Autism includes atypical brain development which often becomes apparent in behavior and social development before a child is three years old. It can be categorized by impairments in social interaction and communication as well as restricted interests and stereotyped behavior and the characterization is independent of any underlying neurological defects. Other characteristics include repetitive-like tasks seen in behavior and sensory interests. This article uses the terms autism and ASD to denote classical autism and the wider dispersion of symptoms and manifestations of autism respectively.