Alert: 8 Types of Medicines That Can Affect Memory and Thinking
Some medicines can cause confusion, drowsiness, memory problems, or other cognitive side effects, particularly in older adults. However, it would be inaccurate to say that eight specific medicines “cause serious dementia.” Evidence is stronger for some drug classes than others, and medication-related confusion can sometimes be reversible.
1. Strong Anticholinergic Medicines
This is one of the most important groups to know about. Anticholinergic drugs can interfere with the brain chemical acetylcholine and may impair cognition, particularly in older adults.
They are found in medicines used for conditions such as allergies, bladder problems, depression, and some gastrointestinal problems. Long-term cumulative exposure to strong anticholinergics has been associated with a higher risk of dementia in observational research.
2. Certain Antihistamines
Some older antihistamines have strong anticholinergic effects and can cause:
- Drowsiness
- Confusion
- Difficulty concentrating
- Memory problems
The National Institute on Aging specifically lists some antihistamines among medicines that can impair cognition in older adults.
3. Some Sleep Medicines
Certain sleep medicines can cause next-day drowsiness and confusion. In older adults, regular use can also increase the risk of falls.
People with dementia may be particularly sensitive to these effects.
4. Benzodiazepines
Benzodiazepines are used for conditions including anxiety, insomnia, seizures, and other medical situations.
In older adults, they can contribute to memory loss, confusion, impaired thinking, dizziness, and falls. The NIA recommends that their risks and benefits be carefully considered.
5. Some Antipsychotic Medicines
Antipsychotic medicines can be appropriate for specific medical conditions, but they require particular caution in older adults and people who already have dementia.
They can cause sedation, dizziness, confusion, and other serious adverse effects. They should be used only when the potential benefits outweigh the risks and under appropriate medical supervision.
6. Some Muscle Relaxants
Certain muscle relaxants can affect the central nervous system and may cause:
- Sleepiness
- Dizziness
- Confusion
- Reduced alertness
The NIA identifies muscle relaxants among medication groups that can impair cognition in older adults.
7. Some Medicines for Urinary Problems
Certain medications used to treat urinary incontinence have anticholinergic effects.
Because acetylcholine is important for normal cognitive function, medicines with substantial anticholinergic activity can be particularly concerning in older adults. Doctors may consider alternatives when appropriate.
8. Combinations of Several Brain-Active Medicines
Sometimes the concern isn’t one medication by itself but several medicines that affect the central nervous system at the same time.
Combinations involving sedatives, antidepressants, antipsychotics, opioids, or anti-seizure medicines can increase the risk of adverse effects such as confusion, falls, and excessive sedation.
Does Taking These Medicines Mean You Will Develop Dementia?
No.
An association between a medication and dementia risk doesn’t prove that the medication directly causes dementia in every person who takes it. Dementia has many possible causes and risk factors, and researchers are still studying how medications, underlying illnesses, age, and other factors interact.
Some medicines can also cause temporary confusion or delirium, which is different from dementia.
Never Stop a Prescription Suddenly
If you or a family member takes one of these medications, don’t stop it suddenly or change the dose without medical advice. Some medicines require gradual dose reduction, and stopping them abruptly can cause problems.
Instead, ask a doctor or pharmacist to review the complete medication list and determine whether any medicine could be contributing to memory or thinking problems.
Bottom Line
The biggest concern is not that certain medicines automatically “cause severe dementia.” Rather, some medications—especially those with strong anticholinergic or sedating effects—can impair memory and thinking and may be associated with increased dementia risk with prolonged exposure.
If new confusion or significant memory problems appear after starting or increasing a medicine, tell a healthcare professional rather than assuming it is simply normal aging.
