Attention deficit hyperactivity disorder (ADHD) is linked to criminality, accidents, and substance misuse, all of which may increase your risk of an earlier-than-usual death. However, a new Danish study finds that even when such related issues are excluded a diagnosis of ADHD may influence your life span profoundly. People with ADHD are twice as likely to die prematurely, the researchers say, and women with the disorder have a higher relative risk than men.

“Although no single study can be definitive, this one comes close,” wrote Dr. Stephen V. Faraone, Director of Medical Genetics Research at SUNY Syracuse, in a published comment on this research. “The sample was large — 1.92 million people, of whom 32,061 had ADHD — and the follow-up was long, with little missing data.”

Genes or Environment?

ADHD is a behavioral condition that makes focusing on everyday requests and routines challenging. According to the American Psychological Association, people with this condition typically have trouble getting organized, staying focused, making realistic plans, and thinking before acting. Scientists say genes play a substantial role in ADHD. In twin studies of ADHD, for instance, researchers estimate 76 percent of all ADHD cases are a result of inherited genes, while the environment accounts for the remaining 24 percent. However, since the environment influences genes, both are entwined and considered significant as contributing factors.

To understand whether ADHD is linked to premature death, researchers looked at data in the Danish national registers for a period of over 32 years. They followed up 1.92 million individuals, including 32,061 with ADHD, from their first birthday through 2013. After adjusting for factors that influence lifespan — including sex, maternal and paternal age — the team discovered people with ADHD are twice as likely to die early. They also found girls and women with ADHD have a higher relative risk of premature death compared with boys and men with the disorder.

“The excess mortality in ADHD was mainly driven by deaths from unnatural causes, especially accidents,” wrote the authors in the conclusion to their study. In fact, more than half of such deaths were caused by accidents, including car crashes.

Emphatically, the researchers stated that, while relative risk of premature death is increased, the absolute risk is low. This means few people with or without ADHD die early overall. The team highlighted one unusual finding: People diagnosed as adults had a higher risk of premature death than those diagnosed while still a child or teen. For this reason, the researchers suggest early screening and treatment for this mental disorder.

Source: Dalsgaard S, Otergaard SD, Leckman JF, et al. Mortality in children, adolescents, and adults with attention deficit hyperactivity disorder: a nationwide cohort study. The Lancet. 2015.