Adults With ADHD Show Four Times the Dementia Risk in Pitt Study of 187,000 People

A new study of more than 187,000 older Americans links adult ADHD to a much higher rate of dementia and mild cognitive impairment. The authors say it does not show that ADHD causes either one.

The research was led by the University of Pittsburgh School of Medicine and published Oct. 7 in JAMA Psychiatry. It drew on electronic health records and genetic data from adults 50 and older enrolled in the National Institutes of Health's All of Us Research Program.

What the numbers show

Dementia or mild cognitive impairment (MCI) was recorded in 6.7% of participants with ADHD, compared with 3.4% of those without it. That is nearly double the raw rate.

After the researchers adjusted for age, gender and other health conditions, adults with ADHD had more than four times the risk.

The team also looked at genetics. Participants with the highest genetic susceptibility to ADHD had a 35% greater risk of dementia than those with the lowest. According to the study summary, that held even for people without a formal ADHD diagnosis.

What the authors say it means

The researchers did not claim to have found a cause. "This doesn't prove that ADHD causes dementia," said senior author Tharick A. Pascoal, associate professor of psychiatry and of neurology at Pitt.

His argument is that two kinds of evidence agree. "Seeing the same pattern show up independently in medical records and in people's genes gives us greater confidence that the association is not simply an artifact of how ADHD gets diagnosed," Pascoal said in a Pitt press release. "Two different kinds of evidence are pointing in the same direction."

Co-first author Guilherme Bauer-Negrini, a postdoctoral associate in biomedical data science, said the size of the dataset is what makes the pattern visible. "Analyzing genetic information alongside years of health records allows us to identify patterns that might not be visible in a smaller or more traditional study," he said.

He added that the data lets researchers "investigate what may be driving this association and whether any of those factors could be modified to support healthier cognitive aging."

A skeptical read from clinicians

The diagnostic question is the main point of dispute. Adult ADHD and early dementia can look alike: trouble focusing, forgetfulness, losing track of tasks.

Dr. Agnes K. Simone, a board-certified psychiatrist in Los Angeles, laid out that concern in a post on Instagram. A 60-year-old with new attention problems, she wrote, "can easily get labeled with ADHD, and five years later get a dementia diagnosis." In her words, the study "counts that as ADHD leading to dementia. It may have been early dementia the whole time."

Simone also pointed to other limits. Medical record diagnoses are messy, she wrote. The ADHD group skewed female and more educated, which she said is not what adult ADHD usually looks like. Treatment was never studied. She described the study as showing a possible association and said people with ADHD should not panic.

The researchers' genetic analysis is their answer to the diagnostic-overlap problem. Whether it fully settles the question is not something the study's authors claim.

Possible explanations outside the brain

Dr. Elizabeth Landsverk, a California geriatric medicine and dementia specialist who was not involved in the study, offered a more practical explanation. People with ADHD often have more trouble with organization, she told Fox News Digital. That could make it harder to keep up with health issues and get to the doctor.

She also noted that the study found people with ADHD used 20% more health resources. Navigating a system like Medicare, she said, is complicated for anyone who struggles with focus.

Landsverk said neurological differences could also play a role. The study does not separate these explanations.

What remains open

The study is observational. It can show that two things occur together. It cannot show that one drives the other, as the authors themselves acknowledge.

As Simone noted, the study did not look at whether treating ADHD changes anyone's risk. Bauer-Negrini said the next step is to work out what drives the association and which factors might be modified. No follow-up study has been announced.