In comparison to adults without attention-deficit/hyperactivity disorder (ADHD), adults with ADHD have a nearly three-fold increased risk of developing dementia, a Rutgers study indicates.
Michal Schnaider Beeri, head of the Herbert and Jacqueline Krieger Klein Alzheimer’s Research Center at Rutgers Brain Health Institute (BHI), coauthored the study, which was published in JAMA Network Open. It followed over 100,000 older Israelis for 17 years to see if persons with ADHD are more likely to develop dementia, including Alzheimer’s disease.
Research on adults with ADHD is scarce, despite the fact that over 3% of adults in the US suffer from the condition.
“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 Beeri, a faculty member of the Rutgers Institute for Health, Health Care Policy and Aging Research.
ADHD Symptom Monitoring
Researchers examined persons with and without ADHD, as well as the occurrence of dementia among the groups as they aged, using data from a national cohort study of more than 100,000 people who were tracked from 2003 to 2020. They discovered that the existence of adult ADHD was related to a considerably greater risk of dementia, even when other risk factors for dementia, such as cardiovascular disorders, were taken into consideration.
ADHD in adults may materialize as a neurological process that reduces the ability for them to compensate for the effects of cognitive decline later in life, researchers said.
“Physicians, clinicians and caregivers who work with older adults should monitor ADHD symptoms and associated medications,”
said senior author of the study Abraham Reichenberg, a professor at the Department of Psychiatry at the Icahn School of Medicine at Mount Sinai.
Psychostimulant Treatment
Additionally, the research suggests ADHD treatment incorporating psychostimulants may help reduce the risk of dementia in adults with ADHD as psychostimulants are known to modify the trajectory of cognitive impairment. But researchers said future studies should examine in more detail the impact of medications in patients with ADHD and how they could affect risk.
“Symptoms of attention deficit and hyperactivity in old age shouldn’t be ignored and should be discussed with physicians,”
said Stephen Levine, a professor at the School of Public Health at the University of Haifa.
Abstract
Importance Evidence that adult attention-deficit/hyperactivity disorder (ADHD) is associated with an increased risk of dementia is scarce and inconsistent, and potential sources of bias are untested.
Objective To examine the association between adult ADHD and the risk of dementia.
Design, Setting, and Participants This prospective national cohort study consisted of 109 218 members of a nonprofit Israeli health maintenance organization born between 1933 and 1952 who entered the cohort on January 1, 2003, without an ADHD or dementia diagnosis and were followed up to February 28, 2020. Participants were aged 51 to 70 years in 2003. Statistical analysis was conducted from December 2022 to August 2023.
Exposure Adult ADHD was a time-varying covariate, classified as present from the age of the first diagnosis (using the International Classification of Diseases, Ninth Revision, and the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision); otherwise, absent.
Main Outcome and Measures Cox regression models were fitted to quantify the association between adult ADHD and the risk of incident dementia with hazard ratios (HRs) and their 95% CIs unadjusted and in the primary analysis, using inverse probability weights, adjusted for 18 sources of potential confounding. In 14 complementary analyses, subgroup and sensitivity analyses were implemented.
Results At the beginning of the follow-up, the sample of 109 218 participants had a mean (SD) age of 57.7 (5.5) years, 56 474 participants (51.7%) were female, and 52 744 (48.3%) were male. During follow-up, 730 participants (0.7%) received a diagnosis of adult ADHD, and 7726 (7.1%) received a diagnosis of dementia. Dementia occurred among 96 of 730 participants (13.2%) with adult ADHD and 7630 of 108 488 participants (7.0%) without adult ADHD. In the primary analysis, compared with the absence of adult ADHD, the presence of adult ADHD was statistically significantly (P < .001) associated with an increased dementia risk (unadjusted HR, 3.62 [95% CI, 2.92-4.49; P < .001]; adjusted HR, 2.77 [95% CI, 2.11-3.63; P < .001]). Twelve of the 14 complementary analyses did not attenuate the conclusions based on the results of the primary analysis. There was, however, no clear increase in the risk of dementia associated with adult ADHD among those who received psychostimulant medication, and evidence of reverse causation was mild.
Conclusions and Relevance In this cohort study of individuals born between 1933 and 1952 and followed up in old age, adult ADHD was associated with an increased risk of dementia. Policy makers, caregivers, patients, and clinicians may wish to monitor reliably for ADHD in old age.
Reference:
- Levine SZ, Rotstein A, Kodesh A, et al. Adult Attention-Deficit/Hyperactivity Disorder and the Risk of Dementia. JAMA Netw Open. 2023;6(10):e2338088. doi:10.1001/jamanetworkopen.2023.38088