ADHD Diagnosis May Increase Risk of Premature Death, Study Finds

A huge study using Denmark’s population and health registries found that individuals diagnosed with attention-deficit/hyperactivity disorder (ADHD) have twice the risk of premature death and a lower life expectancy than those without ADHD.

Researchers from Aarhus University looked at health records of 1.92 million people—including 32,061 with ADHD—born in Denmark from 1981 to 2011 to investigate any associations between an ADHD diagnosis and premature mortality.

Previous research has shown that an association between ADHD and other mental illnesses (such as oppositional defiant disorder and substance use disorder) is likely to increase mortality, but it was unknown whether an ADHD diagnosis itself increased risk for premature death.

Overall, 5,580 people in the study population (including 107 with ADHD) died during the study period, which ended in 2013. The fully adjusted mortality rate ratio (MRR) for the general population was 2.21 per 10,000 person-years. But the MRR was 5.85 for decedents with ADHD, wrote Søren Dalsgaard, Ph.D., of the National Centre for Register-Based Research at Aarhus University, and colleagues in The Lancet online February 26.

Women had a higher mortality rate (3.01) than men (1.93). Older patients were at greater risk of premature death. The MRR for those first diagnosed between ages 1 and 5 was 1.86 but for those diagnosed at age 17 or later, it was 4.25.

“This finding could be caused by persistent ADHD being a more severe form of the disorder,” the researchers suggested.

“[F]ailure to identify and treat ADHD in a timely manner might worsen the course of the disorder and increase the risk to enter one of the pathways to premature death,” wrote Stephen Faraone, Ph.D., a professor of psychiatry, neuroscience, and physiology at SUNY Upstate Medical University in Syracuse, N.Y., commenting on the study in The Lancet.

Comorbidities played an important role, too. A combination of oppositional defiant disorder, conduct disorder, and substance use disorder increased mortality to an adjusted MRR of 8.29, compared with those without ADHD or those comorbidities.

Cause of death was available for 79 of the 107 people with ADHD who died; 54 died from unnatural causes, including 42 from accidents.

Earlier research pointed to a higher risk of injury among children with ADHD, the researchers noted. “Similarly, other studies have noted that people with ADHD anticipate less severe results of risk-taking behaviour and have poorer skills for prevention of injuries than do peers without ADHD.”

The study adds to the medical literature emphasizing the importance of properly diagnosing and treating ADHD, Timothy Wilens, M.D., chief of child and adolescent psychiatry at Massachusetts General Hospital for Children, told Psychiatric News.

“While the risk of premature death in this age group remains low, the overall findings are a reminder for individuals with ADHD, their families, and practitioners that early identification and treatment of ADHD may help to improve overall long-term outcome, including issues of safety,” said Wilens. “Moreover, individuals with ADHD must continue to be vigilant about the increased risk for addictions as well as mishaps related to driving.”

In addition to the value of early identification, the results also suggest a need for more research on how to improve life expectancy in this vulnerable group, said Dalsgaard and colleagues.

“Although talk of premature death will worry parents and patients, they can seek solace in the knowledge that the absolute risk for premature death is low and that this and other risks can be greatly reduced with evidence-based treatments for the disorder,” added Faraone. ■