Medications That Affect Memory

When memory starts slipping, medication is one of the first things worth checking and one of the last things people think of.

It is also one of the few causes you can often do something about within a few weeks.

Some of the medications involved are prescriptions. Several are sitting in ordinary bathroom cabinets, bought without a prescription, and taken for years by people who have no idea they affect thinking at all.

Can Medications Really Cause Memory Problems?

Yes. And the effect can be large enough to look like early dementia.

Older adults are more sensitive to these effects for reasons that have nothing to do with willpower. The liver and kidneys clear drugs more slowly with age. Body composition changes. And most people over 65 take several medications at once, so the effects stack.

The encouraging part is that this cause is often reversible. When the medication changes, thinking frequently improves.

Which Medications Affect Memory the Most?

The group with the strongest evidence behind it is a class called anticholinergics.

These drugs block a chemical messenger called acetylcholine. Your brain uses acetylcholine to form new memories, which is exactly why blocking it causes trouble.

A large English study followed nearly 59,000 people with dementia and compared them against more than 225,000 people without it. Researchers found meaningful links between dementia and several kinds of anticholinergic medication, including certain antidepressants, drugs for an overactive bladder, medications for Parkinson's disease, antipsychotics, and some antiseizure drugs.

This was an observational study. It shows a strong association rather than proof that the drugs caused the dementia. But the finding was consistent enough that the researchers urged caution in prescribing these medications to middle-aged and older adults.

What Are Anticholinergic Drugs?

This is where most people are surprised. Several of the strongest anticholinergics are sold over the counter.

• Diphenhydramine. The active ingredient in Benadryl, and in nearly every product with "PM" in the name. If you take a nighttime pain reliever to help you sleep, this is very likely what is doing the sleeping part.
• Older allergy medications. The drowsy kind. Newer allergy drugs are much less of a problem.
• Bladder medications. Drugs for overactive bladder are among the most strongly associated in the research.
• Older antidepressants. Particularly the tricyclic family, which is still prescribed for sleep and nerve pain at low doses.
• Some muscle relaxants, motion sickness drugs, and stomach antispasmodics.

A single dose is not the concern. The research points at regular use over months and years.

What About Sleeping Pills and Anxiety Medication?

Benzodiazepines are a second group worth reviewing. This family includes lorazepam, alprazolam, diazepam, and clonazepam, prescribed for anxiety and for sleep.

They interfere directly with forming new memories, which is part of how they work. In older adults they also cause drowsiness and unsteadiness, and unsteadiness leads to falls.

The American Geriatrics Society publishes a list of medications that are usually best avoided in people over 65. It is called the Beers Criteria, and both benzodiazepines and diphenhydramine are on it.

Your doctor and your pharmacist know this list. It is entirely reasonable to ask whether anything you take is on it.

Do Statins Cause Memory Loss?

This question comes up constantly, so it deserves a straight answer.

Some people do report fogginess on statins, and the U.S. Food and Drug Administration has noted it. But large reviews have not found that statins cause lasting memory problems, and the evidence is much weaker than for the drug groups above.

Meanwhile, high cholesterol is itself on the list of things linked to dementia risk, and statins protect against stroke and heart attack.

So this is a conversation to have with your doctor rather than a reason to quit. Stopping a statin because of something you read is a poor trade.

How Do You Get Your Medications Reviewed?

There is a simple version of this that works well.

Put every single thing you take into a bag. Prescriptions, over-the-counter medicines, vitamins, supplements, herbal products, eye drops, anything. Then take the bag to your doctor or your pharmacist and ask for a review.

Pharmacists are excellent at this and are often easier to get an appointment with. Many will do it at no charge.

A few things worth saying out loud during that visit:

• "I have noticed changes in my memory. Could any of these be contributing?"
• "Is anything here on the Beers list?"
• "Is there a version of this that is gentler on thinking?"
• "Do I still need all of these?"

That last question is often the most valuable one. Medications get started for good reasons and then continue for years because nobody revisits them.

How Do You Know If It Helped?

This is the part people skip, and it is the part that tells you whether the change worked.

If you take a memory screening before a medication change and again a few months after, you have something to compare. Without a starting point, you are left guessing whether you feel sharper or simply hoped you would.

Memory Exam is a 10 to 15 minute verbal assessment you can take at home. It shows whether your memory performance differs from what is expected for someone your age and background, and taken again later, it compares you against your own earlier result.

Memory Exam is a screening tool, not a diagnosis. Results should be discussed with a qualified doctor or healthcare professional when appropriate.

One Appointment Is Often Enough

Of everything known to affect memory, this is among the most fixable.

You do not need to change your diet, join a gym, or rearrange your life. You need a bag, an appointment, and a willingness to ask whether you still need all of it.

If something on this page sounded familiar, that is worth following up on. Other reversible causes of memory loss are worth checking at the same visit.

Where This Information Comes From

• Coupland CAC, Hill T, Dening T, et al. Anticholinergic drug exposure and the risk of dementia: a nested case-control study. JAMA Internal Medicine 2019;179(8):1084-1093.
• American Geriatrics Society 2023 Updated AGS Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. Journal of the American Geriatrics Society 2023.
• World Health Organization. Risk reduction of cognitive decline and dementia: WHO guidelines, second edition. July 2026.