Study: Adults with ADHD at higher risk of developing dementia 

Adults diagnosed with attention-deficit/hyperactivity disorder have a nearly three times greater risk of developing dementia than those without ADHD, according to a study released Tuesday.

Researchers followed nearly 110,000 Israeli residents between the ages of 51 and 70 from 2003 to 2020 to determine a potential link between adult-onset attention-deficit/hyperactivity disorder and dementia as they age.

The researchers found that adult ADHD diagnoses were associated with a 2.7-fold increased dementia risk, even when other risk factors were taken into account, such as cardiovascular conditions.

"This study suggests that adult ADHD is associated with an increased risk of dementia and warrants reliable assessment in adulthood," said the study, which included researchers from New York and New Jersey.

An estimated one in eight Long Island seniors has Alzheimer’s disease — the most common type of dementia — and Nassau County’s rate is in the top 15% of counties nationwide, according to a study released in July by the Chicago-based Alzheimer’s Association. About 31,300 seniors in Nassau and 30,500 in Suffolk have the disease, those researchers estimated.

While more than 3% of the adult population in the United States has ADHD, there is limited research on the group, with most studies focused on children with the neurodevelopmental disorder. Nearly 10% of U.S. children, ages 3 to 17, have been diagnosed with ADHD, according to the Centers for Disease Control and Prevention.

ADHD in adults can materialize as a neurological process that reduces their ability to compensate for the effects of cognitive decline later in life, the researchers said.

“Physicians, clinicians and caregivers who work with older adults should monitor ADHD symptoms and associated medications,” said Abraham Reichenberg, a professor at the Icahn School of Medicine at Mount Sinai in Manhattan and a senior author of the study.

Researchers also found that the use of certain medications for treatment of attention-deficit/hyperactivity disorder, such as Ritalin, can reduce the risk of dementia in adults with ADHD, particularly if used at a young age,

“By determining if adults with ADHD are at higher risk for dementia and if medications and/or lifestyle changes can affect risks, the outcomes of this research can be used to better inform caregivers and clinicians,” said Michal Schnaider Beeri, director of the Herbert and Jacqueline Krieger Klein Alzheimer’s Research Center at Rutgers Brain Health Institute, and a co-author of the report.

But Dr. Jeremy Koppel, co-director at the Litwin-Zucker Center for the Study of Alzheimer’s disease at the Feinstein Institutes for Medical Research at Northwell Health, said the study can be easily misinterpreted.

Koppel believes the typical symptoms exhibited by adults with ADHD — forgetfulness, disorganization, misplacing things and carelessness — are instead likely the early neuropsychiatric symptoms that develop before a formal dementia diagnosis. He said individuals who exhibit those symptoms later in life should seek neuropsychological testing.

"Some might say, 'ADHD as a disease increases the likelihood of developing dementia and if you treat it, that goes away. So we better treat a bunch of ADHD [cases],'" said Koppel, who is running a study looking at psychiatric symptoms as risk factors for dementia. "I don't think that's what happened here … I don't think that we're under-diagnosing ADHD. And I don't think that treating ADHD is going to prevent any dementia."

Melissa Katz, senior director of programs and services at the Long Island Alzheimer’s and Dementia Center in Westbury, said she's seen many seniors who were prescribed medications typically used for ADHD during the early stages of Alzheimer's.

"It's hard to differentiate the symptoms of ADHD from the symptoms of dementia because there's an overlap there," Katz said. 

Dr. Aaron Pinkhasov, a professor and chair of the department of psychiatry at the NYU Grossman Long Island School of Medicine, said the report once again shows the need for cognitive assessments earlier in life.

"One of the main problems that I see, and it's well known, is by the time patients come to our attention they're so far gone," Pinkhasov said. "They've already used up their reserve cognitive capacity."

By Robert Brodsky

robert.brodsky@newsday.com@BrodskyRobert

Robert Brodsky is a breaking news reporter who has worked at Newsday since 2011. He is a Queens College and American University alum.