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Calls to Action

Mortality and Cause of Death

in Autism Spectrum Disorders
September 21, 2009

In 2008, a Danish team of researchers published a revealing scientific study documenting the mortality rate of individuals with Autism Spectrum Disorders (ASD). Following over 340 individuals from adolescence to adulthood, this study confirmed earlier results showing that the rate of death is twice as high among individuals with ASD as the general population. Additionally, this higher than average mortality risk among individuals with autism was found to be even higher among females when compared to males, although it was noted that sex differences need to be further explored. The authors also investigated the relationship between mortality rate and IQ and found no increased risk of death between individuals with an IQ < 70 (severe to moderate mental retardation) and those with an IQ > 70.

This study also examined specific causes of death to determine if some causes were more common than others. The authors discovered that epilepsy was present in 8 of the 26 individuals with ASD that died during the study period and in 4 cases, epilepsy was noted as the underlying cause of death. Other common causes of death included infectious diseases, diseases of the circulatory system, and unnatural causes such as suffocation and drowning. Interestingly, it was further observed that common causes of death differed between younger and older subjects in the study. For instance, it was noted that epilepsy-related deaths were more common among relatively young individuals. Additionally, diseases of the circulatory system were common causes of death among older individuals, while deaths due to unnatural causes were more likely among younger individuals with ASD.

With new insight into the elevated mortality and common causes of death among patients with ASD, there is now a greater ability to evaluate preventive measures and medical care practices that may help ensure the well-being of these individuals. By noting that epilepsy and infectious disease may be the most common causes of death among individuals with ASD, professionals can direct their focus on preventing and/or treating these conditions. Furthermore, parents and caregivers should be aware that their loved ones with ASD are at increased risk of accidental deaths due to drowning and suffocation, particularly younger individuals. Increased understanding of the most common causes of death can help parents and professionals focus on reducing associated risks and ultimately the rate of mortality among individuals with autism.

Mouridsen SE, et al. Mortality and causes of death in autism spectrum disorders: an update. Autism. 2008 Jul;12(4):403-14.

Shavelle RM, et al. Causes of death in autism. J Autism Dev Disord. 2001 Dec;31(6):569-76.