Autistic spectrum disorders (ASD)

Autistic Spectrum Disorder (ASD) is a term used to describe a number of symptoms and behaviours which affect the way in which a group of people understand and react to the world around them.

It's an umbrella term which includes autism, Asperger syndrome and pervasive developmental disorders. All of these autistic spectrum disorders have an onset before the age of three. The cause is still unknown, although in some cases they can be passed down genetically.

People with autism can also have a learning disability, ranging from those requiring minimal support to lead an active life through to those requiring lifelong, specialist support. Recent research by the Learning Disabilities Observatory (PDF) indicates that around 20-30% of people with learning disabilities have an ASD.

Being diagnosed with Asperger syndrome does not constitute having a learning disability.

How does an autistic spectrum disorder affect people?

As a ‘spectrum disorder’, the symptoms and characteristics of autism can present themselves in a variety of combinations, ranging from extremely mild to severe. All children and adults with an ASD will have the following core symptoms in what is known as the ‘triad’ of impairments:

1. Non-verbal and verbal communication
  • People with an ASD have difficulty in understanding the communication and language of others, and in communicating themselves.
  • Many children are delayed in learning to speak and a small minority do not develop much functional speech. This does not mean they cannot communicate, as they use other methods to communicate their needs.
  • People with an ASD tend to have a literal understanding of language, so the use of metaphors such as ‘it’s raining cats and dogs’ should be avoided.
2. Social understanding and social behaviour
  • People with an ASD have difficulty understanding the social behaviour of others and can behave in socially inappropriate ways.
  • People with an ASD have difficulty empathising with others, and as a result are unable to read social contexts.
  • Children with an ASD often find it hard to play and communicate with other children, because of their difficulties with empathy.
3. Imagining and thinking/behaving flexibly
  • Children with an ASD find it difficult to engage in imaginative play, so they tend to spend more time in solitary play.
  • Children with an ASD can have an excellent memory concerning toys or activities they are passionate about. People with an ASD tend to have particular interests in specific topics or activities, which they may pursue obsessively.
  • People with an ASD often find change difficult to cope with, and have a preference for routine. They may also struggle to transfer skills to other activities.

In addition to the above 'triad', some people with an ASD are very sensitive to certain sounds, sights, tastes and textures. This can affect their responses to things like clothes, food or noise. Some people with autism may require 24-hour support, whereas others may be able to lead more independent lives.

How many people have an autistic spectrum disorder?

  • Approximately 1% of the population has an autistic spectrum condition.
  • The prevalence rate of autistic spectrum conditions is higher in men than it is in women (1.8% vs. 0.2%).
  • 60-70% of people who have an autistic spectrum condition will also have a learning disability.

Data taken from the NHS ‘Information Centre’, Estimating the prevalence of autistic spectrum conditions in adults, 2012 (PDF).