Many analyses of autism speak as if it were only a childhood ailment and assume that parents are the main stakeholders. But most children with autism grow up to be adults with autism, and they suffer uniquely high levels of social isolation. Almost 40 percent of youth with an autism spectrum disorder never get together with friends, and 50 percent of never receive phone calls from friends. These figures are higher than for peers with intellectual disability, emotional disturbance, or learning disability. When school ends, many adults with autism have grim prospects. Though evidence is sparse, it seems that most do not find full-time jobs. Compared with other people their age, they have higher rates of depression, anxiety, bipolar disorder, and suicide attempts.
Key Points
Question Are persons with autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD) at a higher risk of dying compared with the general population?
Findings In this systematic review and meta-analysis of 27 studies, persons with ASD or ADHD had higher mortality rates than the general population. When causes of death were examined, ASD and ADHD were associated with higher mortality due to unnatural causes (eg, injury, poisoning, and other), and only persons with ASD had an increased risk of mortality from natural causes of death (eg, neurologic, respiratory system, and cancer).
Meaning Having ASD or ADHD may be associated with higher mortality risks.
From the article:
This systematic review and meta-analysis comprehensively assess for the first time, to our knowledge, the available evidence regarding the risk of mortality in persons with ASD or ADHD. We included 27 epidemiologic studies in our quantitative evaluation, 16 of which were judged to be at low risk of bias. We found that ASD and ADHD are associated with a significantly increased risk of all-cause mortality. However, the results should be interpreted with caution because there was evidence of heterogeneity between study estimates of the mortality risks. When we examined causes of death, ASD and ADHD were associated with higher mortality risk due to unnatural (external) causes, and only persons with ASD had an increased risk of mortality from natural causes of death, but the evidence was judged as only low confidence. Fewer studies exist examining the risk of mortality among first-degree relatives of persons with ASD or ADHD, to our knowledge.
Several mechanisms, including health determinants and biological pathways, have been suggested as potential factors that might explain the excess premature mortality among children and young persons with ASD or ADHD. However, establishing a causal relationship is difficult because the associations between mortality and childhood-onset developmental disorders are complex. Severe mental and behavioral disorders appear to be associated with reduced life expectancy, both in terms of mortality from external causes and mortality from other medical conditions or diseases.10,11 Findings from previous studies and reviews have suggested that children and adults with ASD/ADHD are associated with coexisting mental and neurologic conditions (such as oppositional and conduct disorders, tic disorders, epilepsy, depression, anxiety, and substance use disorders).3-5,57 As children and young persons with ASD/ADHD age, they often experience emotional and social difficulties.3-5 Some people also exhibit impulsive forms of behavior with negative impacts on their quality of life. Behaviors such as impulsivity and/or inattention can be contributing factors for injuries and unintentional incidents in children with ASD/ADHD.58,59
Previous studies16,17,49 have tested potential modifying effects of comorbidity on mortality risk for persons with ASD/ADHD. For example, Dalsgaard et al,16 Sun et al,17 and Schendel et al49 suggested increased mortality RRs in persons with ADHD or ASD with comorbid neurologic or mental conditions (eg, oppositional defiant disorder, conduct disorder, or substance use disorder). However, it should be noted that presence of ASD and/or ADHD with any distinct additional medical condition (the so-called comorbidity or multimorbidity) may be confounded by previous exposures (such as socioeconomic factors, environmental factors, and childhood abuse).60 Prevention efforts to reduce mortality in persons with ASD or ADHD may need to address the conditions that appear to mediate causes of death. While potentially preventable, reducing excess premature mortality (eg, due to external causes) can be challenging. For example, systematic screening would be advisable in health services and social care, and preventive education can be feasible in almost all circumstances. However, some persons with ADHD/ASD are often from socioeconomically disadvantaged groups/areas and are more likely to be exposed to environmental risk factors (eg, substance misuse, violence) than other populations.61-63 Similarly, studies64,65 have shown that persons with ADHD or ASD may be less likely to receive timely diagnosis and prompt care. All these factors are possible complications of ASD/ADHD, so the implication for practice is that health care professionals should recognize their importance.
