This summary provides an overview of the assessment and treatment recommendations contained in the Practice Parameters for the Assessment and Treatment of Children, Adolescents, and Adults With Autism and Other Pervasive Developmental Disorders. The parameters were written to aid clinicians in the assessment and treatment of children and adolescents with autism and other pervasive developmental disorders. Autism and the related pervasive developmental disorders are characterized by patterns of delay and deviance in the development of social, communicative, and cognitive skills, which arise in the first years of life. Although frequently associated with mental retardation, these conditions are distinctive in terms of their course and treatment. These conditions have a wide range of syndrome expression, and their management presents particular challenges for clinicians. Individuals with these conditions can present for clinical care at any point in development. The multiple developmental and behavioral problems associated with these conditions often require the care of multiple providers; coordination of services and advocacy for individuals and their families is important. Early, sustained intervention is indicated, as is the use of various treatment modalities (e.g., pharmacotherapy, special education, speech/communication therapy, and behavior modification. [ABSTRACT FROM AUTHOR]