Kaplan + Sadock's Synopsis of Psychiatry, 11e

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31.5 Autism Spectrum Disorder

Table 31.5-2 Autism Spectrum Disorder versus Childhood Onset Schizophrenia

Criteria

Autism Spectrum Disorder

Schizophrenia (with Onset before Puberty)

Age of onset

Early developmental period

Rarely under 5 years of age

< 1 in 10,000

Incidence

1 percent

Sex ratio (M:F)

4:1

1.67:1 (slight preponderance of males)

Family history of schizophrenia Not increased

Likely Increased Not increased

Prenatal and perinatal complications Behavioral characteristics

Increased

Poor social relatedness; may have aberrant language, speech or echolalia; stereotyped phrases; may have stereotypies, repetitive behaviors

Hallucinations and delusions; thought disorder

Adaptive functioning Level of intelligence

impaired

Deterioration in functioning

Wide range, may be intellectually disabled (30 percent) Typical higher performance than verbal

Usually within normal range, may be low average normal

Pattern of IQ

More even

Grand mal seizures

4 percent to 32 percent

low incidence

(Adapted from Magda Campbell, M.D., and Wayne Green, M.D.)

Intellectual disabilitywithBehavioral Symptoms Children with intellectual disability may exhibit behavioral symptoms that overlap with some autism spectrum disorder features. The main differentiating features between autism spectrum disorder and intellectual disability are that children with intellectual disability syndromes generally display global impairments in both verbal and nonverbal areas, whereas chil- dren with autism spectrum disorder are relatively weak in social interactions compared to other areas of performance. Children with intellectual disability generally relate verbally and socially to adults and peers in accordance with their mental age, and they exhibit a relatively even profile of limitations. Language Disorder Some children with language disorders also have autism spec- trum disorder features, which may present a diagnostic chal- lenge. Table 31.5-3 summarizes the major differences between autism spectrum disorder and language disorders.

responding to verbal and nonverbal cues of a listener. Other forms of language impairment may accompany social com- munication disorder such as delay in learning language or expressive and receptive difficulties. Social communication disorder is found with greater frequency in relatives of indi- viduals with autism spectrum disorder, which increases the difficulty in discriminating this disorder from autism spectrum disorder. Although relationships may be negatively affected by social communication disorder, this disorder does not include restricted or repetitive behaviors and interests, as autism spec- trum disorder does. Childhood Onset Schizophrenia Schizophrenia is rare in children younger than 12 years and almost nonexistent before the age of 5 years. Characterized by hallucinations or delusions, childhood onset schizophrenia has a lower incidence of seizures and intellectual disability and poor social skills. Table 31.5-2 compares autism spectrum disorder and schizophrenia with childhood onset.

Table 31.5-3 Autism Spectrum Disorder versus Language Disorder

Criteria

Autism Spectrum Disorder

Language Disorder

Incidence

1 percent

5 of 10,000

Sex ratio (M:F)

4:1

Equal or almost equal sex ratio

< 25 percent of cases

< 25 percent of cases

Family history of speech delay or language problems

Associated deafness

Very infrequent

Not infrequent Actively utilized

Nonverbal communication (e.g., gestures) Language abnormalities (e.g., echolalia, stereotyped phrases out of context)

Impaired

Present in a subset

Uncommon

Articulation problems

Infrequent

frequent

Intellectual level

Impaired in a subset (about 30 percent)

Uncommon, less frequently severe

Patterns of intelligence quotient (IQ) tests Typically lower on verbal scores than performance scores;

Often verbal scores lower than performance scores

Impaired social communication, restricted and repetitive behaviors,

Present

Absent or, if present, mild

Imaginative play

Often impaired

Usually in tact

(Adapted from Magda Campbell, M.D., and Wayne Green, M.D.)