ADHD linked to more than fourfold higher risk of later cognitive impairment in large US study

A study led by the University of Pittsburgh and published on 7 October 2026 in JAMA Psychiatry links adult ADHD to a much higher risk of dementia or mild cognitive impairment later in life.

What the researchers did

They analysed health records and genetic data from more than 187,000 adults aged 50 and older in the US National Institutes of Health’s All of Us research programme.

Findings

• 6.7% of participants with ADHD developed dementia or cognitive impairment, compared with 3.4% of those without ADHD.
• After adjusting for age, sex and other health conditions, people with ADHD had more than four times the risk over time.
• People with the highest genetic risk score for ADHD — whether or not they had a diagnosis — had a 35% greater chance of dementia than those with the lowest score.
• Among people who developed cognitive impairment, those who also had ADHD reported worse mental health and quality of life and used about 20% more health care in the following year.
• The link held even when at least eight years separated the ADHD diagnosis from the onset of cognitive problems, which makes it less likely that early dementia was simply mistaken for ADHD.

Limitations

This is an observational study based on medical records, so it shows an association, not cause and effect. “This doesn’t prove that ADHD causes dementia,” said senior author Tharick Pascoal. It is not known whether ADHD medications or better cardiovascular health change the risk. People with ADHD who are worried about memory should talk to their doctor.