Adult ADHD Diagnosis Linked to Earlier Death

A diagnosis of attention deficit-hyperactivity disorder (ADHD) in adults was associated with a 7-year reduction in life expectancy, on average, compared to the general population, findings from a large study show. 

Compared with peers without ADHD, males with ADHD in the matched retrospective UK study died an estimated 7 years earlier, and females with the diagnosis died around 9 years earlier. 

“We believe that this is unlikely to be because of ADHD itself and likely caused by modifiable factors such as smoking, and unmet mental and physical health support and unmet treatment needs,” the authors wrote, adding “The findings illustrate an important inequity that demands urgent attention.” 

The findings were published online January 23 in The British Journal of Psychiatry. 

Consequences of Impaired Executive Function

Previous research has shown that adults with ADHD experience more unemployment, financial problems, contacts with the criminal justice system, and homelessness than those without the condition. 

ADHD has also been linked to a higher risk of suicide, and an earlier meta-analysis of eight studies found that people with ADHD are twice as likely as those in the general population to die prematurely.

They are also more likely to engage in risky behaviors, such as smoking, taking drugs, and smoking, investigators noted. 

To learn more about ADHD and life expectancy, investigators examined electronic medical records from 794 UK primary care practices. The analysis included data on 30,039 adults diagnosed with ADHD at any point in their lives and 300,390 matched controls. 

The primary outcome was all-cause death. In the UK, primary care offices are updated with patients’ deaths by the National Health System Personal Demographic Service.

Investigators used a Poisson model to estimate the mortality rate by single year-of-age for those with ADHD and the control group. They then used the modelled rates to estimate life expectancy at age 18 years using the period life table method as described by the Office for National Statistics. 

The median age at cohort entry for males was 18.95 years and 22.10 years for females.

Shorter Lifespans

Mortality rates were higher in the ADHD group (males, 0.83%; females, 2.22%) compared to the control group (males, 0.52%;females, 1.35%). 

Among those with ADHD, death was 1.89 times more likely in men (95% CI,1.62-2.19) and 2.13 times more likely in women (95% CI, 1.79-2.53) during follow up compared to controls.

ADHD was associated with a reduction in total life expectancy of 6.78 years in males (95% CI, 4.50-9.11) and 8.64 years in females (95% CI, 6.55-10.91).

Average age at death for the ADHD group was 73 years in men (95% CI, 71.06-75.41) and 75 years (95% CI, 72.99-77.11) in women. For the control group, average age at death was 80 years (95% CI, 79.34-80.74) for men and 84 years for women (95% CI, 83.12-84.44). 

The authors called the findings “extremely concerning,” adding that for individuals with ADHD, there are often associated mental health challenges, including substance use, smoking, or compulsive behavior that may contribute to premature death. 

“Only a small percentage of adults with ADHD have been diagnosed, meaning this study covers just a segment of the entire community,” lead author, Elizabeth O’Nions, PhD, epidemiologist at the Bradford Institute for Health Research, University College of London, said in a press release. 

“More of those who are diagnosed may have additional health problems compared to the average person with ADHD. Therefore, our research may over-estimate the life expectancy gap for people with ADHD overall, though more community-based research is needed to test whether this is the case,” she continued.

Study limitations include the lack of information about cause of death and wide confidence intervals around certain point estimates, likely due to the relatively small number of participants with ADHD. In addition, the findings are probably not generalizable to other countries, settings, or time periods, the authors wrote. 

Experts Weigh In

Several experts who were not part of the study weighed in on the findings in a statement from the UK-based nonprofit and independent Science Media Centre.

Philip Asherson, PhD, professor of molecular psychiatry at King’s College London, said the study illuminated the impact of an ADHD diagnosis on life expectancy.

While the causes of early death are not yet confirmed, he noted, ADHD has been linked to cardiovascular disease and cancer and may be linked to autoimmune and other physical health disorders. “ADHD is increasingly recognized as a serious condition in adults associated with poor health outcomes,” Asherson said. 

Of particular concern are limited access to diagnosis and treatment including psychosocial support, he said, adding, “until this is addressed, the shorter life expectancy demonstrated in this study is likely to continue.”

Also commenting on the study was Oliver Howes, PhD, MBBS, professor of molecular psychiatry, Institute of Psychiatry, Psychology & Neuroscience, King’s College London.

“The study adds to lots of other evidence that people with other mental illnesses die sooner than people without mental illness to show this for ADHD as well,” he said. 

The study’s use of a large UK database is a strength, but a limitation was that investigators were unable to study how participants’ ADHD diagnosis date was related to comorbid conditions or treatment efficacy. “More work is needed to understand what underlies the link between ADHD and premature death,” he said. 

The study did not receive specific funding. Asherson reported no relevant financial relationships.