The range of conditions classified as pervasive developmental disorders, generally held to include autistic disorder, Asperger syndrome, and pervasive developmental disorder - not otherwise specified (PDD-NOS). Also includes childhood disintegrative disorder and Rett syndrome.

plural of autism spectrum disorder

(psychology, pathology) A disorder involving any of a range of psychological conditions, all characterized by abnormal social interaction and communication, restricted interests, highly repetitive behaviour, and eccentricity.