pervasive developmental disorder, PDD

Pervasive developmental disorders, or PDD's, all involve greater or lesser degrees of problems with social interaction and communication, language ability, and intellectual function. Initially, the diagnosis of autism was applied to children with a spectrum of disorders of communication, development and behavior. Refinement of our diagnostic abillities has led to better understanding of these puzzling conditions. Autism and its relatives are now included under the broader umbrella known as pervasive developmental disorders (PDDs), which include

autism
childhood disintegrative disorder
Rett syndrome
Asperger's syndrome
atypical autism