Benzodiazepines Don’t Increase Dementia Risks in Older Adults, USC Study Finds

There is little evidence that older adults prescribed benzodiazepines—drugs commonly used to treat anxiety, insomnia and seizures—are at increased risk of developing dementia, according to new research from the USC Schaeffer Center published in Alzheimer’s & Dementia.

The findings contribute to efforts made by researchers to better understand whether there are links between medications commonly prescribed to treat chronic conditions and dementia risk.

“While these drugs should be carefully prescribed given their risky side effects for older adults, our research diverges from previous studies to find that benzodiazepines do not increase dementia risk,” said study coauthor Geoffrey Joyce, a senior fellow at the USC Schaeffer Center and an associate professor at the USC School of Pharmacy.

Identifying a link between dementia and medications that treat chronic conditions

Use of widely prescribed medications for chronic conditions has been hypothesized to influence risk of Alzheimer’s disease as well as other dementias. Blood pressure medications like statins and antihypertensives have been associated with lowering dementia risk while medications with anticholinergic properties that treat allergies, incontinence and depression pose an increased dementia risk.

Benzodiazepines have also been linked to increased dementia risk, but it is unclear whether this class of drugs increases risk or are prescribed for conditions that are also early symptoms of dementia.

“Understanding of the pathology of Alzheimer’s disease has significantly increased, however there remains gaps in the evidence regarding how drugs used to treat chronic conditions affect Alzheimer’s risk,” said study coauthor Julie Zissimopoulos, co-director of Aging and Cognition Research Program at the USC Schaeffer Center and associate professor at the USC Sol Price School of Public Policy. “Given how common benzodiazepine use is, we thought it was important to understand whether or not the data show evidence of a causal link.”

The researchers used Medicare claims between 2006 and 2020 to study benzodiazepine use and dementia diagnosis for patients 67 years of age and older. The study was designed to examine prior case-control studies to evaluate factors, including a patient’s co-occurring health conditions and the length of time a patient is observed in the study, that might have led to an association between benzodiazepines and dementia. Additionally, they identified a group of patients without health conditions associated with dementia who were either prescribed, or not prescribed, benzodiazepines for pain diagnoses including cervical and lumbar pain, stenosis, and sciatica.

“According to our data, patients with benzodiazepine prescriptions generally have markedly higher rates of depression, anxiety and insomnia as well as a history of hypertension, hyperlipidemia, diabetes and stroke—all conditions that once accounted for reduced the association between benzo use and dementia risk,” explained Zissimopoulos. “When we compared patients prescribed benzos solely for pain compared to patients not prescribed benzos for pain, we find little difference in risk of dementia onset.”

Providers should still limit extended benzodiazepine use among older adults

Despite finding no increase in dementia risk, decades of research show increased risk of injury from disorientation, balance problems and daytime drowsiness when taking benzodiazepines.

The U.S. Food and Drug Administration also recently updated the boxed warning on all benzodiazepines to underscore the risks of abuse, addiction, physical dependence, and withdrawal reactions.

“Understanding the mechanisms- and possible interactions- between commonly prescribed drugs and Alzheimer’s risk is increasingly important given the large share of older Americans who are taking many prescriptions to manage multiple chronic conditions,” said Joyce.

Patricia Ferido, Johanna Thunnel and Bryan Tysinger of the USC Schaeffer Center also contributed to this study. An issue brief about the body of work on Alzheimer’s disease risk and use of prescription medications for chronic conditions can be found here.