Abstract
Autism is one of the most widely recognized and reliably diagnosed developmental disorders. There is general professional consensus that autism is biologically based, with a strong genetic component and likely involvement of various neural structures. Distinct deficits in social reciprocity and relatedness are often apparent early in development, typically by 12 to 15 months, with reliable and valid diagnosis usually possible by 24 months. Early and intensive behaviorally based treatment, in particular the use of applied behavior analysis, is effective in systematically teaching skills and reducing problematic behaviors. Despite evidence of efficacy, however, the limited availability of quality behavioral services for children with autism is a significant barrier to effective treatment.