Adults with a more severe learning disability also have a greater likelihood of having autism according to a new report published by the NHS Information Centre.

The report combines data from the Adult Psychiatric Morbidity Survey (APMS) 2007 with findings from a new study based on a sample of people with learning disabilities living in private households and communal care establishments. It aims to:

• Estimate the prevalence of autism in England, furthering previous research that suggests people with learning disabilities are more likely to have autism
• Address the fact that the APMS did not include people with severe learning disabilities

The report estimates that the prevalence of autism:

• Is 1 per cent in the general population
• Is approximately 35 per cent among adults with severe learning disabilities living in private households
• Is approximately 31 per cent among adults with mild or severe learning disabilities living in communal care establishments
• Increases with greater severity of learning disability or lower verbal IQ
• In terms of the new study that forms part of today’s report; a sample of adults from disability registers in Leicestershire, Lambeth and Sheffield, were invited to take part between August 2010 and April 2011. People were excluded from the new study if they were sufficiently able to have taken part in the APMS 2007

The overall response rate for the new survey was 20 per cent in private households (83 interviews). Sixty four per cent of communal care establishments approached took part in the study. Among these, the response rate for individual participants was 69 per cent (207 interviews).

NHS Information Centre chief executive Tim Straughan said:

While is it is important to note that these estimates are based on a study of only three areas of the country, they offer a new insight into the prevalence of autism among people with learning disabilities.

This information will be of particular importance for those who plan and provide services to support those with learning disabilities or with autism.

Estimating the Prevalence of Autism Spectrum Conditions in Adults: Extending the 2007 Adult Psychiatric Morbidity Survey. NHS Information Centre, 31 Jan 2012.