Autism: A Medical Primer -- American Family Physician

www.aafp.org/afp AMERICAN FAMILY PHYSICIAN 1667 Definition Autistic disorder is a pervasive developmental disorder defined behaviorally as a syndrome consisting of abnormal development of social skills (withdrawal, lack of interest in peers), limitations in the use of interactive language (speech as well as nonverbal communication), and sensorimotor deficits (inconsistent responses to environmental stimuli). In this article, the more generic terms autism and autistic refer to the broad spectrum of pervasive developmental disorders that exhibit autistic features as their primary presenting behaviors. The term autistic disorder is used to describe the specific developmental disorder that occurs at the more severely affected end of this spectrum (Table 1). The development of impairments in autistic persons is varied (Table 2) and characteristically uneven, resulting in good skills in some areas and poor skills in others. Echolalia, the involuntary repetition of a word or a sentence just spoken by another person, is a common feature of language impairment that, when present, may cause language skills to appear better than they really are. There may also be deficiencies in symbolic thinking, stereotypic behaviors (e.g., repetitive nonproR ecognition of the disorder called autism may have its origin in Itard’s 1801 description of the “wild boy of Aveyron,” a violent child with no language skills who related to other people as if they were objects. It was not until 1943 that Kanner identified a complex set of characteristics (e.g., aberrations in social development, verbal and nonverbal communication, symbolic thinking) for a syndrome he labeled “autism.” Although Kanner theorized that a single, biologically based defect was responsible for the development of autistic disorders, treatment in the 1950s and 1960s was dominated by the psychodynamic theory of the etiology of autism that charged that pathologic parenting was responsible for the withdrawal of children from their environment. Following the 1970s discovery of neuroreceptors, endogenous neurohormones, and the stereospecific binding sites of neuropeptides to neurons, clinicians have discounted the psychodynamic theory of autism and repostulated Kanner’s original supposition that biologically based deficits are responsible for the etiology of autism. Autistic disorder, a pervasive developmental disorder resulting in social, language, or sensorimotor deficits, occurs in approximately seven of 10,000 persons. Early detection and intervention significantly improve outcome, with about one third of autistic persons achieving some degree of independent living. Indications for developmental evaluation include no babbling, pointing, or use of other gestures by 12 months of age, no single words by 16 months of age, no two-word spontaneous phrases by 24 months of age, and loss of previously learned language or social skills at any age. The differential diagnosis includes other psychiatric and pervasive developmental disorders, deafness, and profound hearing loss. Autism is frequently associated with fragile X syndrome and tuberous sclerosis, and may be caused by lead poisoning and metabolic disorders. Common comorbidities include mental retardation, seizure disorder, and psychiatric disorders such as depression and anxiety. Behavior modification programs are helpful and are usually administered by multidisciplinary teams; targeted medication is used to address behavior concerns. Many different treatment approaches can be used, some of which are unproven and have little scientific support. Parents may be encouraged to investigate national resources and local support networks. (Am Fam Physician 2002;66:1667-74,1680. Copyright© 2002 American Academy of Family Physicians.) Autism: A Medical Primer