7 Types of Medications That May Affect Memory and Thinking

You may have seen headlines claiming that certain medicines “cause severe dementia and profound brain damage.” That wording is too strong and can be misleading.

Some medications—particularly when used by older adults, at higher doses, for long periods, or in combination with other medicines—can cause confusion, drowsiness, delirium, or problems with memory and thinking. Some medication classes have also been associated with an increased risk of cognitive decline or dementia, although an association does not prove that a medication directly causes dementia in every person. (PubMed Central (PMC))

Here are seven important medication groups to discuss with a healthcare professional if you’re concerned about cognition.

1. Benzodiazepines

Examples include diazepam, lorazepam, alprazolam, clonazepam, and temazepam.

These medications are used for conditions such as anxiety, seizures, and certain sleep-related problems. In older adults, benzodiazepines can increase the risk of cognitive impairment, delirium, falls, and fractures. (PubMed Central (PMC))

They can be appropriate in specific medical situations, so they should not simply be stopped without professional guidance.

2. First-Generation Antihistamines

Examples include diphenhydramine, doxylamine, chlorpheniramine, and hydroxyzine.

Some older antihistamines have strong anticholinergic effects. These can contribute to confusion and other cognitive problems, particularly in older adults. (PubMed Central (PMC))

Diphenhydramine, for example, is found in some over-the-counter allergy and nighttime products, so checking ingredient labels is important.

3. Certain Tricyclic Antidepressants

Examples include amitriptyline, imipramine, and clomipramine.

Some medications in this group have substantial anticholinergic effects. The American Geriatrics Society specifically identifies strong anticholinergic medications as potentially inappropriate for many older adults because of their effects on the central nervous system. (PubMed Central (PMC))

4. Certain Bladder Medications

Some medications used to treat overactive bladder have anticholinergic properties, including oxybutynin, solifenacin, and tolterodine.

The 2023 AGS Beers Criteria lists these medications among drugs with strong anticholinergic properties. The criteria specifically note that oxybutynin has the best evidence for adverse cognitive effects, while caution is warranted with other bladder antimuscarinics as well. (PubMed Central (PMC))

5. Some Antipsychotic Medications

Antipsychotics can have significant effects on the nervous system. In older adults with dementia, the AGS Beers Criteria notes that antipsychotics are associated with an increased risk of stroke and greater cognitive decline and mortality. (PubMed Central (PMC))

These medicines can nevertheless be appropriate for certain serious psychiatric conditions. The decision to use them should be individualized by a healthcare professional.

6. Certain Antispasmodic Medications

Medications with strong anticholinergic activity—such as dicyclomine, scopolamine, atropine, and hyoscyamine—can affect cognition, particularly in susceptible older adults. (PubMed Central (PMC))

The risk can become more important when someone takes several medications with anticholinergic effects at the same time.

7. Z-Drugs Used for Insomnia

Examples include zolpidem, eszopiclone, and zaleplon.

These medications are sometimes prescribed for insomnia. In older adults, the AGS Beers Criteria recommends avoiding them because of adverse central nervous system effects and increased risks such as delirium and falls. (PubMed Central (PMC))

Does This Mean These Medicines Cause Dementia?

Not necessarily.

This distinction is extremely important.

Research has found associations between greater exposure to medications with anticholinergic effects and cognitive decline or dementia in older adults. However, the Cochrane review assessing this evidence rated its overall certainty as low, meaning the findings do not establish that these medications directly cause dementia. (Cochrane)

Some medications can also cause temporary confusion or memory problems without causing permanent dementia.

Don’t Stop a Medication Suddenly

If you recognize a medication you take on this list, don’t stop it abruptly on your own.

Some medicines—including benzodiazepines and certain other medications affecting the nervous system—may require gradual dose reduction to avoid withdrawal or other complications.

Instead, make a list of all prescription medicines, over-the-counter products, and supplements you take and ask your doctor or pharmacist whether any could be contributing to memory or concentration problems.

Final Thoughts

The safest message isn’t that seven medications “cause severe dementia and profound brain damage.” A more accurate conclusion is that certain medications can adversely affect cognition, particularly in older adults, and some medication exposures have been associated with cognitive decline or dementia. (PubMed Central (PMC))

Medication choice depends on the person’s age, diagnosis, dose, duration of treatment, other medicines, and potential benefits versus risks.

This article is for general educational purposes and does not replace advice from a doctor or pharmacist.