Tic disorders. Typically, stereotypies have an earlier age at onset (before 3 years) than
do tics, which have a mean age at onset of 5–7 years. They are consistent and fixed in their
pattern or topography compared with tics, which are variable in their presentation. Ste-
reotypies may involve arms, hands, or the entire body, while tics commonly involve eyes,
face, head, and shoulders. Stereotypies are more fixed, rhythmic, and prolonged in dura-
tion than tics, which, generally, are brief, ra pid, random, and fluctuating. Tics and stereo-
typic movements are both reduced by distraction.
Obsessive-compulsive and related disorders. Stereotypic movement disorder is dis-


Obsessive-compulsive and related disorders. Stereotypic movement disorder is dis-
tinguished from obsessive-co mpulsive disorder (OCD) by the absence of obsessions, as
well as by the nature of the repetitive behaviors. In OCD the individual feels driven to per-
form repetitive behaviors in response to an ob session or according to rules that must be ap-
plied rigidly, whereas in stereotypic movement disorder the behaviors are seemingly
driven but apparently purposeless. Trichot illomania (hair-pulling disorder) and excoria-
tion (skin-picking) disorder are characterize d by body-focused repetitive behaviors (i.e.,
hair pulling and skin picking) that may be seemingly driven but th at are not apparently
purposeless, and that may not be patterned or rhythmical. Furthermore, onset in tricho-
tillomania and excoriation disord er is not typically in the early developmental period, but
rather around puberty or later.
Other neurological and medical conditions. The diagnosis of stereotypic movements
requires the exclusion of habits, mannerisms, pa roxysmal dyskinesias, and benign he-
reditary chorea. A neurological history and examination are required to assess features
suggestive of other disorders, such as myoclo nus, dystonia, tics, and chorea. Involuntary
movements associated with a neurological co ndition may be distinguished by their signs
and symptoms. For example, repetitive, stereotypic movements in tardive dyskinesia can
be distinguished by a history of chronic neuroleptic use and characteristic oral or facial
dyskinesia or irregular trunk or limb movements. These type s of movements do not result
in self-injury. A diagnosis of stereotypic mo vement disorder is not appropriate for repet-


itive skin picking or scratching associated with amphetamine intoxi cation or abuse (e.g.,
patients are diagnosed with substance/medication-induced obsessi ve-compulsive and re-
lated disorder) and repetitive choreoathetoid  movements associated with other neurolog-
ical disorders.
Comorbidity
Stereotypic movement d isorder may occur as a primary diagnosis or secondary to another
disorder. For example, stereotypies are a common manifestation of a variety of neuro-
genetic disorders, such as Lesch-Nyhan syndrome, Rett syndrome, fragile X syndrome,
Cornelia de Lange syndrome, and Smith-Magenis syndrome. When stereotypic move-


genetic disorders, such as Lesch-Nyhan syndrome, Rett syndrome, fragile X syndrome,
Cornelia de Lange syndrome, and Smith-Magenis syndrome. When stereotypic move-
ment disorder co-occurs with another me dical condition, both should be coded.


Tic Disorders 81
Tic Disorders
Diagnostic Criteria
Note:  A tic is a sudden, rapid, recurrent, nonrhythmic motor movement or vocalization.
Tourette’s Disorder 307.23 (F95.2)
A. Both multiple motor and one or more vocal tics have been present at some time during
the illness, although not necessarily concurrently.
B. The tics may wax and wane in frequency but have persisted for more than 1 year since
first tic onset.
C. Onset is before age 18 years.
D. The disturbance is not attributable to the physiological effects of a substance (e.g., co-
caine) or another medical condition (e.g., Huntington’s disease, postviral encephalitis).
Persistent (Chronic) Motor or Vocal Tic Disorder 307.22 (F95.1)
A. Single or multiple motor or vocal tics have been present during the illness, but not both
motor and vocal.
B. The tics may wax and wane in frequency but have persisted for more than 1 year since
first tic onset.
C. Onset is before age 18 years.
D. The disturbance is not attributable to the physiological effects of a substance (e.g., co-
caine) or another medical condition (e.g., Huntington’s disease, postviral encephalitis).
E. Criteria have never been met for Tourette’s disorder.
Specify if:
With motor tics only
With vocal tics only
Provisional Tic Disorder 307.21 (F95.0)
A. Single or multiple motor and/or vocal tics.
B. The tics have been present for less than 1 year since first tic onset.
C. Onset is before age 18 years.


C. Onset is before age 18 years.
D. The disturbance is not attributable to the physiological effects of a substance (e.g., co-
caine) or another medical condition (e.g., Huntington’s disease, postviral encephalitis).
E. Criteria have never been met for Tourette’s disorder or persistent (chronic) motor or
vocal tic disorder.
Specifiers
The “motor tics only” or “vocal tics only” spec ifier is only required for persistent (chronic)
motor or vocal tic disorder.
Diagnostic Features
Tic disorders comprise four diagnostic categori es: Tourette’s disorder, persistent (chronic)
motor or vocal tic disorder, pr ovisional tic disorder, and the other specified and unspecified
tic disorders. Diagnosis for any tic disorder is  based on the presence of motor and/or vocal
tics (Criterion A), dura tion of tic symptoms (C riterion B), age at onse t (Criterion C), and ab-
sence of any known cause such as another medical condition or substance use (Criterion D).
The tic disorders are hierarchical in order (i .e., Tourette’s disorder, followed by persistent
[chronic] motor or vocal tic disorder, followed by provisional tic disorder, followed by the


82 Neurodevelopmental Disorders
other specified and unspecified tic disorders), such that once a tic disorder at one level of the
hierarchy is diagnosed, a lower hierarchy diagnosis cannot be made (Criterion E).
Tics are sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations. An
individual may have various tic symptoms over  time, but at any point in time, the tic rep-
ertoire recurs in a characteristic fashion. Although tics can include almost any muscle group
or vocalization, certain tic symptoms, such as  eye blinking or throat clearing, are common
across patient populations. Tics are generall y experienced as involun tary but can be vol-
untarily suppressed for varying lengths of time.
Tics can be either simple or complex. Simple motor tics  are of short duration (i.e., milli-
seconds) and can include eye blinking, should er shrugging, and extension of the extrem-
ities. Simple vocal tics include throat clea ring, sniffing, and grunting often caused by
contraction of the diaphragm or  muscles of the oropharynx. Complex motor tics  are of lon-
ger duration (i.e., seconds) and often include a combination of simple tics such as simul-
taneous head turning and shoulder shrugging . Complex tics can appear purposeful, such
as a tic-like sexual or obscene gesture ( copropraxia ) or a tic-like imitation of someone else’s
movements ( echopraxia). Similarly, complex vocal tics include repeating one’s own sounds
or words ( palilalia ), repeating the last-heard word or phrase ( echolalia ), or uttering socially
unacceptable words, including obscenities,  or ethnic, racial, or religious slurs ( coprolalia ).


Importantly, coprolalia is an abrupt, sharp ba rk or grunt utterance and lacks the prosody
of similar inappropriate speech observed in human interactions.
The presence of motor and/or vocal tics varies across the four tic disorders (Criterion
A). For Tourette’s disorder, both motor and vo cal tics must be present, whereas for per-
sistent (chronic) motor or vocal tic disorder, on ly motor or only vocal tics are present. For
provisional tic disorder, motor and/or vocal tics may be presen t. For other specified or un-
specified tic disorders, the movement disorder symptoms are best characterized as tics but
are atypical in presentation or age at onset, or have a known etiology.
The 1-year minimum duration criterion (Cri terion B) assures that individuals diag-
nosed with either Tourette’s disorder or pe rsistent (chronic) moto r or vocal tic disorder
have had persistent symptoms. Tics wax and wa ne in severity, and some individuals may
have tic-free periods of weeks to months; ho wever, an individual who has had tic symp-
toms of greater than 1 year’s duration since fi rst tic onset would be considered to have per-
sistent symptoms regardless of duration of ti c-free periods. For an individual with motor
and/or vocal tics of less than 1 year since firs t tic onset, a provisional tic disorder diagnosis
can be considered. There is no duration specif ication for other specif ied and unspecified tic
disorders. The onset of tics mu st occur prior to age 18 year s (Criterion C). Tic disorders
typically begin in the prepubertal period, with  an average age at onset between 4 and 6
years, and with the incidence of new-onset tic disorders decreasing in the teen years. New


years, and with the incidence of new-onset tic disorders decreasing in the teen years. New
onset of tic symptoms in adulthood is exceedin gly rare and is often associated with expo-
sures to drugs (e.g., excessive cocaine use) or is a result of a central nervous system insult
(e.g., postviral encephalitis). Although tic onse t is uncommon in teenagers and adults, it is
not uncommon for adolescents an d adults to present for an initial diagnostic assessment
and, when carefully evaluated, provide a histor y of milder symptoms dating back to child-
hood. New-onset abnormal move ments suggestive of tics out side of the us ual age range
should result in evaluation for other move ment disorders or for specific etiologies.


hood. New-onset abnormal move ments suggestive of tics out side of the us ual age range
should result in evaluation for other move ment disorders or for specific etiologies.
Tic symptoms cannot be  attributable to the physiologica l effects of a substance or an-
other medical condition (Criterion D). When there is strong eviden ce from the history,
physical examination, and/or laboratory resu lts to suggest a plausible, proximal, and
probable cause for a tic disorder, a diagnosis of other specified tic disorder should be used.
Having previously met diagnostic criteria fo r Tourette’s disorder negates a possible di-
agnosis of persistent (chronic) motor or vocal ti c disorder (Criterion E). Similarly, a previ-
ous diagnosis of persistent (chronic) motor or vocal tic disorder negates a diagnosis of
provisional tic disorder or ot her specified or unspecified tic disorder (Criterion E).


Tic Disorders 83
Prevalence
Tics are common in childhood but transient in most cases. The estimated prevalence of
Tourette’s disorder ranges from 3 to 8 per 1,000 in school-age children. Males are more
commonly affected than females, with the rati o varying from 2:1 to 4:1. A national survey
in the United States estimated 3 per 1,000 for the prevalence of clinically identified cases.
The frequency of identified cases was lower among African Americans and Hispanic
Americans, which may be related to differences in access to care.
Development and Course
Onset of tics is typically between ages 4 and 6 years. Peak severity occurs between ages 10
and 12 years, with a decline in severity during  adolescence. Many adults with tic disorders
experience diminished sympto ms. A small percentage of in dividuals will have persis-
tently severe or worsening symptoms in adulthood.
Tic symptoms manifest similarly in all age groups and across the lifespan. Tics wax and
wane in severity and change in affected muscle groups an d vocalizations over time. As
children get older, they begin to report th eir tics being associated with a premonitory
urge—a somatic sensation that precedes the tic—and a feeling of tension reduction follow-
ing the expression of the tic. Tics associated with a premonitory urge may be experienced
as not completely “involuntary” in that the ur ge and the tic can be resisted. An individual
may also feel the need to perform a tic in a specific way or repeat it until he or she achieves
the feeling that the tic has been done “just right.”
The vulnerability toward developing co-occurring conditions changes as individuals
pass through the age of risk for various co-o ccurring conditions. For example, prepubertal


children with tic disorders are more likely to experience attention-deficit/hyperactivity
disorder (ADHD), obsessive-co mpulsive disorder (OCD), and separation anxiety disorder
than are teenagers and adults, who are more li kely to experience the new onset of major
depressive disorder, substance use disorder, or bipolar disorder.
Risk and Prognostic Factors
Temperamental. Tics are worsened by anxiety, excitement, and exhaustion and are better
during calm, focused activities. Individuals ma y have fewer tics when engaged in schoolwork
or tasks at work than when relaxing at home after school or in the evening. Stressful/exciting
events (e.g., taking a test, participating in exciting activities) often make tics worse.
Environmental. Observing a gesture or sound in another person may result in an indi-
vidual with a tic disorder making a simila r gesture or sound, which may be incorrectly
perceived by others as purposeful. This can be a particular problem when the individual is
interacting with authority figures (e .g., teachers, supe rvisors, police).
Genetic and physiological. Genetic and environmental factors influence tic symptom
expression and severity. Important risk allele s for Tourette’s disorder and rare genetic
variants in families with tic disorders have  been identified. Obstetrical complications,
older paternal age, lower birth weight, and maternal smoking during pregnancy are as-
sociated with worse tic severity.
Culture-Related Diagnostic Issues
Tic disorders do not appear to vary in clinical  characteristics, course , or etiology by race,
ethnicity, and culture. However, race, ethnici ty, and culture may impa ct how tic disorders
are perceived and managed in the family an d community, as well as influencing patterns
of help seeking, and choices of treatment.


84 Neurodevelopmental Disorders
Gender-Related Diagnostic Issues
Males are more commonly affected than females,  but there are no gender differences in the
kinds of tics, age at onset, or course. Wome n with persistent tic disorders may be more
likely to experience anxiety and depression.
Functional Consequenc es of Tic Disorders
Many individuals with mild to moderate tic se verity experience no distress or impairment
in functioning and may even be unaware of their tics. Individuals with more severe symp-
toms generally have more impairment in daily living, but ev en individuals with moderate
or even severe tic disorders may function we ll. The presence of a co-occurring condition,
such as ADHD or OCD, can have greater impa ct on functioning. Less commonly, tics dis-
rupt functioning in daily activities and result in social isolation, interpersonal conflict,
peer victimization, inab ility to work or to go to school, and lower quality of life. The indi-
vidual also may experience substantial psycho logical distress. Rare complications of Tou-
rette’s disorder include physical injury, such as  eye injury (from hitting oneself in the face),
and orthopedic and neurological injury (e.g., disc disease related to forceful head and neck
movements).
Differential Diagnosis
Abnormal movements that may accompany other medical conditions and stereotypic
movement disorder. Motor stereotypies  are defined as involuntary rhythmic, repetitive,
predictable movements that appe ar purposeful but serve no obvious adaptive function or
purpose and stop with distraction. Examples  include repetitive hand waving/rotating,
arm flapping, and finger wiggling. Motor stereo typies can be differentiated from tics based
on the former’s earlier age at onset (younger than 3 years), prolonged duration (seconds to


minutes), constant repetitive fixed form and location, exacer bation when engrossed in ac-
tivities, lack of a premonitory urge, and ce ssation with distraction (e.g., name called or
touched). Chorea  represents rapid, random, continua l, abrupt, irregular, unpredictable,
nonstereotyped actions that are usually bilatera l and affect all parts of the body (i.e., face,
trunk, and limbs). The timing, direction, and dist ribution of movements vary from mo-
ment to moment, and movements usually worsen during attempted voluntary action. Dys-
tonia  is the simultaneous sustained contracture of both agonist and antagonist muscles,
resulting in a distorted posture or movement of parts of the bo dy. Dystonic postures are of-
ten triggered by attempts at voluntary movements and are not seen during sleep.
Substance-induced and paroxysmal dyskinesias. Paroxysmal dyskinesias usually oc-
cur as dystonic or choreoathetoid movement s that are precipitated by voluntary move-
ment or exertion and less commonly arise from normal background activity.
Myoclonus. Myoclonus is characterized by a sudden unidirectional movement that is
often nonrhythmic. It may be worsened by movement and occur du ring sleep. Myoclonus
is differentiated from tics by its rapidity, la ck of suppressibility, and absence of a premon-
itory urge.
Obsessive-compulsive and related disorders. Differentiating obsessive-compulsive
behaviors from tics may be difficult. Clues fa voring an obsessive-compulsive behavior in-
clude a cognitive-based drive (e.g., fear of co ntamination) and the n eed to perform the ac-


tion in a particular fashion a certain number of  times, equally on both sides of the body, or
until a “just right” feeling is achieved. Impulse-control proble ms and other repetitive be-
haviors, including persistent hair pulling, skin  picking, and nail biting, appear more goal
directed and complex than tics.


Other Specified Tic Disorder 85
Comorbidity
Many medical and psychiatric conditions have been described as co-occurring with tic disor-
ders, with ADHD and obsessive-compulsive and related disorders be ing particularly com-
mon. The obsessive-compulsive symptoms observed  in tic disorder tend to be characterized
by more aggressive symmetry and order symptoms and poorer response to pharmacotherapy
with selective serotonin reuptake inhibitors. Children with ADHD ma y demonstrate disrup-
tive behavior, social immaturi ty, and learning difficulties th at may interfere with academic
progress and interpersonal relationships and lead to greater impairment than that caused by a
tic disorder. Individuals with tic disorders can also have other movement disorders and other
mental disorders, such as depressive,  bipolar, or substance use disorders.
Other Specified Tic Disorder
307.20 (F95.8)
This category applies to presentations in which symptoms characteristic of a tic disorder
that cause clinically significant distress or impairment in social, occupational, or other im-
portant areas of functioning predominate but do not meet the full criteria for a tic disorder
or any of the disorders in the neurodevelopmental disorders diagnostic class. The other
specified tic disorder category is used in situations in which the clinician chooses to com-
municate the specific reason that the presentation does not meet the criteria for a tic disor-
der or any specific neurodevelopmental disorder. This is done by recording “other specified
tic disorder” followed by the specific reason (e.g., “with onset after age 18 years”).
Unspecified Tic Disorder
307.20 (F95.9)
This category applies to presentations in whic h symptoms characteristic of a tic disorder
that cause clinically significant distress or impairment in social, occupational, or other im-
portant areas of functioning predominate but do not  meet the full criteria for a tic disorder


or for any of the disorders in the neurodevelopmental disorders diagnostic class. The un-
specified tic disorder category is used in situations in which the clinician chooses not to
specify the reason that the criteria are not met for a tic disorder or for a specific neurode-
velopmental disorder, and includes presentations in which there is insufficient information
to make a more specific diagnosis.


86 Neurodevelopmental Disorders
Other Neurodevelopmental Disorders
Other Specified Neurodevelopmental Disorder
315.8 (F88)
This category applies to presentations in which symptoms characteristic of a neurodevel-
opmental disorder that cause impairment in social, occupational, or other important areas
of functioning predominate but do not meet the full criteria for any of the disorders in the
neurodevelopmental disorders diagnostic clas s. The other specified neurodevelopmental
disorder category is used in situations in which the clinician chooses to communicate the
specific reason that the presentation does not meet the criteria for any specific neurode-
velopmental disorder. This is done by recording “other specified neurodevelopmental dis-
order” followed by the specific reason (e.g., “neurodevelopmental disorder associated with
prenatal alcohol exposure”).
An example of a presentation that can be specified using the “other specified” desig-
nation is the following:
Neurodevelopmental disord er associated with pren atal alcohol exposure:  Neu-
rodevelopmental disorder associated with prenatal alcohol exposure is characterized
by a range of developmental disabilities following exposure to alcohol in utero.
Unspecified Neurodevelopmental Disorder
315.9 (F89)
This category applies to presentations in which symptoms characteristic of a neurodevel-
opmental disorder that cause impairment in social, occupational, or other important areas
of functioning predominate but do not meet the full criteria for any of the disorders in the
neurodevelopmental disorders diagnostic class. The unspecified neurodevelopmental dis-
order category is used in situations in which the clinician chooses not  to specify the reason
that the criteria are not met for a specific neurodevelopmental disorder, and includes pre-
sentations in which there is insufficient information to make a more specific diagnosis
(e.g., in emergency room settings).


87Schizophrenia Spectrum and
Other Psychotic Disorders
Schizophrenia spectrum  and other psychotic disorders include schizophrenia,
other psychotic disorders, and schizotypal (per sonality) disorder. They are defined by ab-
normalities in one or more of the following fi ve domains: delusions, hallucinations, disor-
ganized thinking (speech), grossly disorganiz ed or abnormal moto r behavior (including
catatonia), and negative symptoms.
Key Features That Define the Psychotic Disorders
Delusions
Delusions  are fixed beliefs that are not amenable to  change in light of conflicting evidence.
Their content may include a variety of themes (e.g., persecutory, referential, somatic, reli-
gious, grandiose). Persecutory delusions  (i.e., belief that one is going to be harmed, harassed,
and so forth by an individual, organizat ion, or other group) are most common. Referential
delusions  (i.e., belief that certain gestures, comm ents, environmental cues, and so forth are
directed at oneself) are also common. Grandiose delusions  (i.e., when an individual believes
that he or she has exceptional abilities, wealth, or fame) and erotomanic delusions  (i.e., when
an individual believes falsely that another person  is in love with him or her) are also seen.
Nihilistic delusions  involve the conviction that a ma jor catastrophe will occur, and somatic
delusions  focus on preoccupations regarding health and organ function.
Delusions are deemed bizarre  if they are clearly implausible and not understandable to
same-culture peers and do not derive from or dinary life experiences.  An example of a bi-
zarre delusion is the belief that an outside forc e has removed his or her internal organs and


replaced them with someone else’s organs wi thout leaving any wounds or scars. An ex-
ample of a nonbizarre delusion is the belief that  one is under surveilla nce by the police, de-
spite a lack of convincing evidence. Delusion s that express a loss of control over mind or
body are generally considered to be bizarre; these include th e belief that one’s thoughts
have been “removed” by some outside force (thought withdrawal ), that alien thoughts have
been put into one’s mind ( thought insertion ), or that one’s body or actions are being acted on
or manipulated by so me outside force ( delusions of control ). The distinction between a de-
lusion and a strongly held idea is sometimes di fficult to make and depends in part on the
degree of conviction with which the belief is held despite clear or reasonable contradictory
evidence regarding its veracity.
Hallucinations
Hallucinations  are perception-like experiences that occur without an external stimulus.
They are vivid and clear, with the full force and impact of normal perceptions, and not
under voluntary control. They may occur in any sensory modality, but auditory halluci-
nations are the most common in schizophrenia  and related disorders. Auditory hallucina-
tions are usually experienced as voices, whethe r familiar or unfamiliar, that are perceived
as distinct from the individual’s own though ts. The hallucinations must occur in the con-
text of a clear sensorium; those that occur while falling asleep ( hypnagogic ) or waking up


88 Schizophrenia Spectrum and Other Psychotic Disorders
(hypnopompic ) are considered to be within the rang e of normal experience. Hallucinations
may be a normal part of religious expe rience in certain cultural contexts.
Disorganized Thinking (Speech)
Disorganized thinking  (formal thought disorder ) is typically inferred from the individual’s
speech. The individual may switch from one topic to another ( derailment or loose associa-
tions ). Answers to questions may be oblique ly related or completely unrelated ( tangential-
ity). Rarely, speech may be so severely disorgan ized that it is nearly incomprehensible and
resembles receptive aphasia in its linguistic disorganization ( incoherence  or “word salad”).
Because mildly disorganized speech is common and nonspecific, the symptom must be se-
vere enough to substantially impair effective communication. The severity of the impair-
ment may be difficult to evaluate if the person making the diagnosis comes from a
different linguistic background than that of the person being examin ed. Less severe dis-
organized thinking or speech may occur du ring the prodromal and residual periods of
schizophrenia.
Grossly Disorganized or Abnormal Motor Behavior
(Including Catatonia)
Grossly disorganized or abnormal motor behavior  may manifest itself in a variety of ways,
ranging from childlike “silliness” to unpred ictable agitation. Problems may be noted in
any form of goal-directed behavior, leading to difficulties in performing activities of daily
living.
Catatonic behavior  is a marked decrease in reactivity to the environment. This ranges
from resistance to  instructions ( negativism ); to maintaining a rigid, inappropriate or bi-
zarre posture; to a complete lack  of verbal and motor responses ( mutism  and stupor ). It can


also include purposeless and excessive motor activity without obvious cause ( catatonic
excitement ). Other features are repeated stereo typed movements, staring, grimacing,
mutism, and the echoing of speech. Although catatonia has historically been associated
with schizophrenia, catatonic symptoms are nonspecific and may occur in other mental
disorders (e.g., bipolar or depressive disorder s with catatonia) and in medical conditions
(catatonic disorder due to another medical condition).
Negative Symptoms
Negative symptoms  account for a substantial portion of the morbidity associated with
schizophrenia but are less prominent in other psychotic disorders. Two negative symp-
toms are particularly prominent in schizophrenia: diminished emotional expression and
avolition. Diminished emotional expression includes reductions in the expression of emo-
tions in the face, eye contact, intonation of speech (prosody), and movements of the hand,
head, and face that normally give an emotional emphasis to speech. Avolition  is a decrease
in motivated self-initiated purposeful activities. The individual may sit for long periods of
time and show little interest in  participating in work or so cial activities. Other negative
symptoms include alogia, anhedonia, and asociality. Alogia  is manifested by diminished
speech output. Anhedonia  is the decreased ability to ex perience pleasure from positive
stimuli or a degradation in the recollection of pleasure previously experienced. Asociality
refers to the apparent lack of interest in so cial interactions and may be associated with avo-
lition, but it can also be a ma nifestation of limited opportunities for social interactions.
Disorders in This Chapter
This chapter is organized along a gradient of psychopathology. Clinicians should first con-
sider conditions that do not re ach full criteria for a psychotic disorder or are limited to one


Schizophrenia Spectrum and Other Psychotic Disorders 89
domain of psychopathology. Then they should  consider time-limited  conditions. Finally,
the diagnosis of a schizophrenia spectrum diso rder requires the exclusion of another con-
dition that may give rise to psychosis.
Schizotypal personality disorder  is noted within this chapter as it is considered within
the schizophrenia spectrum, although its full description is found in the chapter “Person-
ality Disorders.” The diagnosis schizotypal pers onality disorder captures a pervasive pat-
tern of social and interpersonal deficits, including reduced capacity for close relationships;
cognitive or perceptual distor tions; and eccentricities of behavior, usually beginning by
early adulthood but in some cases first becoming apparent in childhood and adolescence.
Abnormalities of beliefs, thinki ng, and perception are below the threshold for the diagno-
sis of a psychotic disorder.
Two conditions are defined by abnormalities limited to one domain of psychosis: delu-
sions or catatonia. Delusional disorder is characterized by at least 1 month of delusions but
no other psychotic symptoms. Catatonia is desc ribed later in the chapter and further in this
discussion.
Brief psychotic disorder lasts more than 1 day and remits by 1 month. Schizophreni-
form disorder is characterized by a symptomatic presentation equivalent to that of schizo-
phrenia except for its duration (less than 6 months) and the absence of a requirement for a
decline in functioning.
Schizophrenia lasts for at least 6 months an d includes at least 1 month of active-phase
symptoms. In schizoaffective disorder, a mood episode and the active-phase symptoms of
schizophrenia occur together an d were preceded or are followe d by at least 2 weeks of de-


lusions or hallucinations with out prominent mood symptoms.
Psychotic disorders may be induced by anot her condition. In substance/medication-
induced psychotic disorder, the psychotic symp toms are judged to be a physiological con-
sequence of a drug of abuse, a medication, or  toxin exposure and cease after removal of the
agent. In psychotic disorder due to anothe r medical condition, the psychotic symptoms
are judged to be a direct physiological consequence of another medical condition.
Catatonia can occur in severa l disorders, including neurod evelopmental, psychotic, bi-
polar, depressive, and other mental disorders.  This chapter also includes the diagnoses
catatonia associated with anot her mental disorder (catatonia  specifier), catatonic disorder
due to another medical condition, and unspecifie d catatonia, and the diagnostic criteria for
all three conditions are described together.
Other specified and unspecified schizophrenia spectrum and other psychotic disor-
ders are included for classifyin g psychotic presentations that do not meet the criteria for
any of the specific psychotic disorders, or  psychotic symptomatology about which there is
inadequate or contra dictory information.
Clinician-Rated Assessment of Symptoms and
 Related Clinical Phenomena in Psychosis
Psychotic disorders are heterogeneous, and th e severity of symptoms can predict impor-
tant aspects of the illness, such as the degree of cognitive or neur obiological deficits. To
move the field forward, a detailed framework fo r the assessment of severity is included in
Section III “Assessment Measures,” which may help with treatment planning, prognostic
decision making, and research on patho physiological mechanisms. Section III “Assess-
ment Measures” also contains dimensional as sessments of the primary symptoms of psy-
chosis, including hallucinations, delusions, disorganized speech (except for substance/


chosis, including hallucinations, delusions, disorganized speech (except for substance/
medication-induced psychotic disorder and psychotic disorder due to another medical
condition), abnormal psychomotor behavior, and negative symptoms, as well as dimen-
sional assessments of depression and mania. Th e severity of mood symptoms in psychosis


condition), abnormal psychomotor behavior, and negative symptoms, as well as dimen-
sional assessments of depression and mania. Th e severity of mood symptoms in psychosis
has prognostic value  and guides treatment. There is growing evidence that schizoaffective


90 Schizophrenia Spectrum and Other Psychotic Disorders
disorder is not a distinct nosological catego ry. Thus, dimensional assessments of depres-
sion and mania for all psychotic disorders alert clinicians to mood pathology and the need
to treat where appropriate. The Section III sc ale also includes a dimensional assessment of
cognitive impairment. Many individuals with psychotic disorders have impairments in a
range of cognitive domains that predict functi onal status. Clinical neuropsychological as-
sessment can help guide diagnosis and treatm ent, but brief assessments without formal
neuropsychological assessment can provide us eful information that can be sufficient for
diagnostic purposes. Formal neuropsychological  testing, when conducted, should be ad-
ministered and scored by personnel trained in  the use of testing instruments. If a formal
neuropsychological assessment is not conducted, the clinician should use the best avail-
able information to make a judgment. Furthe r research on these assessments is necessary
in order to determine their c linical utility; thus, the assessments available in Section III
should serve as a prototype to  stimulate such research.
Schizotypal (Personality) Disorder
Criteria and text for schizotypal personality disorder can be found in the chapter “Person-
ality Disorders.” Because this disorder is cons idered part of the schizophrenia spectrum of
disorders, and is labeled in this section of ICD-9 and ICD-10 as schizotypal disorder, it is
listed in this chapter and disc ussed in detail in the DSM-5 chapter “Personality Disorders.”
Delusional Disorder
Diagnostic Criteria 297.1 (F22)
A. The presence of one (or more) delusions with a duration of 1 month or longer.
B. Criterion A for schizophrenia has never been met.


B. Criterion A for schizophrenia has never been met.
Note:  Hallucinations, if present, are not prominent and are related to the delusional
theme (e.g., the sensation of being infested with insects associated with delusions of
infestation).
C. Apart from the impact of the delusion(s) or  its ramifications, functioning is not markedly
impaired, and behavior is not obviously bizarre or odd.
D. If manic or major depressive episodes have occurred, these have been brief relative
to the duration of the delusional periods.
E. The disturbance is not attributable to the physiological effects of a substance or an-
other medical condition and is not better ex plained by another mental disorder, such
as body dysmorphic disorder or obsessive-compulsive disorder.
Specify whether:
Erotomanic type:  This subtype applies when the central theme of the delusion is that
another person is in love with the individual.
Grandiose type:  This subtype applies when the central theme of the delusion is the
conviction of having some great (but unrecognized) talent or insight or having made
some important discovery.
Jealous type:  This subtype applies when the central theme of the individual’s delusion
is that his or her spouse or lover is unfaithful.
Persecutory type: This subtype applies when the central theme of the delusion in-
volves the individual’s belief that he or she is being conspired against, cheated, spied
on, followed, poisoned or drugged, maliciously maligned, harassed, or obstructed in
the pursuit of long-term goals.
Somatic type:  This subtype applies when the central theme of the delusion involves
bodily functions or sensations.


Delusional Disorder 91
Mixed type: This subtype applies when no one delusional theme predominates.
Unspecified type: This subtype applies when the dominant delusional belief cannot
be clearly determined or is not described in the specific types (e.g., referential delu-
sions without a prominent persecutory or grandiose component).
Specify if:
With bizarre content:  Delusions are deemed bizarre if they are clearly implausible, not
understandable, and not derived from ordinary li fe experiences (e.g., an individual’s be-
lief that a stranger has removed his or her internal organs and replaced them with some-
one else’s organs without leaving any wounds or scars).
Specify if:
The following course specifiers are only to be used after a 1-year duration of the disorder:
First episode, currentl y in acute episode:  First manifestation of the disorder meet-
ing the defining diagnostic symptom and time criteria. An acute episode is a time pe-
riod in which the symptom criteria are fulfilled.
First episode, currently in partial remission:  Partial remission  is a time period dur-
ing which an improvement after a previous episode is maintained and in which the de-
fining criteria of the disorder are only partially fulfilled.
First episode, currently in full remission:  Full remission  is a period of time after a
previous episode during which no disorder-specific symptoms are present.
Multiple episodes, curr ently in acute episode
Multiple episodes, currently in partial remission
Multiple episodes, currently in full remission
Continuous:  Symptoms fulfilling the diagnostic symptom criteria of the disorder are
remaining for the majority of the illness course, with subthreshold symptom periods be-
ing very brief relative to the overall course.
Unspecified
Specify current severity:
Severity is rated by a quantitative assessment of the primary symptoms of psychosis,