The study, published in the British Journal of Psychiatry, found people with autism die on average 18 years earlier than peers without the condition. The study showed people with autism and intellectual disability die a shocking 30 years earlier, at about age 39.
For people with autism alone, the main cause of death was suicide. For people with autism and intellectual disability, the leading cause was epilepsy.
Swedish researchers analyzed data from two Swedish population-based registers. They included over 27,000 people with autism, of whom about 6,400 had intellectual disability, and more than 2.6 million people without autism matched for age, gender and county of residence.
On average, people with autism have a 2.5 times higher risk of premature death. Adults with autism and no intellectual disability were nine times more likely than peers to end their lives, with women being at particular risk.
I was unable to get a copy of the full study, but news reports say the underlying factors contributing to premature death may include restricted diet, less exercise, and increased social isolation, anxiety and depression. In addition, people with autism may struggle to explain their health symptoms, causing a delay in diagnosis and treatment.
This mirrors a British inquiry in 2013 that found women with intellectual disability (but not autism) died 20 years earlier on average than the general population and men with developmental disability (but not autism) died 13 years earlier.
British researchers said more than a third of the deaths studied could have been avoided with good health care—more than three times the proportion avoidable in the general population.
"Significantly more people with learning disabilities experience difficulties in having their illnesses diagnosed and treated," lead investigator Pauline Heslop says.