Autism

Autism is a complex neurodevelopmental disorder that is behaviorally defined. The behavioral manifestations that define autism include qualitative deficits in social interaction and communication and restricted repetitive and stereotyped patterns of behavior, activities, and interests [1]. Autism defines children at a behavioral level and is associated with multiple etiologies. The phenotypic presentation of autism is influenced by factors that are not part of the defining features of this disorder. One aspect of autism that is not part of the diagnostic criteria but is an important prognostic indicator is cognitive ability. The wide range of social skills, communication abilities, and patterns of behavior that occur in autism are best captured by the term "autism spectrum disorders" (ASDs) [2,3]. Autism is a prototype disorder of sociocognitive development that provides an important opportunity to observe and delineate the regions of the brain that are responsible for behaviors that define social cognition and communication. Recent reports indicate that there is an explosion of children given the diagnosis of an ASD. Prevalence figures range from 4 to 10 per 10,000 up to 2 to 5 per 1000 [4]. Reports disagree, however, on whether or not prevalence truly has increased. One explanation for the increased diagnosis is that there is a greater awareness of the ASDs, especially in mildly affected children and in those with severe mental retardation [5]. The purpose of this article is to review the current clinical and neurobiologic understanding of autism.