Adults with attention deficit hyperactivity disorder may face a substantially higher risk of dementia or mild cognitive impairment, according to a large observational study led by the University of Pittsburgh School of Medicine.

The research involved more than 187,000 adults aged 50 and older who were enrolled in the U.S. National Institutes of Health All of Us Research Program. Investigators examined participants’ electronic health records and genetic information.

Cognitive impairment was identified in 6.7% of participants with ADHD, compared with 3.4% of those without the disorder. That represented nearly twice the observed rate before researchers accounted for other factors.

After adjusting for age, gender and other health conditions, researchers found that adults with ADHD had more than four times the risk of dementia or mild cognitive impairment. The findings were published Oct. 7 in JAMA Psychiatry.

The researchers stressed that the study showed an association and could not establish that ADHD causes dementia. The observational design does not determine whether the neurodevelopmental disorder directly increases the risk of cognitive decline.

“This doesn’t prove that ADHD causes dementia, but 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,” senior author Tharick A. Pascoal said in a press release.

Pascoal, an associate professor of psychiatry and of neurology at Pitt, added, “Two different kinds of evidence are pointing in the same direction.”

Genetic findings also showed a notable difference. Participants with the highest genetic susceptibility to ADHD had a 35% greater risk of dementia than people with the lowest susceptibility.

Guilherme Bauer-Negrini, a co-first author and postdoctoral associate in biomedical data science at Pitt, said combining genetic information with years of health records can reveal patterns that might not appear in a smaller or more traditional study.

“With this kind of data, we can start to investigate what may be driving this association and whether any of those factors could be modified to support healthier cognitive aging,” Bauer-Negrini said in the release.

Dr. Elizabeth Landsverk, a geriatric medicine and dementia expert who was not involved in the study, said organizational difficulties among people with ADHD could be one factor contributing to the association. Neurological differences may also play a role, she noted.

Landsverk, a California based doctor with more than 20 years of experience treating patients with Alzheimer’s and cognitive decline, said challenges with focus and organization could make navigating medical care more difficult. The study also found that people with ADHD had a 20% higher incidence of using health resources, she pointed out.

“Having just signed up for Medicare, I know that it's really complicated — if you have trouble with focusing and getting things done, you may not be able to get the resources that you need,” Landsverk told Fox News Digital. She said people may struggle to visit a doctor or manage conditions such as high blood pressure.

Distinguishing ADHD from cognitive decline can also be difficult because some symptoms may overlap, according to Landsverk. Forgetting why someone entered a room, misplacing keys or failing to recall an actress’s name could appear in either situation.

Greater concern arises when a person can no longer manage ordinary responsibilities, Landsverk said. Difficulties paying bills, handling medications, attending appointments or following through on commitments can indicate that an evaluation is needed.

Changes in judgment, mood or social behavior may be more suggestive of dementia than ADHD, she added. Anyone experiencing persistent problems with memory, focus, organization or managing everyday tasks should consider consulting an expert for an evaluation.

Although the research identified an association between ADHD and cognitive impairment, Landsverk emphasized that people can address other factors tied to overall dementia risk. She pointed to maintaining a healthy weight, avoiding smoking and excessive alcohol, and remaining physically active.

Controlling blood pressure, cholesterol and diabetes is also important, according to Landsverk. She recommended a largely plant based diet and at least 30 minutes of exercise each day, noting that physical activity can also improve mood and focus.