Overview of Autism

Autism, also called infantile autism or autistic disorder, is a lifelong disorder that causes abnormal neurological development. It is one of five pervasive development disorders (PDDs) that also include Asperger's syndrome (now classified as an autism spectrum disorder), childhood disintegrative disorder, Rett disorder, and pervasive development disorder-not otherwise specified (PDD-NOS). Autism is usually diagnosed by the age of 3.

Autism causes impaired social interaction, communication difficulties, and restricted or repetitive activities and interests. People with autism often exhibit abnormal responses to sensory stimulation (e.g., touch, sound, light), usually have moderate mental retardation, and have a higher risk for developing epilepsy. Some autistic children exhibit aggression and self-injurious behavior (e.g., head banging, biting themselves).

About half of people with an autism spectrum disorder have an average or above average intelligence quotient (IQ). Many are able to display emotion and affection and respond to their environment. Terms used to describe people with the disorder include autistic-like, autistic tendencies, autism spectrum, and high-functioning or low-functioning autism.

High-functioning people with autism spectrum disorders may have minor delays in language and development and difficulty with social interactions. They may have problems initiating and maintaining conversation and efforts may be described as "talking at"—rather than talking to—others (e.g., may talk incessantly about a favorite subject despite attempts by others to speak).

With early intervention and appropriate treatment, many autistic people are able to learn and function productively. There is no cure for the disorder and some people with autism spectrum disorders require lifelong care.

Incidence & Prevalence of Autism

According to the Centers for Disease Control and Prevention (CDC) in March 2014, autism spectrum disorders affect 1 in 68 children in the United States. It's estimated that the overall prevalence increases by about 10–17 percent each year. Autism spectrum disorders occur almost 4.5 times more often in boys.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 01 Mar 2000

Last Modified: 27 Mar 2014