Autism is a brain development disorder characterized by impairments in social interaction and communication, and restricted and repetitive behavior, all exhibited before a child is three years old. These characteristics distinguish autism from milder autism spectrum disorders (ASD) such as Asperger syndrome. ...

Autism is a brain development disorder characterized by impairments in social interaction and communication, and restricted and repetitive behavior, all exhibited before a child is three years old. These characteristics distinguish autism from milder autism spectrum disorders (ASD) such as Asperger syndrome.

Autism affects many parts of the brain; how this occurs is poorly understood. Parents usually notice signs in the first year or two of their child's life. Early intervention may help children gain self-care and social skills, although few of these interventions are supported by scientific studies. There is no cure. With severe autism, independent living is unlikely; with milder autism, there are some success stories for adults.

Autism is one of the five pervasive developmental disorders (PDD), which are characterized by widespread abnormalities of social interactions and communication, and severely restricted interests and highly repetitive behavior. Of the other four PDD forms, Asperger syndrome is closest to autism in signs and likely causes; Rett syndrome and childhood disintegrative disorder share several signs with autism, but may have unrelated causes; PDD not otherwise specified (PDD-NOS) is diagnosed when the criteria are not met for a more specific disorder. Unlike autism, Asperger's has no substantial delay in language development.

The manifestations of autism cover a wide spectrum, ranging from individuals with severe impairments--who may be silent, mentally disabled, and locked into hand flapping and rocking--to less impaired individuals who may have active but distinctly odd social approaches, narrowly focused interests, and verbose, pedantic communication.

Characteristics

Autism is distinguished by a pattern of symptoms rather than one single symptom. The main characteristics are impairments in social interaction, impairments in communication, restricted interests and repetitive behavior. Other aspects, such as atypical eating, are also common but are not essential for diagnosis.

Social development

People with autism have social impairments and often lack the intuition about others that many people take for granted. Less eye contact, smile less, respond less to their own name and to, difficulty making and maintaining, communication.

About a third to a half of individuals with autism do not develop enough natural speech to meet their daily communication needs.