Pervasive Developmental Disorders: Distinguishing Among Subtypes

Abstract

Abstmct: Pervasive developmental disorders (PDDs) are severe and pervasive conditions that begin in early life and influence multiple areas of development. In addition to the more commonly known autistic disorder, these conditions include Asperger’s disorder, Rett’s disorder, childhood disintegrative disorder, and pervasive developmental disorder “not otherwise specified.” Intensive behavioral intervention at an early age has been documented to improve the developmental trajectory of many of these children, and this treatment is therefore essential from the preschool years on. The school psychologist has a vital role to play in diagnosis, assessment, and classroom consultation for children with PDDs. The term peq-uasive developmental disorders in the fourth edition of the Diagnostic and Statistical Manual of Nlental Disorders (DSM-IV; American Psychiatric Association [APA], 1994) refers to a group of severe and pervasive conditions that begin in infancy or early childhood, and have an impact on several areas of development including socialization, language, and stereotyped or perseverative behaviors. A major change from the previous edition of the diagnostic manual, DSM-III-R (APA, 1987) to DSM-IV is the addition of more subtypes of pervasive developmental disorders (PDDs). DSM-III-R had two categories, autistic disorder and pervasive developmental disorder not otherwise specified (PDD-NOS). DSM-IV expands this list to include Asperger’s disorder, Rett’s disorder, and childhood disintegrative disorder. The revisions in diagnostic criteria have made DSM-IV a more precise system than DSM-III or DSM-III-R (Volkmar, Cicchetti, Bregman, & Cohen, 1992; Volkmar et al., 1994). This expansion may ultimately enhance the study of etiology and treatment. In this article we briefly review each of these diagnoses, and consider their value for the school psychologist.