Some people with autism are able to live relatively independent lives but others face additional challenges, including learning disabilities, and need varying levels of support for the whole of their lives.

Broadly speaking, about half of autistic people will be at or above the normal range of intellectual ability, and about half will be below the normal range of ability. People at or above the normal range of ability are often said to have “high-functioning autism”, or to have Asperger syndrome (the two are similar but there are differences).

Autism is strongly linked to genetic factors. As our understanding of the human genome increases, we are able to identify genetic markers which may result in autism. For different conditions – for example cystic fibrosis – the genetic markers are clear. With autism, there seems to be a range of genetic markers which may produce autism, but which do not invariably produce autism. As an example, there are cases of identical twins where one twin has autism and the other does not. The current thinking, therefore, is that autism results from a combination of a genetic difference and one or more environmental factors.

Autism involves a difference in brain development. Understanding is at a very early stage, but researchers are now looking at neural pathways and at (for example) the length of neural connections, and at the differences in brain activity in response to stimuli.

How autism affects the individual can vary enormously. They may have:

  • High anxiety, probably because of reduced ability to understand the world
  • Repetitive behaviours
  • Lack of interest (for children) in playing with other children
  • Lack of understanding of facial expressions or tones of voice
  • Literal understanding of words: a person with autism may have difficulty in understanding common metaphors such as “it’s raining cats and dogs”
  • Special interests which may be obsessive.