One out of every ten children in the U.S. is affected by a pervasive developmental disorder (PPD). This comprehensive volume examines in depth the neuropsychological foundations of these disorders, providing up-to-date, detailed information on the full range of diagnostic, assessment, and treatment tools available to help children suffering from PDDs. With an eye to greater diagnostic clarity, leading researchers and practitioners of neuropsychology, neurology, psychiatry, and clinical psychology discuss the phenomena of the presentations of PDD as they correspond to their neuropsychological features. They address the neuropathological and pathophysiological bases of each presentation and how these factors correspond with functional outcomes in regard to neuropsychological, emotional, behavioural, and social outcomes. The manner by which these factors are assessed, and how that information is used to differentially diagnose, will be discussed at length, along with methods of intervention. The interdisciplinary nature of this volume will make it of interest to practitioners and researchers in the field of neurology, psychiatry, paediatrics, school psychology, and clinical psychology. Key Features: Covers the full range of identified PDDs including Autism, Asberger's, Rett's Disorder, Childhood Integrative Disorder, and PDD-Not Otherwise Specified Addresses multiple issues relating to PDDs including their neuropathology and psychophysiology and advances in assessment, diagnosis, and treatment Includes contributions from a leading group of researchers and practitioners from neuropsychology, neurology, psychiatry, and clinical psychology