What is Autistic Spectrum Disorder?

The term Autistic Spectrum Disorder covers a wide range of conditions, including autism and Asperger syndrome that are characterized by impaired social interaction, communication difficulties and restricted, stereotypical and repetitive activities and interests. Autistic spectrum disorder (ASD) is a developmental disorder that is usually diagnosed in childhood. Children and adults with this condition have a wide range of intelligence. Some (up to 75%) have learning disabilities, while others have normal or above average intelligence and intellectual capacity. Those in the latter groups are described as having high functioning autism.

The causes of autistic spectrum disorder are not clearly understood but include genetic factors, chromosomal abnormalities, complications of pregnancy and child birth leading to organic brain damage. The condition is associated with epilepsy in up to 30% of cases.

People with high functioning autism are likely to have average or above average intelligence, and includes people who are referred to as having Asperger syndrome. In this group people have difficulties with social interaction, language and a restricted range of activities and interests. They may have problems both in using and understanding language. Their speech is often well developed and fluent but language may be used in unusual ways.

Prevalence and Incidence

Autistic spectrum disorders are four times more common in males than females. An increase in the number reported cases of autism has been noted over recent years in the UK. This is likely to be related to improved awareness and diagnosis of the condition. Recent research shows a prevalence of 116 cases per 10,000, or a total of over half a million individuals.

Amended April 2008