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26 February 2015 - MNT - ADHD 'doubles the risk of early death'

Markus MacGill

Having a diagnosis of attention-deficit hyperactivity disorder increases the risk of death and reduces overall life-expectancy, a large study published in The Lancet shows. It finds that people with attention-deficit hyperactivity disorder have a more than doubled risk of premature death - and that accidents are the most common cause.

The researchers, led by Søren Dalsgaard from Aarhus University in Denmark, found the relative risk of dying was much higher for women than for men with attention-deficit hyperactivity disorder (ADHD).

Not receiving a diagnosis until adulthood was also associated with higher risk.

The study was a massive cohort study with over 32 years of follow-up of almost 2 million people in the Danish national registers.

The researchers identified 32,061 individuals, with 26% being women, who had ADHD within the nationwide cohort of 1,922,248 people.

The authors calculate that "all-cause mortality rate" (death from all causes) was:

  • 5.85 for every 10,000 person-years in people with ADHD
  • 2.21 per 10,000 in people without the disorder (controls).

This difference corresponds to a twofold rise in the mortality rate ratio (MRR) in people with ADHD.

For individuals diagnosed at age 18 years or older, the increased likelihood of early death was more than fourfold compared with those without ADHD at the same age. Children diagnosed before the age of 6 years, by contrast, were at around double the risk of death compared with their healthy counterparts.

For people whose ADHD was diagnosed in adulthood, there was an MRR of 4.25, compared with 1.58 for those people diagnosed in childhood.

The authors say this "suggests that ADHD persisting into adulthood often represents a more severe form of the disorder."

Women with ADHD had a higher mortality rate (3.01) than did men with the disorder (1.93). The authors conclude:

"The interactions with age at diagnosis, sex, and comorbid conditions emphasize the importance of early identification of ADHD, especially in girls and women, and treatment of comorbid oppositional defiant disorder, conduct disorder and substance use disorder."

The authors say their study underlines the importance, particularly for females, of early diagnosis and treatment of ADHD.

They caution, however, that the risk of early death, being compared with that for healthy people, does not translate into a high number of people with ADHD dying early - the doubled relative risk of premature death translates into a small absolute risk of early death.

A professor of psychiatry's commentary article on the study in the same issue of The Lancet echoes this point. Dr. Stephen Faraone, director of child and adolescent psychiatry research at SUNY Upstate Medical University in New York, says that 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 evidenced-based treatments for the disorder."

Dr. Faraone continues:

"For too long, the validity of ADHD as a medical disorder has been challenged. Policy makers should take heed of these data and allocate a fair share of health care and research resources to people with ADHD.

For clinicians, early identification and treatment should become the rule rather than the exception."