We estimate that 11 in every 1,000 people (1.1% of the population) are on the autism spectrum. This means if you are a GP with a list size of 2,000 people, you're likely to have around 22 people on the autism spectrum on your list.

Read on for information and advice about autism, or go straight to our checklist for GPs.

What is autism?

  • Autism is developmental – affecting social and communication skills
  • Autism is lifelong
  • Autism is a spectrum condition which includes Asperger syndrome and PDA
  • Autism is wide-ranging – some people have accompanying learning disabilities while others have average or above average intelligence. Similarly, linguistic skills range from those who are preverbal to those who display complex, grammatically correct speech.
  • Autism is part of the group of disorders known as pervasive developmental disorders (PDDs) in the World Health Organisation’s International Classification of Diseases.

Diagnostic statistics suggest autism affects more boys than girls, however there is ongoing research in this area. Find out more about gender and autism.

Read full definitions of the autism spectrum in general, or Asperger syndrome and pathological demand avoidance (PDA) in particular.

Where does Asperger syndrome fit in?

Autism and Asperger syndrome are all part of the same autism spectrum. People with Asperger syndrome tend to have average or above average intelligence and generally have fewer problems with language. Read our short guide to adults with Asperger syndrome for GPs.

Additional disorders

The presence of additional disorders, such as epilepsy, sensory impairments, Down's syndrome, or other physical disabilities can affect the clinical picture.


The precise cause of autism is not known, although research indicates that genetic factors are important. In some cases autism spectrum disorders may also be associated with various conditions affecting brain development, such as maternal rubella, tuberous sclerosis or post-encephalitic states but the frequency of such findings remains uncertain.

Strategies and approaches

Behaviour management techniques have proved a valuable way of supporting people with autism and reducing problematic behaviours such as temper tantrums, phobias, sleep problems, aggression or self-injurious behaviours.

It is important to remember, however, that people on the autism spectrum will not respond in the conventional way to standard behaviour modification techniques. They will not, for example, understand the rewards of social reinforcement.

However, behavioural treatment, usually carried out by a clinical psychologist, can be a useful intervention. Sometimes community psychiatric nurses or other mental health professionals may also have developed expertise in this area.

Psychotropic drugs may be indicated for the treatment of a specific mental disorder. Whilst it is preferable to avoid drugs in the treatment of longstanding maladaptive behaviours they are sometimes necessary and can prove beneficial.

Find out more about strategies and approaches for supporting people on the autism spectrum.

Screening for autism

There are various tools available for screening for autism. Read about the screening tools available on the Research Autism website. 

The Royal College of GPs also have some guidance available about screening tools among other topics.

There are several absolute indications for immediate further evaluation (view research source). These are:

  • no babbling by 12 months
  • no gesturing (pointing, waving, bye-bye, etc) by 12 months
  • no single words by 16 months
  • no two-word spontaneous (not just echolalic) phrases by 24 months
  • any loss of any language or social skills at any age.

A checklist for GPs

  1. Consider screening all language-delayed children for autism.

    Parents of children with autism often report dissatisfaction with the diagnostic process. On average parents first become concerned when their child is around 18 months of age and first seek help when he or she is about two years. However, it often takes years before a diagnosis is made. Not infrequently parents are reassured about their initial concerns only to discover later that their child has autism.
  2. Make reasonable adjustments.

    People with autism find changes in routine difficult and may be stressed by having to break their routine to visit their GP or health visitor. Some are hypersensitive to noise and others fearful of crowds. They often have difficulty waiting their turn. A waiting room can therefore be an extremely stressful environment.

    Making allowances of early or later appointment times when the waiting room is less busy, allowing them to wait in a separate area and to book a slot when you are more likely to be on schedule (such as first thing in the morning) can help. If there are delays, provide clear information so they know what to expect.
  3. Be aware of the complex impairment of communication in autism and Asperger syndrome.

    People on the autism spectrum are likely to have difficulty understanding what is said to them. Even those with seemingly good expressive speech are likely to struggle with non-literal communications such as figures of speech, sarcasm or jokes. 
  4. Communicate using factual language and avoiding abstract terms, supporting verbal information with visual information. The Show me where tool could help people to indicate where they have pain or discomfort or help you to explain which part of the body you are going to examine or treat.. Allow extra time for people to answer questions and be aware that making eye contact is sometimes difficult. Be aware what you say may be taken literally. For example, being prescribed 'medicine' might cause a refusal of medication in tablet form from the pharmacist. 
  5. Be aware of the effects of hyper- and hyposensitivity

    Some people with autism have an altered sensitivity to pain. They may be oblivious to injury, or alternatively, experience the texture of certain fabrics as painful. The possible implications for medical consultations are obvious.
  6. Refer to support professionals where appropriate, giving consideration to diet, dental health, sleep and challenging behaviour.
  7. Be sensitive to the individual or families' needs.

    Listening to the parents' story with attention and interest gives a real understanding of the child and establishes a good relationship with the family. Remember that the terminology can be complex and confusing for parents.
  8. Consider putting parents in touch with a local support group or The National Autistic Society.

    The first point of contact for parents is the NAS Autism Helpline which provides a written and phone enquiry service.


Adolescence and transition to adult life

Not surprisingly, adolescence can be an especially testing time for people with autism and for their families.

In addition to the developmental changes associated with puberty, some people on the autism spectrum begin to develop a painful awareness of their difficulties, which can result in depression or behavioural problems.

About one third of people with autism develop epilepsy with an onset of seizures in adolescence occurring in a significant proportion. Many adolescents, however, will only ever have one or two seizures and medication should not, therefore, be prescribed immediately.

Many autistic adults develop mental health problems including anxiety, depression and OCD. If they don't have an autism diagnosis, this can sometimes result in their autism being missed.

Autism results in lifelong disability for those affected individuals. Follow-up studies have shown that the majority continue to suffer problems as adults and few manage to live independently. For most, therefore, there will be a continuing need for social support and some will also require input from mental health professionals.

Unfortunately, professionals working within adult services have often been unfamiliar with the problems of autism. It is hoped that this is changing as awareness of the disorder increases.

Find out more