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

Pervasive developmental disorder-not otherwise specified (PDD-NOS), also called atypical autism, was considered a milder form of autism. It occurred during infancy but not identified until ages 3-4, with some but not all characteristics: social and communications impairment and stereotyped, repetitive behavior. Before DSM-5, it was placed between autistic disorder and Asperger’s syndrome. Since DSM-5, PDD-NOS is no longer used as a separate diagnosis and is now considered a less severe form on the autism spectrum.