Autistic disorder

A severe neuropsychiatric disorder of early childhood onset, historically regarded as a psychosis of childhood but now classified as a pervasive developmental disorder. While autism has been the most intensively studied pervasive developmental disorder, other conditions are now included in this class of conditions: Asperger's syndrome (sometimes referred to as autistic psychopathy), Rett's syndrome, and childhood disintegrative disorder (Heller's syndrome).

Symptoms of autism generally are apparent within the first 2 years of life and may occasionally be noted from the time of birth. Characteristic disturbances include disruption of social, cognitive, linguistic, motor, and perceptual development. Affected individuals fail to develop appropriate interpersonal relationships. In about half of the cases, language fails to develop; when it does develop, it is characterized by pronoun confusion (for example, the use of “you” for “I”), abnormal speech tone or rhythm, and an impaired ability to use abstract terms or communicate symbolic information. Unusual responses to the environment are common and may include resistance to change, exaggerated reactions to sensory stimuli or changes in the environment, ritualistic behavior, and peculiar attachments to inanimate objects. Motor abnormalities include unusual posturing and stereotyped (purposeless and repetitive) movements; self-injurious behavior (for example, head banging) is also common. Although some islets of unusual ability (in memory, drawing, or calculation) may be present, about 80% of individuals score in the mentally retarded range on tests of intelligence. Autistic individuals do not experience delusions and hallucinations; however, the metaphorical and bizarre language of verbal individuals may mistakenly suggest the kind of thought disturbance that is found in schizophrenia. See Schizophrenia

In Rett's syndrome, a short period of normal development is followed by loss of developmental skills and marked psychomotor retardation. A brief autisticlike phase may be observed during the preschool period, but the subsequent course and clinical features are markedly different from those of autism. Rett's syndrome has been observed only in females. The validity of Asperger's syndrome apart from autism has been more controversial. Individuals with Asperger's syndrome appear to have relatively much more preserved verbal and cognitive skills. Unusual circumscribed interests are common (for example, in maps, the weather, or train or bus schedules). In childhood disintegrative disorder, development in the first several years of life is unequivocally normal and is followed by a marked developmental regression (a child who previously had been speaking in sentences becomes totally mute), and various autistic features develop.

Autism is chronic and incapacitating. Only one autistic individual in six is able to make a good adjustment in adulthood and engage in regular, gainful employment. Approximately two-thirds of children remain severely handicapped as adults and need constant supervision and support. Even for those autistic individuals who make the best adjustment as adults, residual deficits in social, affective, and cognitive development remain. Factors related to better prognosis include the development of communication skills by age 5 and intellectual achievement. In Asperger's syndrome, the prognosis is apparently better than in autism, probably reflecting, in some part, the preservation of cognitive abilities in this condition. In Rett's syndrome and childhood disintegrative disorder, the prognosis is worse than in autism.

The “purest” form of autism, where the child has higher IQ, some islets of normal or near-normal behavior, and profound social detachment, affects only 1 child in 2000; however, the broader spectrum of communication and developmental disorders associated with autism and requiring similar care may affect 1 in every 750 children. Although males outnumber females (by four or five times), females with autism tend to be more severely affected. Predisposing factors include congenital infections (for example, maternal rubella) and metabolic and genetic illnesses (for example, phenylketonuria). A history of prenatal or perinatal complication is not uncommon, but in many cases no specific predisposing factor or associated mental condition is found. See Rubella

For the majority of cases of autism, the cause remains unknown. Theoretical explanations have emphasized either a primary psychological or biological vulnerability in the child, the role of environmental factors, and an interaction between an inborn vulnerability and the child's environment. The high incidence of neurological signs, electroencephalographic abnormalities, and the fact that seizures develop in 25% of children during adolescence (especially in lower-IQ children) tend to support the role of a biological vulnerability. The final behavioral expression of the syndrome may be a function of multiple factors. Individuals with Rett's syndrome and childhood disintegrative disorder also are at increased risk for developing seizures, and exhibit other signs of central nervous system dysfunction. The history of a prolonged period of normal development in childhood disintegrative disorder often prompts extensive medical investigation, which usually does not reveal a specific medical condition that might account for the deterioration.

Treatment modalities that have been used in the management of individuals with autism and related conditions include psychotherapy, pharmacotherapy, behavior therapy, various somatic treatments, and educational interventions. Certain drugs may be effective in controlling certain maladaptive behavioral features, such as hyperactivity, aggression, and stereotyped behaviors. Behavior modification procedures may be quite useful. Educational interventions with highly structured, intensive remediation are of greatest overall benefit. However, even with the best of interventions there are no cures and most autistic individuals remain severely impaired. See Psychotherapy