Kaplan + Sadock's Synopsis of Psychiatry, 11e

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31.5 Autism Spectrum Disorder

Prenatal and Perinatal Factors A higher-than-expected incidence of prenatal and perinatal complications seems to occur in infants who are later diag- nosed with autism spectrum disorder. The most significant prenatal factors associated with autism spectrum disorder in the offspring are advanced maternal and paternal age at birth, maternal gestational bleeding, gestational diabetes, and first- born baby. Perinatal risk factors for autism spectrum disorder include umbilical cord complications, birth trauma, fetal dis- tress, small for gestational age, low birth weight, low 5-minute Apgar score, congenital malformation, ABO blood group sys- tem or Rh factor incompatibility and hyperbilirubinemia. Many of the obstetrical complications that are associated with risk for autism spectrum disorder are also risk factors for hypoxia, which may be an underlying risk factor itself. There is not suf- ficient evidence to implicate any one single perinatal or prena- tal factor in autism spectrum disorder etiology, and a genetic predisposition to autism spectrum disorder may be interacting with perinatal factors. Comorbid Neurological Disorders Electroencephalography (EEG) abnormalities and seizure dis- orders occur with greater than expected frequency in individu- als with autism spectrum disorder. Four percent to 32 percent of individuals with autism spectrum disorder have grand mal sei- zures at some time, and about 20 to 25 percent show ventricular enlargement on computed tomography (CT) scans. Various EEG abnormalities are found in 10 to 83 percent of children with the previously defined autistic disorder, and although no EEG finding is specific to autistic disorder, there is some indication of failed cerebral lateralization. The current consensus is that autism spec- trum disorder is a set of behavioral syndromes caused by a multi- tude of factors acting on the central nervous system. Psychosocial Theories Studies comparing parents of children with autism spectrum disorder with parents of normal children have shown no sig- nificant differences in child-rearing skills. Kanner’s early specu- lations that parental emotional factors might be implicated as contributing to the development of autism spectrum disorder have been clearly refuted. Diagnosis and Clinical Features The DSM-5 diagnostic criteria for autism spectrum disorder are shown in Table 31.5-1. Core Symptoms of Autism Spectrum Disorder Persistent Deficits In Social Communication and Interaction.  Children with autism spectrum disorder char- acteristically do not conform to the expected level of recipro- cal social skills and spontaneous nonverbal social interactions. Infants with autism spectrum disorder may not develop a social smile, and as older babies may lack the anticipatory posture for being picked up by a caretaker. Less frequent and poor eye contact is common during childhood and adolescence

compared to other children. The social development of chil- dren with autism spectrum disorder is characterized by atypi- cal, but not absent, attachment behavior. Children with autism spectrum disorder may not explicitly acknowledge or differen- tiate the most important persons in their lives—parents, sib- lings, and teachers—and on the other hand, may not react as strongly to being left with a stranger compared to others their age. Children with autism spectrum disorder often feel and dis- play extreme anxiety when their usual routine is disrupted. By the time children with autism spectrum disorder reach school age, their social skills may have increased, and social with- drawal may be less obvious, particularly in higher-functioning children. An observable deficit, however, often remains in spontaneous play with peers and in subtle social abilities that promote developing friendships. The social behavior of chil- dren with autism spectrum disorder is often awkward and may be inappropriate. In older school-aged children, social impair- ments may be manifested in a lack of conventional back and forth conversation, fewer shared interests, and fewer body and facial gestures during conversations. Cognitively, children with autism spectrum disorder are frequently more skilled in visual- spatial tasks than in tasks requiring skill in verbal reasoning. One observation of the cognitive style of children with autism spectrum disorder is an impaired ability to infer the feelings or emotional state of others around them. That is, individuals with autism spectrum disorder have difficulty with making attribu- tions about the motivation or intentions of others (also termed “theory of mind”) and thus have difficulty developing empathy. The lack of a “theory of mind” produces difficulties interpret- ing the social behavior of others and leads to a lack of social reciprocation. Individuals with autism spectrum disorder generally desire friendships, and higher functioning children may be aware that their lack of spontaneity and poor skills in responding to the emotions and feelings of their peers are major obstacles in developing friendships. Children with autism spectrum disorder are often avoided or shunned by peers who expect them to con- form to their mainstream activities, and experience their behav- ior as awkward and alienating. Adolescents and adults with autism spectrum disorder often desire romantic relationships, and for some, their increase in social competence and skills over time enables them to develop long-term relationships. Restricted, Repetitive Patterns of Behavior, Interests, and Activities.  From the first years of life, in a child with autism spectrum disorder, developmentally expected exploratory play is restricted and muted. Toys and objects may not be used typically, instead, are often manipulated in a ritualistic man- ner, with fewer symbolic features. Children with autism spec- trum disorder generally do not show the level of imitative play or abstract pantomime that other children of their age exhibit spontaneously. The activities and play of children with autism spectrum disorder may appear more rigid, repetitive, and monot- onous than their peers. Ritualistic and compulsive behaviors are common in early and middle childhood. Children with autism spectrum disorder often seem to enjoy spinning, banging, and watching water flowing. Frank compulsive behaviors are not uncommon among children with autism spectrum disorder, such as lining up objects, and not infrequently a child with autism spectrum disorder may exhibit a strong attachment to a particular