Autistic Spectrum Disorders are part of the group of Pervasive Developmental Disorders and are collectively known as ASD's. ASD's include Autism and Aspergers Syndrome.
There are other diagnostic terms used and these vary depending on the diagnostic service and criteria used. There is a lot of lobbying and support at present to change the terminology when the diagnostic criteria are reviewed in 2013. One such popular suggestion is to rename ASD as ASC: Autistic Spectrum Condition
Autism is a lifelong developmental disorder that affects individuals in a variety of different ways. There are three main areas of difficulty, often referred to as the 'triad of impairments', which are difficulty with social communication, difficulty with social interaction, and difficulty with social imagination.
Many people with autism also have a learning disability, but individuals will have varying 'degrees' of learning disability. Other conditions that are sometimes associated with autism include Attention Deficit Hyperactivity Disorder (ADHD), Dyslexia and Dyspraxia. Also, around 28% of children on the spectrum also have epilepsy. Even children who are not already diagnosed with epilepsy may begin having seizures as they reach puberty. ASD affects around 1 in 100 people in the UK, from all nationalities and backgrounds. Boys are four times more likely to have autism than girls.
The exact cause is not known but research indicates that genetic and environmental factors together are important, and may account for changes in brain development. Each person will display characteristics from the three main areas of difficulty, but the effect of each varies significantly for each person.