7 Medications That Can Affect Memory and Cognitive Function
The claim that medications “cause severe dementia and profound brain damage” is misleading. Some medicines can cause confusion, delirium, sedation, or memory problems—particularly in older adults—and long-term exposure to some drug classes has been associated with increased dementia risk. That does not mean that everyone taking them will develop dementia or permanent brain damage. PubMed Central (PMC)
1. Diphenhydramine
Diphenhydramine is a first-generation antihistamine found in some allergy and sleep medicines. It has strong anticholinergic effects, which can cause confusion, drowsiness, and other cognitive problems, especially in older adults.
It is listed in the American Geriatrics Society Beers Criteria as a medication generally best avoided by older adults when possible. PubMed Central (PMC)
2. Amitriptyline
Amitriptyline is a tricyclic antidepressant with strong anticholinergic properties.
In older adults, it can contribute to confusion, sedation, dizziness, and cognitive difficulties. The Beers Criteria recommends avoiding amitriptyline and several similar antidepressants in many older adults. PubMed Central (PMC)
3. Oxybutynin
Oxybutynin is commonly prescribed for overactive bladder.
Because it has significant anticholinergic activity, it can affect cognitive function. Among bladder antimuscarinic drugs, oxybutynin has particularly strong evidence for adverse cognitive effects, although caution may be appropriate with other drugs in the same class as well. PubMed Central (PMC)
4. Benzodiazepines
Examples include diazepam, lorazepam, alprazolam, clonazepam, and temazepam.
These medicines can cause sedation, impaired memory, confusion, delirium, and falls. Older adults are particularly sensitive to these effects. PubMed Central (PMC)
They can nevertheless be appropriate for certain medical conditions. They should not be stopped suddenly after regular use because withdrawal can be dangerous.
5. Z-Drugs
Sleep medications such as zolpidem, zaleplon, and eszopiclone are sometimes called Z-drugs.
In older adults, they can increase the risk of cognitive impairment, delirium, falls, and fractures. The Beers Criteria recommends avoiding them when possible. PubMed Central (PMC)
6. Antipsychotic Medications
Antipsychotics include medicines such as quetiapine, risperidone, olanzapine, and haloperidol.
These medications can be essential for certain psychiatric and neurological conditions. However, in people with dementia, antipsychotics are associated with an increased risk of stroke, cognitive decline, and mortality. They therefore should not routinely be used simply to manage behavioral symptoms of dementia. PubMed Central (PMC)
7. Other Strong Anticholinergic Medicines
Anticholinergic effects aren’t limited to one medication. Other examples include certain antihistamines, antidepressants, bladder medications, anti-nausea medicines, and muscle relaxants.
The concern can become greater when someone takes multiple anticholinergic medications simultaneously, because cumulative exposure is associated with increased risks of cognitive decline, delirium, and falls. PubMed Central (PMC)
Don’t Stop Medication Without Medical Advice
A medication on this list isn’t necessarily inappropriate for you. Doctors prescribe these medicines for legitimate conditions, and the benefits may outweigh the risks for an individual patient.
If you or an older family member is experiencing new confusion, memory problems, excessive sleepiness, dizziness, or changes in behavior, ask a doctor or pharmacist to review all prescription medicines, over-the-counter products, and supplements.
Bottom Line
Some medications—particularly strong anticholinergics, benzodiazepines, Z-drugs, and certain antipsychotics—can negatively affect cognition, especially in older adults. But saying they automatically cause “severe dementia and profound brain damage” overstates the evidence. PubMed Central (PMC)
A medication review can help identify whether a particular drug, dose, combination, or underlying medical condition may be contributing to cognitive symptoms.
