Seniors who frequently take sleeping medications may be raising their risk for developing Alzheimer's disease, a new study warns.
Sleep medications are one of the most commonly used medications in older adults, the authors say, but their frequent use may not be without harm.
Researchers found that older white adults who said they “often” or “almost always” took sleep aids had a 79% higher chance of developing dementia compared to those who “never” or “rarely” used them.
The connection was only seen among white adults, not Black participants.
In addition, “further studies are needed to confirm whether sleep medications themselves are harmful for cognition in older adults or [if] frequent use of sleep medications is an indicator of something else that links to an increased dementia risk,” said study lead author Yue Leng.
In other words, the investigation “cannot prove causation,” stressed Leng, an assistant professor in the Department of Psychiatry and Behavioral Sciences at the University of California, San Francisco.
Percy Griffin, director of scientific engagement with the Alzheimer's Association, seconded the thought.
“We do want to be careful,” said Griffin, who wasn't part of the study. He noted that observational studies of this kind can only identify an association between a “modifiable risk factor” -- like medication habits -- and dementia risk. “They don't prove cause and effect,” he said.
For the study, Leng and her team enlisted roughly 3,000 seniors to share their sleep medication routines starting in 1997.
Participants were between 70 and 79 years old, and none had dementia. All lived in Memphis or Pittsburgh. Nearly 6 in 10 were white and 4 in 10 were Black.
Three times over five years all were asked how often they took sleeping aids: never, rarely (once a month or less), sometimes (2 to 4 times a month), often (5 to 15 times a month), or almost always (16 to 30 times a month).
Participants also discussed the quality of their sleep, indicating how frequently they struggled with falling asleep and/or getting up too early in the morning. Routine sleep duration was also noted.
Sleep aids encompassed both over-the-counter and prescription medications. Common over-the-counter options included antihistamines, melatonin and valerian. Prescription meds included antidepressants, antipsychotics, benzodiazepines and so-called Z-drugs such as Ambien (zolpidem).
Overall, 7.7% of the white participants said they took some type of sleep medication often or almost always.
Yet 2.7% of Black participants reported a similar level of routine usage.
Among white and Black participants, frequent usage was highest among women, those struggling with depression and the more highly educated.
The team noted that benzodiazepine use for chronic insomnia -- including Halcion (triazolam), Dalmane (flurazepam) and Restoril (temazepam) -- was twice as high among white seniors compared with Black seniors. White participants were also seven times more likely to take a Z-drug like Ambien, and 10 times as likely to take the antidepressant trazodone (Desyrel and Oleptro).
After tracking participants for up to 15 years, the researchers found about one-fifth developed dementia.
While white seniors who used sleeping pills frequently faced a 79% higher risk for dementia, that was not the case among Black seniors -- and not just because far fewer Black adults took sleeping aids frequently. Those who did use them often appeared to face no higher risk for developing dementia than those who rarely or never took a sleeping med.
Leng said the racial gap her team identified was “surprising to us," particularly since prior research suggests that Black people generally face a higher risk for developing Alzheimer's than their white peers.
“One possible explanation could be that Black adults who have access to sleep meds are a selected group of people with high socio-economic status,” which might afford them a mental health leg up that's protective against dementia, Leng said.
Yet even among white seniors, Leng “wouldn't say sleep meds ‘boost' Alzheimer's disease risk” based on the findings. And her team stressed that “it remains controversial whether sleep medications are good or bad for cognition in the long run.”
It could turn out that certain meds might contribute to dementia risk, while others don't. Or that having sleep problems -- the reason for using sleep meds -- is a symptom of dementia onset, Leng suggested.
Both she and Griffin agreed additional research is needed.
“More work needs to be done,” said Griffin. “And we shouldn't be sounding the alarm bells just quite yet.”
Meanwhile, he offered some cautionary advice: “In general, before anyone takes any sleep medication, or any medication for that matter, they should have a conversation with their doctor to see how it might interact with any other medication they might already be taking." Their medical history and life story in general should also be considered, he added.
The study results appear online Jan. 31 in the Journal of Alzheimer's Disease.
There's more on the potential connection between sleep and Alzheimer's at Harvard Medical School.
SOURCES: Yue Leng, PhD, assistant professor, Department of Psychiatry and Behavioral Sciences, University of California, San Francisco; Percy Griffin, PhD, director of scientific engagement, Alzheimer's Association, Chicago; Journal of Alzheimer's Disease, Jan. 31, 2023