Book excerpt: Now in a fully updated Third Edition, The Handbook of Autism and Pervasive Developmental Disorders has, since the first edition, become the most influential reference work in the field of autism and related conditions. In two volumes, this invaluable reference provides a comprehensive review of all information presently available about these disorders, drawing on findings and clinical experience from a number of related disciplines such as psychiatry, psychology, neurobiology, pediatrics, etc.