Pervasive Development Disorder-Not Otherwise Specified (PDD-NOS)

One of the three Autism Spectrum Disorders (ASD) and one of the five conditions in the category of Pervasive Developmental Disorders (PDD) as outlined in the DSM-IV. PDD-NOS is characterized by severe and persistent impairments in social interaction skills, communication skills, with stereotypical behaviour, but do not meet the criteria for another PDD disorder.