Some medicines older adults take, such as certain allergy and sleep products, bladder medicines and anxiety or sleeping pills, are linked in studies to confusion, falls and a higher chance of a later dementia diagnosis. The studies show an association, not proof that the medicine caused dementia, and the evidence differs by drug. This page is general information: the prescriber decides what a person takes, and nobody should stop a prescribed medicine suddenly.
Does Benadryl cause dementia?
Benadryl is a brand name for diphenhydramine, an older (first-generation) antihistamine. No source we checked says it has been proven to cause dementia. What exists is research on “anticholinergic” drugs as a group, which block a brain chemical involved in memory and attention, plus a strong professional caution about using diphenhydramine in older age.
The American Geriatrics Society (AGS) lists oral diphenhydramine among the first-generation antihistamines to avoid in older adults. In its 2023 Beers Criteria the rationale reads that these drugs are highly anticholinergic and risk confusion, dry mouth and constipation, and that cumulative exposure to anticholinergic drugs is associated with a higher risk of falls, delirium and dementia. The same entry says diphenhydramine may be appropriate in situations such as treating a severe allergic reaction.
MedlinePlus says the same in plain terms: generally it should not be used in older adults except to manage serious allergic reactions. It is also an ingredient in many products labeled “PM” or “nighttime,” so someone can take it without realizing. Check the active ingredients on the label or ask the pharmacist.
Which medicines do doctors ask older adults to review?
The AGS Beers Criteria is a list of medicines whose risks may outweigh their benefits for adults 65 and older. According to the AGS Health in Aging Foundation, it is a resource for health professionals, not a replacement for their judgment, and for some people a listed medicine is still the best choice. The groups below are the ones most often asked about in connection with memory.
| Medicine group | Examples named in Beers | What the 2023 Beers Criteria say |
|---|---|---|
| First-generation antihistamines | Diphenhydramine, doxylamine, hydroxyzine, meclizine, chlorpheniramine | Avoid. Highly anticholinergic; may be appropriate for severe allergic reactions |
| Bladder antimuscarinics (for urinary incontinence) | Oxybutynin, tolterodine, solifenacin, darifenacin, fesoterodine, trospium | Listed as strongly anticholinergic. The panel says oxybutynin has the best evidence for adverse cognitive effects and urges caution with all of them |
| Some antidepressants | Amitriptyline, imipramine, nortriptyline, paroxetine | Listed as strongly anticholinergic |
| Benzodiazepines (anxiety, sleep, seizures) | Alprazolam, lorazepam, clonazepam, diazepam, temazepam | Avoid. Increase the risk of cognitive impairment, delirium, falls and fractures; may be appropriate for some conditions such as seizure disorders |
| “Z-drugs” (sleep) | Zolpidem, eszopiclone, zaleplon | Avoid. Adverse events similar to benzodiazepines, with minimal improvement in sleep |
For people who already have dementia or cognitive impairment, Beers also advises avoiding anticholinergics, benzodiazepines and Z-drugs because of their effects on the central nervous system. It separately advises avoiding more than one anticholinergic drug at a time and avoiding three or more brain-active drugs together. Whether any of this applies to a particular person is for the prescriber to say. Some of these drugs are prescribed for good reasons that only the doctor can weigh.
What does the research show, and what does it not show?
Large studies have found an association between long-term use of these drug groups and a later dementia diagnosis. None of them can show the drug is the cause.
| Study | What it found | Limits the authors noted |
|---|---|---|
| Seattle cohort, JAMA Internal Medicine, 2015 (3,434 people 65+) | Dementia risk rose with cumulative anticholinergic use; the highest group had a hazard ratio of 1.54 compared with non-users | Observational; the most recent year of use was excluded to avoid drugs given for early symptoms |
| English case-control study, JAMA Internal Medicine, 2019 (284,343 people) | Odds of dementia were 1.49 times higher for the highest cumulative use of strong anticholinergics; significant increases for several classes, including bladder drugs and some antidepressants | Observational; the abstract’s list of classes with significant increases does not include antihistamines |
| Quebec case-control, BMJ, 2014 (benzodiazepines) | Higher odds of Alzheimer’s disease (1.51 for ever use); no association below 91 daily doses; stronger with longer exposure | Authors say use may also be an early marker of a condition linked to dementia |
| Seattle cohort, BMJ, 2016 (benzodiazepines) | Slightly higher dementia risk at low exposure, not at the highest; no faster cognitive decline | Authors write that results do not support a causal association |
| Meta-analysis, J Prev Alzheimer’s Dis, 2024 (26 studies of sleep medicines) | Relative risk 1.23 for hypnotics overall; in one cohort, significant for benzodiazepines and Z-drugs but not melatonin | Authors cite heterogeneity; neither association was significant in people with a history of insomnia |
Two things make the picture hard to read. The reason someone takes the drug (poor sleep, anxiety, bladder trouble, depression) can itself be an early sign of brain changes, so the medicine may be a marker rather than a cause. And studies of this kind cannot rule out other differences between users and non-users. That is why the authors of the 2016 benzodiazepine paper and a 2026 melatonin study both warn against reading their results as proof of cause.
What is better established in the Beers Criteria is nearer-term harm: confusion, delirium, falls and fractures. Our guide to delirium versus dementia explains why a sudden change in thinking needs prompt medical attention.
Does melatonin cause dementia?
The sources we checked do not show that melatonin causes dementia. They do show that the evidence on older adults is thin. The National Center for Complementary and Integrative Health says short-term use appears safe for most people but information on long-term safety is lacking. It adds that melatonin may stay active longer in older people and cause daytime drowsiness, and that 2015 American Academy of Sleep Medicine guidelines recommend against its use by people with dementia.
A 2026 study in Scientific Reports found people newly prescribed melatonin had higher observed dementia rates than those prescribed benzodiazepines or zolpidem. Its authors say this should not be read as a causal effect and may reflect confounding and early disease. In the 2024 analysis above, the link was not significant for melatonin. The honest answer is “unclear,” and a question for the prescriber.
Does Ambien cause dementia?
Ambien is a brand name for zolpidem, a Z-drug. Research links hypnotics as a group to higher dementia risk, as in the table above, but no study we read shows zolpidem on its own causes it. The more concrete concerns are in the Beers Criteria and FDA warnings.
- Beers: Z-drugs have adverse events similar to benzodiazepines in older adults, including delirium, falls, fractures and emergency visits, with minimal improvement in time to fall asleep or sleep duration.
- FDA, April 2019: a boxed warning for eszopiclone, zaleplon and zolpidem about complex sleep behaviors such as sleepwalking and sleep driving, which have caused serious injuries and deaths.
- MedlinePlus: zolpidem can cause memory problems and confusion, family should know these symptoms matter, and older adults should not usually take it.
NIA’s research highlight on deprescribing also calls zolpidem potentially inappropriate for older adults.
Why should nobody stop these medicines suddenly?
Because stopping can cause its own harm. The FDA warns that physical dependence on benzodiazepines can occur when they are taken steadily for several days to weeks, even as prescribed. Stopping abruptly or lowering the dose too quickly can cause withdrawal reactions, including seizures that can be life-threatening, and some people have had symptoms for many months. The FDA says a gradual taper should follow a patient-specific plan from the prescriber.
MedlinePlus says not to stop zolpidem without talking to the doctor, especially after more than two weeks, and lists shakiness, cramps, nausea, sweating and mood changes as possible withdrawal symptoms. The AGS Health in Aging Foundation and NIA give the same advice for all medicines: do not stop without checking with the provider. The Beers panel adds that deprescribing involves more than telling someone to stop, including tapering and withdrawal symptoms.
Never stop, start, skip or change any of these medicines, including over-the-counter ones, because of something you read online, including this page.
How do you ask for a medication review?
The AGS suggests that if a medicine you take is listed in Beers, you ask your health professional whether there is a safer or more effective choice, and it may still be reasonable for you. A practical way to do that:
- Make one complete list (see the next section) and bring it to every appointment.
- Ask for a medication review. Tell the doctor or nurse practitioner you want all medicines, including over-the-counter, checked together, and ask which are still needed.
- Bring the bottles. AHRQ describes a “brown bag” review: patients bring all their medicines in their containers, along with pill boxes, so the clinician can see what is actually taken and how. AHRQ says every patient should have one at least once a year.
- Ask the pharmacist. Pharmacists can answer questions about prescriptions, over-the-counter products and supplements, and NIA suggests using one pharmacy where possible so interactions are caught.
- Ask the exit question. NIA’s questions for a doctor include whether it is safe to stop a medicine abruptly and what to do about side effects.
- Ask your Part D plan about Medication Therapy Management. Medicare.gov says plans must offer it to people who qualify, at no cost, usually a discussion with a pharmacist or provider and a written summary. In New York, free Medicare counseling is available through HIICAP at 1-800-701-0501.
How do you keep an accurate medication list?
NIA’s guidance for people with Alzheimer’s and their caregivers is to know every prescription medicine, over-the-counter drug, vitamin, supplement and herbal remedy the person takes, and to keep a written list. Update it whenever anything changes.
| What to write down | Why it helps |
|---|---|
| Name, amount and time of day, for every item | Lets the pharmacist and doctor spot duplicates and interactions |
| Who prescribed it and why | Shows which medicines nobody is reviewing |
| Over-the-counter and “PM” products, vitamins, herbal remedies | The easiest items to leave off; NIA says to mention everything, even ones used rarely |
| Allergies and past reactions | Helps avoid repeating a problem |
| Changes you noticed (sleepiness, confusion, falls) and the date | Gives the prescriber specifics to work with |
Keep one copy at home and one in a wallet or purse, as NIA advises. Our guide to medication management for seniors covers organizers and routines.
What can home care do about medicines and memory?
Home care does not choose, change or stop medicines. That belongs to the prescriber. What a caregiver can do is notice and report.
- Reminders. Our home health aides give medication reminders; administering injections and similar nursing tasks is done by nurses, which is what our nurse services cover.
- Noticing changes. New drowsiness, confusion, restlessness, a fall, constipation, trouble passing urine or odd nighttime behavior after a medicine change are worth writing down. The Beers entries and FDA warnings above are why.
- Reporting. Aides report changes to the family and the supervising nurse, who can pass them on to the prescriber. A new problem after a new medicine is a reason to call the prescriber or pharmacist promptly. Trouble breathing or a seizure is an emergency: call 911.
- Appointments. A medical escort can help the person get through the visit and write down what the doctor says.
See also our guides to dementia care at home and fall prevention in New York apartments.
We are a licensed home care agency in Brooklyn and Queens, licence #2572L001, New York State Department of Health. We cannot advise on medicines, but we can talk through what daily help is available. Call (718) 232-2777 or use our contact page.
Research and drug warnings change. Everything above was checked on 12 October 2026 against pmc.ncbi.nlm.nih.gov and pubmed.ncbi.nlm.nih.gov (AGS Beers Criteria and study abstracts), healthinaging.org, nia.nih.gov, nccih.nih.gov, fda.gov, medlineplus.gov, ahrq.gov, medicare.gov and shiphelp.org. This page is general information, not medical advice. Ask the prescriber or a pharmacist about any specific medicine.
Frequently asked questions
Does Benadryl cause dementia?
It has not been proven to. Studies link long-term, high cumulative use of anticholinergic drugs, a group that includes diphenhydramine, to higher dementia rates, but they cannot prove cause. The AGS advises older adults to avoid oral diphenhydramine, mainly because of confusion and falls. Ask the prescriber or pharmacist about your own situation.
Does melatonin cause dementia?
The sources we reviewed do not show that. NCCIH says long-term safety information is lacking and that 2015 sleep medicine guidelines recommend against melatonin in people with dementia. One 2026 study found higher observed dementia rates in melatonin users, and its authors say that should not be read as cause.
Does Ambien cause dementia?
No study we read proves that. Hypnotics as a group are linked to higher dementia risk in observational studies. The Beers Criteria advise avoiding zolpidem in older adults because of delirium, falls and fractures, and the FDA has a boxed warning about complex sleep behaviors.
Is it safe to stop a sleeping pill or anxiety medicine on my own?
No. The FDA warns that stopping benzodiazepines abruptly can cause withdrawal reactions, including life-threatening seizures, and MedlinePlus gives similar advice for zolpidem. The prescriber can plan a gradual change if one is appropriate.
What is the Beers Criteria?
It is a list from the American Geriatrics Society of medicines that may carry more risk than benefit for people 65 and older, last updated in 2023. It is a tool for clinicians, not an order to stop anything. Some people still need a listed medicine.
What is a brown bag medication review?
You bring every medicine in its container, plus vitamins, supplements, over-the-counter products and pill boxes, to an appointment so a doctor, nurse or pharmacist can check them together. AHRQ recommends one at least once a year.
Can a home health aide manage my parent’s medicines?
An aide can give reminders and can observe and report changes to the family and the supervising nurse. Choosing, changing or stopping a medicine is the prescriber’s decision, and nursing tasks such as injections are done by nurses.
