Adults diagnosed with attention-deficit/hyperactivity disorder have shorter life expectancies compared to the general population, with males losing approximately 7 years and females losing nearly 9 years of life, according to findings from a UK-based study examining mortality data in this population.

Researchers—who published their findings in The British Journal of Psychiatry—analyzed data from 792 general practices covering over 9.5 million people between 2000 and 2019. The study identified 30,039 adults with diagnosed attention-deficit/hyperactivity disorder (ADHD) and matched them with 300,390 controls.

"Adults with diagnosed ADHD are living shorter lives than they should," first study author Elizabeth O'Nions, PhD, and colleagues wrote. "We believe that this is likely caused by modifiable risk factors and unmet support and treatment needs in terms of both ADHD and co-occurring mental and physical health conditions."

The study found males with ADHD had a life expectancy of 73.26 years compared to 80.03 years for controls, representing a reduction of 6.78 years (95% confidence interval [CI] = 4.50–9.11 years). For females, life expectancy was 75.15 years versus 83.79 years, a reduction of 8.64 years (95% CI = 6.55–10.91 years).

Mortality rates increased exponentially with age. Males with ADHD were 1.89 times (95% CI = 1.62–2.19) more likely to die during follow-up compared to controls. Females with ADHD had a 2.13 times (95% CI = 1.79–2.53) higher mortality risk compared to controls.

The researchers found that adults with ADHD had significantly higher rates of various comorbidities at baseline compared to controls, including:

• Epilepsy (males: odds ratio [OR] = 3.03, 95% CI = 2.8–3.29; females: OR = 3.49, 95% CI = 3.01–4.04)
• Severe mental illness (males: OR = 6.70, 95% CI = 6.08–7.38; females: OR = 8.35, 95% CI = 7.15–9.76)
• Self-harm/suicide (males: OR = 5.80, 95% CI = 5.51–6.10; females: OR = 4.83, 95% CI = 4.49–5.18)
• Current smoking (males: OR = 2.67, 95% CI = 2.60–2.75; females: OR = 2.15, 95% CI = 2.04–2.27).

"At present, there is a dearth of specialist services to support adults with ADHD in the UK," the authors noted. "A population-based study revealed that those with ADHD characteristics were more likely than comparison adults to have accessed support, or to have requested a particular treatment that they did not subsequently receive."

The study represents only diagnosed cases, which authors estimate comprise approximately one in nine actual ADHD cases based on population surveys. They emphasized these findings highlight "an important inequity that demands urgent attention."

This research marks the first use of mortality data to calculate life expectancy in adults diagnosed with ADHD using the life table method. The authors noted that while previous studies have shown increased mortality risk, none had specifically quantified years of life lost in this population.

Limitations of the report include inability to determine specific causes of death and possible selection bias, as diagnosed cases may overrepresent individuals with more severe presentations who came into contact with specialist services.

Full disclosures can be found in the study.