Autism Spectrum Disorders

Autism

Autism is a disorder that is first diagnosed in childhood. Children with autism demonstrate qualitative deficits in their social interaction with others—in communication and play skills—and demonstrate restricted or stereotyped interests and behaviors. In 1943, Kanner was the first to describe the characteristics of children with autism, based on a sample of 11 children he saw in his office with a similar constellation of symptoms (Kanner, 1943). Although the defining characteristics of autism have been refined over the years, the essential cluster of social interaction, communication, and restrictive behaviors/interests have remained. Initially considered to be a relatively rare disorder, recent studies indicate that autism may be more prevalent than previously recognized. The DSM-IV indicates a prevalence rate of 2 to 5 cases per 10,000 individuals. More recent studies suggest that the prevalence rate may be as high as 1 case per 1,000 individuals (Gillberg & Coleman, 2000). Likewise, the incidence of autism appears to be increasing, although reasons for this remain unclear; it may be related to increased public and health provider awareness and more effective differential diagnostic assessment. There is approximately a boy-to-girl ratio of 4:1 with a diagnosis of autism. There are no differences in prevalence rate in terms of socioeconomic class, culture, race, or ethnicity.

The etiology of autism is unknown. There were early misconceptions that it was caused by poor or inadequate parenting (Table 1). This viewpoint has largely been discredited. More likely, autism is the result of a confluence of environmental and genetic variables. Scientific inquiry at this time is focused on identifying genetic variables and neurological variables common in children with autism. There are some medical conditions that have a higher rate of autism associated with them—such as tuberous sclerosis, fragile X syndrome, or maternal rubella—and the autism characteristics are likely related to the neurological deficits associated with the medical condition.

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