7 Medications That Can Affect Memory and Cognitive Function
The claim that certain medications “cause severe dementia and profound brain damage” is too strong. Some medicines can cause confusion, delirium, sedation, or cognitive impairment—especially in older adults—and long-term exposure to certain drug classes has been associated with increased dementia risk. That does not mean every person taking these medicines will develop dementia or permanent brain damage. PubMed Central (PMC)
1. Diphenhydramine
Diphenhydramine is a first-generation antihistamine found in some allergy and sleep products. Its strong anticholinergic effects can cause confusion and other cognitive problems, particularly in older adults.
The 2023 American Geriatrics Society Beers Criteria recommends avoiding first-generation antihistamines such as diphenhydramine in older adults when possible. PubMed Central (PMC)
2. Amitriptyline
Amitriptyline is a tricyclic antidepressant that has strong anticholinergic effects.
In older adults, these effects can contribute to confusion, sedation, dizziness, and cognitive problems. It is therefore included among medications that the Beers Criteria recommends avoiding in many older adults. PubMed Central (PMC)
3. Oxybutynin
Oxybutynin is used to treat overactive bladder. It has significant anticholinergic activity.
Among bladder antimuscarinic medicines, oxybutynin has some of the strongest evidence for adverse cognitive effects, so clinicians should consider cognitive risks when prescribing it, particularly to older adults. PubMed Central (PMC)
4. Benzodiazepines
Examples include diazepam, lorazepam, alprazolam, clonazepam, and temazepam.
These medications can cause sedation, impaired memory, confusion, falls, and delirium. Older adults are particularly sensitive to their effects.
They can be appropriate for specific medical conditions, so they should not be stopped suddenly after regular use because withdrawal can be dangerous. PubMed Central (PMC)
5. Z-Drugs
Sleep medicines such as zolpidem, eszopiclone, and zaleplon act on similar brain pathways to benzodiazepines.
In older adults, they can increase risks of cognitive impairment, delirium, falls, and fractures. The Beers Criteria recommends avoiding them when possible. PubMed Central (PMC)
6. Strong Anticholinergic Medications
This isn’t one particular drug but a group of medications. Examples include certain antihistamines, antidepressants, bladder medicines, antispasmodics, and other drugs.
Importantly, the risk can increase when a person takes several anticholinergic medicines at the same time. The Beers Criteria specifically recommends minimizing cumulative anticholinergic exposure in older adults. PubMed Central (PMC)
7. Antipsychotic Medications
Antipsychotics can be essential treatments for conditions such as schizophrenia, bipolar disorder, and certain other psychiatric illnesses.
However, in older adults with dementia, these medicines are associated with increased risks of stroke, cognitive decline, and mortality. They therefore shouldn’t be used routinely for behavioral symptoms of dementia unless specific circumstances justify their use. PubMed Central (PMC)
Don’t Stop These Medicines on Your Own
A medication appearing on this list doesn’t mean you should stop taking it. Abruptly stopping certain drugs, particularly benzodiazepines, can cause serious withdrawal effects.
Instead, ask your doctor or pharmacist to review your complete medication list—including prescription drugs, over-the-counter sleep aids, allergy medicines, and supplements.
Bottom Line
Some medications can contribute to confusion, delirium, memory problems, or cognitive decline, particularly in older adults. The greatest concern is often the cumulative effect of multiple medications, rather than one medicine automatically causing “brain damage.” PubMed Central (PMC)
If you notice new confusion, memory problems, excessive sleepiness, or personality changes after starting or increasing a medication, have the medication regimen reviewed by a healthcare professional.
