Diagnosis and Evaluation of Pervasive Developmental Disorders.

Accurate diagnosis and appropriate treatment of pervasive developmental disorders (PDDs), includingautistic disorder, Asperger’s disorder, and pervasive developmental disorder not otherwisespecified, are necessary to ensure the best possible outcomes for children with these disorders. In thepast, it was not uncommon for children with PDDs to wait several years from the time of parentalrecognition of developmental delay to the determination of the correct diagnosis and initiation oftreatment. Increased awareness of PDDs and the availability of better assessment tools have improvedthe detection of these conditions in children. A wide variety of standardized diagnostic checklists, interviews,and observational measures are available to assist the clinician in making an accurate PDDdiagnosis. A comprehensive evaluation also establishes a baseline of adaptive functioning and problematicbehavior, which is essential for subsequent assessment of progress. This article discusses thedifferential diagnosis and evaluation of PDDs, focusing on the various assessment tools. The elementsof a contemporary diagnostic evaluation and behavioral assessment are presented. The application ofdiscretionary evaluations for special situations are also introduced.