A review of: Mouridsen, S.E., Bronnum-Hansen, H., Rich, B., Isager, T. (2008). Mortality and causes of death in autism spectrum disorders: An update. Autism, 12 (4), 403-414. DOI: 10.1177/1362361308091653
The issue of life expectancy and mortality rates in people with autism is a largely understudied and seldom discussed topic. Studies of mortality in people with chronic psychiatric disorders usually show higher mortality rates at all ages than what is expected in the general population. Mortality rates refer to the number of death expected up to a specific age for specific cohorts. For example, what is the expected number of death within a cohort born in year 1973 by the time they are 30?
Only a couple of studies of mortality rates in people with autism have been conducted, one in California and one Denmark. Both studies showed that the mortality rate in people with austim was more than twice as that for the general population. The present study by the Danish team intended to expand on their original findings by examining the mortality rate and causes of death among a cohort of adults with ASDs who are now in their 40s. The sample included 341 adults with various diagnoses including autism (N=118), atypical autism (N=89), childhood disintegrative disorder (N=13), and asperger’s (N=121).
The mean age for the patients was 43.4 with a range of 26 to 60. A total of 26 patients have died by 2006 (7.6%). The expected number of deaths in the general population for a similar cohort was 13.5 (3.8%). Therefore, the mortality rate in the cohort of adults with ASDs was nearly twice of what is expected in the general population. However, this effect was significantly more pronounced among women. The mortality rate for woman with ASD was 4 times higher than what is expected in the general population. Surprisingly, these effects were not moderated (reduced) by IQ, which often reflects functional capacity. That is, within the group with ASDs, the mortality rates was the same for adults regardless of their IQ. The cause of death most commonly reported among the cohort with ASDs was epilepsy.