Interest in autism and autism spectrum disorders (ASDs) has increased dramatically over the past decade.1 The convergence of approaches to diagnosis that are based on the DSM-IV and International Statistical Classification of Diseases, 10th Revision, fostered this effort, as did a major and sustained increase in federal funding鈥攕timulated in large part by increasing pressure from parents. This interest has extended to treatment programs as well. For example, the report 鈥淓ducating Young Children With Autism,鈥� from the National Research Council, summarized the importance of early and sustained intervention for improving long-term outcomes.2,3 A growing body of research has also demonstrated a high rate of comorbid conditions that lead to additional functional impairment.4,5