Some medicines can affect memory, attention, or thinking, particularly in older adults. Learn which medication groups may contribute to cognitive problems and why you should never stop a prescription without medical advice.
As we get older, it is common to become more concerned about forgetfulness and memory changes. Sometimes these changes are related to aging or an underlying medical condition, but medications can also affect cognition.
The Main Groups of Medicines That May Affect Memory and Could Be Linked to Dementia Risk
Some medicines may cause temporary confusion, drowsiness or memory problems. Research has also found associations between long-term exposure to certain medication groups—especially medicines with anticholinergic effects—and a higher risk of dementia. However, an association does not prove that the medicine directly causes dementia.
This is particularly important for older adults, who may take several medications at the same time.
1. Anticholinergic Medicines
This is one of the most important groups to know about.
Anticholinergic medicines block the action of acetylcholine, a chemical messenger involved in memory, learning and other brain functions.
They are used for many different conditions, including allergies, bladder problems, depression, gastrointestinal problems and some respiratory conditions.
Examples can include certain:
- Antihistamines
- Bladder-control medicines
- Antidepressants
- Antispasmodics
- Medicines used for Parkinson’s disease
The overall exposure from multiple anticholinergic medicines is sometimes called the anticholinergic burden.
Studies have found an association between greater anticholinergic exposure and subsequent cognitive decline or dementia, although researchers cannot conclude from these observational findings that the medicines themselves are the direct cause.
2. Some Older Antihistamines
Some first-generation antihistamines have strong anticholinergic effects.
Examples include medicines containing diphenhydramine and similar drugs, which are sometimes found in allergy, cold and nighttime sleep products.
These medicines can cause drowsiness, confusion and impaired attention, particularly in older adults. The National Institute on Aging specifically recommends reviewing antihistamines when assessing possible medication-related cognitive problems.
This is one reason it is important to check the ingredients of over-the-counter “nighttime” or “PM” products rather than assuming they are harmless.
3. Benzodiazepines
Benzodiazepines are prescription medicines commonly used for anxiety, panic disorders and sometimes insomnia.
Examples include:
- Diazepam
- Lorazepam
- Alprazolam
- Clonazepam
These medicines can cause sedation, impaired attention and memory problems. Research has found associations between benzodiazepine exposure and cognitive impairment, particularly with longer-term use in older adults.
They can also cause dependence, so they should not be stopped suddenly without medical supervision.
4. Certain Sleeping Medicines
Some sleep medicines, including the so-called Z-drugs such as zolpidem, can affect alertness, memory and coordination.
These effects can be particularly concerning in older adults because medication-related sedation may increase the risk of falls and confusion.
If you regularly need a sleeping medicine, discuss the long-term benefits and risks with your healthcare professional.
5. Certain Antidepressants
Some antidepressants—particularly those with significant anticholinergic properties, such as certain tricyclic antidepressants—can affect memory and attention.
However, antidepressants are a diverse group, and they should not all be considered equivalent.
A recent systematic review found evidence of cognitive decline associated with cumulative benzodiazepine use and with antidepressants, particularly those with anticholinergic properties, in older adults.
Depression itself can also cause concentration and memory difficulties, so stopping an effective antidepressant without medical guidance can make cognitive symptoms worse.
6. Certain Antipsychotic Medicines
Antipsychotic medications can affect alertness and cognition, and research has found associations between their use and cognitive decline in older adults.
However, these medicines may be essential for some people with serious psychiatric or neurological conditions. The decision to continue, change or stop one requires an individualized assessment of benefits and risks.
7. Some Opioid Pain Medicines
Opioids can cause drowsiness, confusion and impaired attention, particularly when starting treatment, increasing the dose, or combining them with other sedating medicines.
The cognitive effects can be especially important in older adults or people taking multiple medications.
This does not mean people who need opioid pain relief should simply stop taking it. Pain itself can interfere with sleep, concentration and quality of life.
Why Older Adults Are More Vulnerable
Older adults are often more sensitive to medicines because the body processes drugs differently with age.
The risk can also increase when someone takes several medications with similar effects.
For example, a person might unknowingly take an anticholinergic antihistamine for allergies while also taking another anticholinergic medicine for bladder symptoms. The combined effect may be more important than either medication considered separately.
What Should You Do If You’re Worried About Memory?
Don’t immediately stop your medication.
Instead, make a complete list of everything you take, including:
- Prescription medicines
- Over-the-counter medicines
- Sleep aids
- Allergy medicines
- Pain medicines
- Vitamins
- Herbal supplements
Take the list to your doctor or pharmacist and ask:
“Could any of these medicines be affecting my memory or thinking?”
A healthcare professional can determine whether a medicine could be contributing to your symptoms and whether a lower dose, different medication or alternative treatment might be appropriate.
Never Stop Certain Medicines Suddenly
Some medicines—including benzodiazepines and several other prescription drugs—can cause withdrawal symptoms or other complications if stopped abruptly.
Never discontinue a prescribed medication simply because you read that it might affect memory.
Your doctor may be able to gradually reduce the dose or substitute another treatment when appropriate.
Could Medication-Related Memory Problems Improve?
Sometimes.
If a medication is contributing to confusion or cognitive impairment, adjusting the medication under medical supervision may improve symptoms.
But medication-related cognitive problems and dementia are not the same thing. A person can have temporary medication-related confusion without having dementia, while dementia can have many underlying causes.
That’s why persistent or progressive memory problems deserve proper medical evaluation.
The Bottom Line
Several medication groups can affect memory, attention or thinking, particularly in older adults. The groups that deserve particular attention include anticholinergic medicines, some antihistamines, benzodiazepines, certain sleeping medicines, some antidepressants, antipsychotics and opioids.
The strongest concern regarding a possible long-term dementia association is currently around cumulative anticholinergic exposure, although the evidence does not prove that these medicines directly cause dementia.
The safest approach is not to stop medication on your own. Instead, ask a doctor or pharmacist to review your complete medication list—especially if you have noticed new or worsening memory problems.
This article is for educational purposes and does not replace individualized medical advice. Medication decisions should be made with a qualified healthcare professional.