ABSTRACT
C H A P T E R 14 Pervasive Developmental Disorders
The term pervasive developmental disorders (PDD) refers to a continuum of disorders that are characterized by severe impairments in three areas of functioning: social behavior, verbal and nonverbal communication, and the presence of stereotyped, repetitive patterns of behavior, according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, revised text (American Psychiatric Association; DSM-IV-TR, 2000). The terms Autistic Spectrum Disorders and Pervasive Developmental Disorders are used interchangeably to describe this cluster of disorders that includes autistic disorder, Asperger’s disorder, pervasive developmental disorder — not otherwise specified (PPDNOS), Retts disorder, and childhood disintegrative disorder. PDD should be distinguished from the broader term of developmental disability that includes a range of disorders (e.g., cerebral palsy, epilepsy, and mental retardation) that have an impact on development of processes such as language, learning, mobility, and self-care (Olley & Guttentag, 1999). Although procedures outlined in this chapter apply to the full range of pervasive developmental disorders, there is currently very little literature addressing the differential diagnosis of Rett’s disorder and childhood disintegrative disorder based on psychological assessments. The current
chapter will focus primarily on the use of psychological assessments in autistic disorder, Asperger’s disorder, and PDD-NOS.
