Some commonly used medicines have been linked with cognitive decline or dementia, particularly when used for long periods. Learn which medication groups deserve extra caution and why you should never stop a prescribed medicine without medical advice.
A headline such as “8 drugs that cause severe dementia” is too strong. Current evidence does not establish that these medicines directly cause dementia. The strongest concern is with certain medications—especially those with anticholinergic effects—and the risk appears to depend on factors such as dose, duration, age, and a person’s overall health.
1. Strong Anticholinergic Medicines
This is the medication group with some of the clearest evidence of an association with dementia risk. Anticholinergic drugs can interfere with acetylcholine, a chemical messenger important for memory and thinking. Long-term use has been associated with higher dementia incidence in several observational studies.
Examples can include certain medicines used for:
- Overactive bladder
- Allergies
- Sleep problems
- Depression
- Some gastrointestinal conditions
2. Bladder Antimuscarinics
Some medicines prescribed for urinary urgency and overactive bladder have anticholinergic properties. Studies have reported an association between prolonged exposure and dementia, although this does not prove that the medicine itself is the cause.
3. Benzodiazepines
Medicines in this group are commonly prescribed for anxiety, insomnia, and certain seizure disorders. Some observational studies have found an association between benzodiazepine use and dementia. However, reviews emphasize that the evidence is uncertain and cannot establish a direct cause-and-effect relationship.
4. Certain Sleep Medicines
Some sedative-hypnotic medicines, particularly Z-drugs, have also been associated with dementia in observational research. The evidence is not strong enough to say that these medications directly cause dementia.
5. Some Older Antihistamines
Certain older antihistamines have significant anticholinergic effects. Repeated or long-term exposure can contribute to the overall anticholinergic burden, which is an important consideration in older adults.
6. Some Antidepressants With Anticholinergic Effects
Not every antidepressant carries the same concern. The issue is particularly relevant to medicines with stronger anticholinergic activity. Doctors may consider alternatives when treating older adults who already have memory or cognitive problems.
7. Some Medicines for Parkinson’s Disease
Certain older Parkinson’s medicines can have anticholinergic effects. Their benefits and risks need to be weighed individually, especially in older people who are experiencing memory problems.
8. Multiple Medicines Used Together
Sometimes the bigger issue isn’t one particular drug—it’s the combined anticholinergic burden from several medicines. Taking multiple medications with anticholinergic properties can increase the overall exposure.
Don’t Stop Your Medication Suddenly
This is extremely important: never stop a prescription medicine because of a social-media article or this list. Some medications, particularly benzodiazepines and certain psychiatric or neurological medicines, can cause serious withdrawal problems if stopped suddenly.
Instead, ask your doctor or pharmacist:
“Could any of my medicines affect my memory or cognition? Is there a safer alternative?”
A 2025 umbrella review found moderate-certainty evidence of increased dementia risk associated with anticholinergic medicines, while also emphasizing that much of the medication-dementia evidence comes from observational research and therefore cannot always prove causation.
Bottom line: The goal isn’t to make people afraid of necessary medicines. It’s to encourage older adults—and their families—to periodically review all medications with a healthcare professional, particularly when memory problems, confusion, or excessive drowsiness appear.