Certain medications have been linked in research to a higher risk of dementia or cognitive decline, particularly when they are used for long periods or when several medications with similar effects are taken together.
But there’s an important distinction: an association does not prove that a medication causes dementia. Older adults who need certain medicines may already have health conditions that independently increase dementia risk. Researchers call this problem confounding and reverse causation, and it makes some medication studies difficult to interpret.
The strongest concern currently centers on medications with anticholinergic effects, while evidence for several other drug groups remains mixed.
1. Strong Anticholinergic Medications
This is the group that deserves the most attention.
Anticholinergic medicines block the action of acetylcholine, a chemical messenger involved in memory, attention, learning, and other functions.
They are used for many different conditions, including allergies, overactive bladder, depression, dizziness, Parkinson’s disease, and some gastrointestinal problems.
Examples of medicines with anticholinergic properties include:
- Some older antihistamines
- Certain bladder medications
- Some tricyclic antidepressants
- Certain medicines for Parkinson’s disease
- Some drugs used for nausea or motion sickness
Long-term exposure has been associated with cognitive impairment and dementia in multiple observational studies. A meta-analysis of 26 studies involving more than 621,000 participants found an association between anticholinergic use and dementia, although the evidence varied considerably between studies.
Another systematic review and meta-analysis found an association between anticholinergic medications and dementia, including evidence of a dose-response relationship.
A large prospective cohort study of adults aged 70 and older also found that people with a higher anticholinergic burden had a higher incidence of dementia, although the researchers noted that residual confounding and reverse causality could not be completely excluded.
Why this matters
You don’t necessarily need to stop an anticholinergic medication. The important question is whether you still need it and whether an alternative with less anticholinergic activity might be appropriate.
NICE specifically recommends considering ways to minimize medicines that contribute to anticholinergic burden during medication reviews.
2. Benzodiazepines and Certain Sedatives
Benzodiazepines include medicines such as:
- Diazepam
- Lorazepam
- Alprazolam
- Clonazepam
They’re commonly prescribed for anxiety, panic disorders, seizures, muscle spasms, and sometimes insomnia.
Several observational studies have found an association between benzodiazepine use and dementia. One meta-analysis found higher dementia odds among users, while another review found associations ranging from roughly 1.38 to 1.78 times the odds of dementia.
However, this evidence doesn’t establish that benzodiazepines cause dementia. Anxiety, insomnia, depression, and other symptoms that lead to benzodiazepine treatment can themselves occur during the early stages of cognitive disease, potentially making the association look stronger than it really is.
Don’t stop suddenly
If you’ve been taking a benzodiazepine regularly, don’t abruptly discontinue it. Withdrawal can be serious, and the dose may need to be reduced gradually under medical supervision.
3. Proton Pump Inhibitors: A Controversial Group
Proton pump inhibitors (PPIs) are widely used to treat acid reflux, ulcers, and other gastrointestinal conditions.
Examples include:
- Omeprazole
- Esomeprazole
- Lansoprazole
- Pantoprazole
PPIs have received considerable attention because some observational studies have reported an association with dementia.
But the evidence is inconsistent.
A 2023 systematic review and meta-analysis found no clear evidence that PPI use increases dementia risk. A 2020 meta-analysis of prospective studies likewise found no significant relationship.
More recent reviews continue to find substantial inconsistency. A 2026 umbrella review concluded that most systematic reviews did not support a link and that a causal relationship appeared unlikely based on the available evidence.
So PPIs should not be presented as proven dementia-causing drugs.
If you’re taking one unnecessarily for years, however, it’s reasonable to ask your healthcare professional whether you still need it.
4. Some Antidepressants With Anticholinergic Effects
This category requires some nuance.
Certain older antidepressants, particularly tricyclic antidepressants, can have substantial anticholinergic activity.
Examples include:
- Amitriptyline
- Imipramine
- Nortriptyline
- Clomipramine
The concern isn’t necessarily that antidepressants as a whole cause dementia. Rather, some individual medications contribute significantly to anticholinergic burden.
Research has found associations between anticholinergic antidepressants and cognitive outcomes, but depression itself is also associated with later cognitive decline, making cause and effect difficult to establish.
If an older adult is taking a medication such as amitriptyline for chronic pain or sleep, it can be worthwhile to ask whether another option might provide similar benefits with fewer anticholinergic effects.
5. Certain Bladder Medications
Some medications used to treat overactive bladder and urinary incontinence work by blocking muscarinic receptors and therefore have anticholinergic effects.
Examples include some bladder antimuscarinics such as:
- Oxybutynin
- Tolterodine
- Solifenacin
Research has raised concerns about long-term exposure. A meta-analysis found increased dementia risk associated with anticholinergic treatment lasting at least three months, including bladder antimuscarinic medications.
This doesn’t mean someone should simply stop bladder medication. Urinary symptoms can significantly affect sleep, independence, and quality of life.
Instead, ask whether your particular medicine is contributing to your overall anticholinergic burden and whether alternatives exist.
6. Some Antihistamines
Older first-generation antihistamines can have significant anticholinergic effects.
Examples include medications containing:
- Diphenhydramine
- Chlorpheniramine
- Hydroxyzine
They can cause drowsiness, confusion, dry mouth, constipation, and urinary retention—effects that may be particularly troublesome in older adults.
Some people use these medications regularly as sleep aids, which is worth discussing with a healthcare professional.
Importantly, not all antihistamines have the same anticholinergic profile. Newer antihistamines generally have less penetration into the brain and tend to be less sedating.
7. Multiple Medications Taken Together
Sometimes the issue isn’t one particular drug.
An older adult might simultaneously take:
- A sleep medication
- An antihistamine
- A bladder medication
- An antidepressant
- A pain medication
Individually, each may seem reasonable. Together, however, their effects on cognition, alertness, balance, and the nervous system can add up.
This is known as medication burden or, in the case of anticholinergic drugs, anticholinergic burden.
Studies have found higher dementia rates among people exposed to multiple anticholinergic medications, although observational research cannot prove that the medications themselves caused the dementia.
What About Blood Pressure and Cholesterol Medicines?
It’s important not to lump all commonly used medications into a “dementia-causing” category.
For example, claims that statins or blood-pressure medications generally cause dementia are not supported by good evidence.
In fact, controlling cardiovascular risk factors such as high blood pressure is important because vascular disease itself can contribute to cognitive impairment and dementia.
Never stop a cardiovascular medication because of a social-media post or alarming headline.
Why Is It So Difficult to Prove That a Drug Causes Dementia?
Dementia usually develops over many years.
Imagine a person begins having sleep problems, anxiety, urinary symptoms, or depression years before receiving a dementia diagnosis. Those symptoms may lead to medication use.
Later, the person develops dementia.
Did the medication cause the dementia?
Or did the early symptoms of an evolving disease lead to the medication being prescribed?
This is one reason observational studies can produce associations without proving causation.
Randomized long-term trials would provide stronger evidence, but conducting them for dementia outcomes over decades is extremely difficult.
Signs That Your Medication May Be Affecting Your Thinking
Medication-related cognitive effects can sometimes appear as:
- New confusion
- Excessive sleepiness
- Difficulty concentrating
- Memory problems
- Dizziness
- Problems with balance
- Increased falls
- Delirium
- Unusual changes in behavior
These symptoms don’t automatically mean dementia.
Medication side effects, infections, dehydration, sleep disorders, depression, metabolic problems, and many other conditions can produce similar symptoms.
Sudden confusion in an older adult should be evaluated promptly because delirium can be caused by an acute medical problem.
What Should You Do If You’re Worried?
Don’t throw away your medications or stop them suddenly.
Instead, request a medication review with your doctor or pharmacist.
Ask:
- Do I still need every medication I’m taking?
- Which medicines have anticholinergic effects?
- Is my total anticholinergic burden high?
- Could any medication be contributing to memory problems or confusion?
- Is there a safer alternative?
- Can any medication be reduced or discontinued safely?
- Could any of my symptoms actually be caused by another medical condition?
Bring a complete list of everything you take, including over-the-counter medicines, sleep aids, vitamins, and herbal products.
The Bottom Line
The strongest medication-related concern regarding long-term cognitive health involves anticholinergic burden, particularly when several medications with anticholinergic properties are used over time.
Benzodiazepines have also been associated with dementia in observational research, although causation remains uncertain.
For PPIs and several other commonly discussed medications, the evidence is much less convincing and remains inconsistent.
The takeaway isn’t “medications cause dementia.” It’s:
The more medications you take—especially those with anticholinergic or sedating effects—the more important a regular medication review becomes.
For older adults, periodically checking whether every medication is still necessary can reduce unnecessary side effects and potentially lower medication-related cognitive risks—without sacrificing treatments that are genuinely beneficial.