Men with a diagnosis of ADHD die seven years sooner, on average, than similar people without, while for women the life expectancy gap is almost nine years, the first study of its kind has revealed.
Attention deficit hyperactivity disorder can cause difficulties in concentration and problems with impulsiveness, although people with ADHD do not necessarily experience both. While estimates vary, studies suggest 3-4% of adults worldwide have ADHD.
Now researchers have revealed people diagnosed with the disorder tend to have shorter lives.
“For this group of people, they have a reduction in life expectancy that is significant, on average, and is disconcerting,” said Prof Joshua Stott, a senior author of the research from University College London.
While a previous study suggested people with ADHD had a lower estimated life expectancy, this was not based on recorded deaths.
In contrast, the new study used primary care data from more than 9 million adults across the UK, from 2000 to 2019, to explore whether ADHD was indeed associated with a shorter life.
In particular, the team looked at records for 30,039 adults with a diagnosis of ADHD, and compared them with 300,390 participants without, but who were similar in terms of age, sex and primary care practice.
The results reveal that males with a diagnosis of ADHD had a life expectancy 6.8 years shorter on average than those without, while females with a diagnosis of ADHD had a life expectancy 8.6 years shorter on average than those without.
While Stott added it was unlikely that ADHD was a direct cause of the lower life expectancies, he said there were a number of possible explanations for the findings, noting people with ADHD were more likely to have mental health problems and might experience more difficulties accessing the healthcare they needed, while lifestyle factors could also play a role.
“We know that people with ADHD have higher suicide rates unfortunately,” Stott said. “They are also more likely to engage in risky behaviours like smoking, drinking and actually binge eating probably as well.”
Stott added the figures for life expectancy applied only if the status quo for people with ADHD did not change.
However, the team cautioned the study might overestimate the life-expectancy gap for people with ADHD overall – as adults with a diagnosis might be more likely to have either mental health or neurodevelopmental conditions or both – while the reasons for the link between ADHD and a shorter life required further research.
The study, published in the British Journal of Psychiatry, also raises concerns around under-diagnosis of ADHD, with the authors noting just 0.32% of adults in the study had a diagnosis. This, they said, was about one in nine of the likely true number of people with ADHD based on population-based surveys.
Oliver Howes, a professor of molecular psychiatry at King’s College London, who was not involved in the work, said the study showed the big impact of ADHD on people’s lives, and how few people with ADHD got a diagnosis, although he cautioned the study did not look at when ADHD was diagnosed in relation to other medical problems, or the impact of treatment.
“These findings highlight the need for much more investment in mental health services so people can get the help they need,” he said.
