Several medication classes have been linked in research to a higher risk of cognitive decline or dementia when used long term, especially in older adults. None of them “cause” dementia on their own, and in many cases the absolute risk is small, but they’re important to review regularly with a clinician, particularly if you already have memory issues.
1. Strong anticholinergic drugs
Anticholinergics block acetylcholine, a brain chemical crucial for memory and attention; Alzheimer’s drugs actually work by boosting this same transmitter. Large studies and reviews show that higher cumulative exposure to strong anticholinergics (high ACB/“ACB3” score) is associated with increased dementia risk and faster cognitive decline.
Common strong anticholinergics include:
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Some bladder medications (e.g., oxybutynin, tolterodine).
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Older antihistamines for allergies or sleep (e.g., diphenhydramine, chlorphenamine).
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Certain tricyclic antidepressants (e.g., amitriptyline, imipramine).
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Some antiparkinson and antipsychotic drugs.
Geriatric Beers Criteria now advise avoiding strong anticholinergics in older adults, and especially in people with existing dementia, whenever safer alternatives exist.
2. Benzodiazepines and similar sedatives
Benzodiazepines (like diazepam, lorazepam, clonazepam) and related “Z‑drugs” (zolpidem, zopiclone) are widely used for anxiety and insomnia. They act on GABA receptors to dampen brain activity. Long‑term use has been associated with worse cognitive performance and, in some observational work, a higher incidence of dementia, although results are mixed and confounded by the fact that anxiety and insomnia themselves are dementia risk markers.
Because of falls, confusion, and potential cognitive effects, expert guidelines recommend short‑term use at the lowest effective dose, and gradual tapering in older adults when possible.
3. Certain anticonvulsants and mood stabilisers
Newer pharmaco‑epidemiology data suggest that chronic use of some anticonvulsants (for seizures, neuropathic pain, or mood disorders) may be linked with a higher incidence of dementia, though evidence is still evolving and varies by drug. Sedation, anticholinergic effects, and interactions with other CNS medicines may all contribute. Decisions about these drugs must balance seizure control and mood stability against long‑term risks.
4. Proton pump inhibitors (PPIs) – possible, but controversial
PPIs (omeprazole, esomeprazole, pantoprazole) reduce stomach acid and are widely used for reflux and ulcers. Some large cohort studies have reported modest associations between long‑term PPI use and dementia, particularly with higher cumulative exposure or in younger‑onset cases.
However, recent systematic reviews and meta‑analyses find inconsistent results and no clear causal link, concluding that any dementia risk from PPIs is unproven and, if present, likely small. Current advice is to:
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Avoid taking PPIs longer or at higher doses than needed.
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Regularly reassess the indication, especially in older adults.
5. Other CNS‑active drugs (polypharmacy)
Research looking at overall prescribing patterns finds that combinations of central nervous system (CNS) drugs and multiple anticholinergics together raise the risk of cognitive problems more than any single agent. Risk tends to rise with:
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Number of CNS‑active medicines (sedatives, opioids, antipsychotics, anticonvulsants).
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Total “anticholinergic burden” from all prescriptions and over‑the‑counter products.
The American Geriatrics Society recommends avoiding concurrent use of several CNS depressants and multiple anticholinergics in older adults when possible.
