In the first study of its kind, scientists have used extensive data to identify that adults with attention-deficit/hyperactivity disorder (ADHD) have a significantly lower life expectancy than their neurotypical peers. It's complex, much like the condition, but this unprecedented research should serve as a wake-up call to governments and medical professionals across the globe.
The new study out of University College London (UCL) assessed anonymized data from 30,029 UK adults with diagnosed ADHD, and compared it with 300,390 participants without the neurodevelopmental condition, and matched the information according to age, sex and healthcare access. The researchers found that men with diagnosed ADHD had 4.5 to nine years shaved off their life expectancy. Women fared even worse, with those diagnosed having their lives cut short by an estimated 6.5 to 11 years.
Overall, the study estimates that men with ADHD have an average life expectancy of 73.26 years, compared to 80.03 years for those without the condition, while ADHD women have an expected lifespan of 75.15 years, compared to 83.79 years. While this is a comparative figure based on the UK data pooled by the researchers, it is unlikely to be an isolated finding.
The study identified that fewer than one in nine adults with ADHD had received a diagnosis, suggesting that the worldwide 'official' count of around 380 million people living with the condition is grossly underestimated.
“It is deeply concerning that some adults with diagnosed ADHD are living shorter lives than they should," said study senior author Josh Stott, a professor in UCL's Psychology & Language Sciences department. “People with ADHD have many strengths and can thrive with the right support and treatment. However, they often lack support and are more likely to experience stressful life events and social exclusion, negatively impacting their health and self-esteem."
“We know from studies of traits in the community and from studies of childhood diagnosis that the rate of ADHD in our sample is just a fraction of what it should be," he added.
The shocking mortality statistics are not due to ADHD on its own, but due to the many health and lifestyle predispositions that the condition drives. But the one constant, the researchers added, is inadequate healthcare support – for both individuals who have received a diagnosis and those who have not.
“The main finding of this study that people with ADHD die sooner than people without ADHD shows the massive impact of ADHD on people’s lives," said Oliver Howes, Professor of Molecular Psychiatry, Institute of Psychiatry, Psychology & Neuroscience at King's College London. "The study is also striking in showing how few people with ADHD get a diagnosis."
The study found that adults with ADHD are significantly more likely to have one or more of 13 comorbidities, with both sexes having more than a 17% increased risk of diabetes, 27% higher risk of hypertension, double the likelihood of epilepsy and more than 10 times likely to suffer from personality disorders. Men and women are also twice as likely to develop depression.
Compared to the general population, adults with ADHD have a much higher prevalence of substance abuse, smoking, financial turmoil, unemployment, self-harm, poor sleeping habits, compulsive behaviors and housing instability. The study also revealed they were less likely to seek medical help for serious conditions such as cardiovascular disease. The researchers call this health and lifestyle combination a "ripple effect" that has a very real impact on life expectancy.
This study also highlights the difficulty in quantifying the burden of ADHD. There is, of course, no one lifestyle or health issue that can be attributed to the lower life expectancy, and many of the identified concerns overlap. Earlier research identified that while 1.9% of the US prison population has an ADHD diagnosis, estimates put this figure at somewhere between 25% and 40% for longer-term incarcerated males.
“Only a small percentage of adults with ADHD have been diagnosed, meaning this study covers just a segment of the entire community," said lead author Dr. Liz O’Nions from UCL. “More of those who are diagnosed may have additional health problems compared to the average person with ADHD.
"Although many people with ADHD live long and healthy lives, our finding that on average they are living shorter lives than they should indicates unmet support needs. It is crucial that we find out the reasons behind premature deaths so we can develop strategies to prevent these in future.”
The one constant, as the study identifies, is a healthcare system that both fails adults who have received a diagnosis and those who are unable to seek one – and this is, unfortunately, not limited to the UK population covered in the research. In the US, it's estimated nearly nine million adults have been diagnosed with ADHD, with the process costing an individual between an estimated US$500 to $1,500. Depending on insurance, medication can cost upwards of $500 a month.
Economically, it's estimated that ADHD costs the US $122.8 billion ($14,092 per adult) every year, through unemployment ($66.8 billion) and productivity loss ($28.8 billion).
Yet in the US and around the globe, access to mental health resources for adults with ADHD remains prohibitive. (However, if you use ChatGPT, I recommend adding the neueodivergent AI assistant.)
"Cultural and structural barriers operate at all levels of the healthcare system, resulting in a de-prioritization of ADHD," researchers noted in that 2021 Frontiers in Psychiatry paper. "Services for ADHD are insufficient in many regions, and problems with service provision have intensified as a result of the response to the COVID-19 pandemic."
While the study has its limitations – including a lack of diversity in the data set – it nonetheless highlights the need for more research to better understand the complex, multifaceted impacts of ADHD and how healthcare can better support people.
"ADHD is increasingly recognised as a serious condition in adults associated with poor health outcomes," said Philip Asherson, Professor of Molecular Psychiatry at King’s College London. "Services to support adults with ADHD and improve both physical and mental health outcomes lag behind those for other common conditions such as anxiety, depression, hypertension and obesity. Of particular concern are limited access to diagnosis and treatment including psychosocial support. Until this is addressed the shorter life expectancy demonstrated in this study is likely to continue.”
In Australia, the landmark 2023 Senate Inquiry into ADHD was delayed by 12 months and failed to identify or address many of the issues tabled from more than 700 submissions. Meanwhile, you don't have to look far to find ADHD skeptics online – despite scientists finding evidence pointing to its genetic heritability in recent years.
And as an adult who has been fortunate enough to navigate the complicated and expensive system to get diagnosed and receive frontline treatment (medication), which has been life-changing, nothing that's come out of this UK study is a surprise.
"Adults with diagnosed ADHD are living shorter lives than they should," the study's authors noted. "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 was published in The British Journal of Psychiatry.
Source: University College London
