An ADHD diagnosis between the ages of 51 to 70 is associated with a near-threefold higher risk of dementia, a cohort study of 100,000 patients suggests. 

Israeli researchers say adult ADHD could reflect a brain pathobiological process that reduces the body’s ability to compensate for the effects of later-life neurodegenerative and cerebrovascular processes. 

“Less cognitive and brain reserve may result in pathobiological processes of ADHD that, in turn, reduce compensatory abilities,” they wrote in JAMA Network Open. 

But the authors stressed the direction of the relationship was unclear and that an ADHD diagnosis could reflect the early stages of dementia’s preclinical phase.