- Prescribing Advice for GPs - https://www.prescriber.org.uk -

Prevalence of autism appears stable

The NHS Information Centre has issued a press release and published the results (PDF) of a study that aimed to assess the prevalence of autism spectrum disorders (ASD) among adults in England. This study has been reported in the general media (BBC).

Previous studies have reviewed prevalence of autism, including Asperger syndrome, in children but little was known about prevalence in adults. It has been theorised that rates of autism in older people may decline due to recovery or premature death. This study found a prevalence of 1% among adults which is approximately the same as the rate for children. It was also noted that prevalence rates were approximately the same across all age groups.

The press release states that this latter finding "fails to support suggestions of a link between the mumps, measles and rubella (MMR) vaccine and the condition". MMR was introduced in 1990/91 so it would be expected that the prevalence of autism would be higher among children if there were a link. However, this conclusion is based upon a small sample size and the age group bands used are wide (16-44, 45-74 and 75+).

Action: These results are encouraging and are the first data assessing autism rates among adults. While these results do not support a link between MMR use and development of autism they do not conclusively disprove a link either. Additional research into autism rates in adults would be useful.