A pervasive neurological disorder that is observable in early childhood and persists throughout the lifespan, characterised by atypical communication, language development, eye contact, and sensory experiences.
(now medically obsolete) A diagnosis involving a pathological tendency to engage in self-centered fantasy thinking, historically considered a symptom of insanity and/or schizophrenia.
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.