ADHD in adulthood vs. dementia

“In contrast,” said Dr. Callahan, “dementia is a neurodegenerative condition, meaning it is a result of a decline/change in brain health that was previously [healthy].”

“[ADHD] is not a progressive condition, unlike MCI [mild cognitive impairment] or dementia,” Dr. Golimstok told MNT. “It does not impact daily living activities to the same extent as dementia and to a lesser degree, MCI.”

Specializing in dementia, Dr. Sara Becker, postdoctoral associate at the University of Calgary, who was not involved in the study, added, “While both disorders present with cognitive deficits, especially in the areas of attention — inattentiveness, difficulty sustaining or dividing attention — their presentation and timing is different.”

ADHD as a risk factor for dementia

Whether ADHD is adult-onset or not, its association with dementia remains to be explained.

Dr. Callahan noted that “some experts have suggested genetic factors in ADHD may increase susceptibility to later-life dementia — for example, relating to dopamine signaling.”

Dr. Becker highlighted that “[I]t is not symptoms of ADHD, per se, that increase [the] risk of dementia, but more factors associated with having ADHD.”

She cited “a landmark” 2020 studyTrusted Source by the Lancet Commission that identified twelve modifiable risk factors associated with the development of dementia. Adult ADHD is associated with some of these.

Dr. Becker presented some examples. Low educational attainment is a risk factor for dementia associated with people who have ADHD. In addition, she noted that depression—another dementia risk factor—often accompanies ADHD in adults.

“Lastly, people with ADHD are also more likely to smoke, have high blood pressure, or be classified as obese, all of which are factors that increase dementia risk by worsening their vascular health,” she pointed out.

Dr. Callahan noted that her team is currently investigating this connection.

Do ADHD medications affect dementia risk?

Other experts have suggested that ADHD medications may increase dementia risk, although the current study finds otherwise, said Dr. Callahan.

The study’s lead author, Dr. Stephen Z. Levine, pointed out, “There is no approved ADHD medication for dementia; any such practice would be off-label… and not evidence-based.”

“Studies are warranted to validate such a practice because of the possible benefits and harms (e.g., cardiovascular risks) that may be associated with prescribing ADHD medications for dementia,” he told MNT.

How does ADHD affect dementia risk?

According to the authors of the study, previous investigations of adult ADHD and dementia have been inconclusive and inconsistent, and they intended to resolve some of the many lingering questions.

Dr. Golimstok lauded the new study’s large sample size and long follow-up time, saying it does further confirm the connection between adult ADHD and dementia.

However, he expressed concern that the study did not identify the symptoms of ADHD that are associated with dementia.

“The study does not clarify the type of dementia associated with ADHD, nor can it determine whether ADHD in adults is a risk factor or part of an extended prodromal [preliminary] phase of the degenerative disease.”
— Dr. Angel Golimstok

Dr. Becker described the study as “a great step toward examining, in particular, the different factors associated with ADHD that increase their risk of dementia.”

“By incorporating a large number of covariates (which have been overlooked in a few research studies) we become more able to clearly see the direct effect of ADHD on dementia risk,” she said.

“This study helps to clarify that the association is not always black and white, but that we need more research to examine, for example, sex differences or differences in types of dementia (early onset versus late onset), and clarify whether there might be specific risk factors that can (possibly) define one at-risk group of people with ADHD,” Dr. Becker added.