7 Medications That Can Affect Memory and Cognition: What You Should Know
Claims that certain medications “cause severe dementia and profound brain damage” are much too absolute. Most medicines associated with cognitive problems do not inevitably cause permanent dementia or brain damage.
However, some medications can cause confusion, delirium, sedation, memory problems, or cognitive decline, particularly in older adults. The risk can be greater with higher doses, long-term use, or combinations of several medicines that affect the brain. The 2023 American Geriatrics Society Beers Criteria specifically highlights several medication classes that can be problematic for older adults. PubMed Central (PMC)+1
Here are seven important categories to discuss with a healthcare professional.
1. Diphenhydramine and Other Strong Anticholinergic Antihistamines
Diphenhydramine is found in some allergy and nighttime cold medicines.
Other first-generation antihistamines include doxylamine, hydroxyzine, promethazine, and meclizine.
These medications have anticholinergic effects that can cause drowsiness, confusion, dry mouth, constipation, urinary problems, and other effects on the nervous system.
For older adults, the 2023 Beers Criteria recommends avoiding many of these medications because cumulative anticholinergic exposure is associated with increased risks of delirium, falls, and dementia. PubMed Central (PMC)
That doesn’t mean that taking one occasional dose will cause dementia.
The concern is particularly about repeated or cumulative exposure, especially when several anticholinergic medicines are taken together.
2. Amitriptyline and Similar Tricyclic Antidepressants
Amitriptyline and several related antidepressants have strong anticholinergic properties.
Examples include:
- Amitriptyline
- Imipramine
- Nortriptyline
- Clomipramine
- Paroxetine
- Higher-dose doxepin
The 2023 Beers Criteria recommends avoiding antidepressants with strong anticholinergic activity in older adults because they can be sedating, cause orthostatic blood-pressure changes, and produce significant anticholinergic effects. PubMed Central (PMC)
Importantly, these medications can be appropriate for certain medical conditions.
Never stop an antidepressant suddenly without medical guidance.
A doctor can determine whether the benefits outweigh the risks and whether a different treatment would be safer.
3. Benzodiazepines
Benzodiazepines include medications such as:
- Alprazolam
- Diazepam
- Lorazepam
- Clonazepam
- Temazepam
- Midazolam
These medicines can be effective for specific conditions, including certain anxiety disorders, seizures, alcohol withdrawal, and procedural sedation.
But older adults are particularly sensitive to their effects.
The Beers Criteria notes increased risks of cognitive impairment, delirium, falls, fractures, and motor-vehicle crashes in older adults taking benzodiazepines. PubMed Central (PMC)
Long-term use can also produce physical dependence.
If you’ve been taking a benzodiazepine regularly for a long time, don’t suddenly stop it. Withdrawal can be dangerous, and discontinuation generally needs to be gradual and medically supervised.
4. Z-Drugs Used for Insomnia
Medications such as zolpidem, zaleplon, and eszopiclone are sometimes called Z-drugs.
They’re prescribed for insomnia, but they act on the brain in ways related to benzodiazepines.
In older adults, they can increase the risk of confusion, falls, fractures, and other adverse effects.
The 2023 Beers Criteria recommends avoiding these medications in older adults because they provide relatively limited improvement in sleep while carrying important risks. PubMed Central (PMC)
If you’re relying on a sleeping pill every night, it’s worth discussing whether there are safer long-term approaches.
5. Strong Anticholinergic Bladder Medications
Some medications used to treat overactive bladder work by blocking acetylcholine.
Examples include oxybutynin, solifenacin, tolterodine, and related drugs.
The 2023 Beers Criteria identifies these medications as having strong anticholinergic properties. It specifically notes that oxybutynin has the best evidence for adverse cognitive effects among bladder antimuscarinics, although caution is warranted with the entire class. PubMed Central (PMC)
This doesn’t mean everyone taking one will develop dementia.
If bladder symptoms require treatment, a clinician can consider the person’s age, cognitive health, other medications, kidney function, and available alternatives.
6. Antipsychotic Medications
Antipsychotics include medications such as:
- Risperidone
- Olanzapine
- Quetiapine
- Haloperidol
- Aripiprazole
These are important medications for certain psychiatric and neurological conditions.
But their use in older adults with dementia requires particular caution.
The Beers Criteria notes that antipsychotics are associated with an increased risk of stroke, cognitive decline, and mortality in people with dementia. They generally shouldn’t be used simply to control behavioral symptoms of dementia unless non-drug approaches have failed or the person poses a substantial risk of harm. PubMed Central (PMC)
That is very different from saying antipsychotics automatically cause dementia.
They can be essential medications for some people, and their risks and benefits must be considered individually.
7. Certain Opioids and Other CNS-Active Medications
Opioid pain medications can cause sedation and delirium, particularly in older adults.
The concern becomes even greater when opioids are combined with other medications that suppress the central nervous system.
For example, the Beers Criteria recommends avoiding the combination of opioids and benzodiazepines because of the risk of severe sedation, respiratory depression, coma, and death. PubMed Central (PMC)
It also recommends minimizing combinations involving three or more central-nervous-system-active medications because of increased risks of falls and fractures. PubMed Central (PMC)+1
This is one reason medication reviews become especially important when someone takes many prescriptions.
Dementia and Medication-Related Confusion Aren’t the Same Thing
This distinction is extremely important.
A medication can cause temporary confusion or delirium without causing permanent dementia.
For example, an older person might become confused after taking a sedating medication, developing an infection, becoming dehydrated, or experiencing a medication interaction.
Once the underlying problem is treated, the confusion may improve.
Dementia, by contrast, involves persistent impairment in thinking and everyday functioning.
So if an older person suddenly becomes confused, don’t assume they have developed dementia.
Sudden confusion deserves medical evaluation.
The Bigger Issue May Be the Combination
Sometimes the problem isn’t one medication.
An older person might take a sleep medication, an antihistamine, an antidepressant, an opioid, and a bladder medication—all of which can affect the nervous system in different ways.
The effects can add up.
The 2023 Beers Criteria specifically warns about combining multiple anticholinergic medications and about using three or more CNS-active medication classes together. PubMed Central (PMC)
That’s why a complete medication review can be more useful than simply asking, “Which one of my medicines causes dementia?”
Don’t Stop Important Medications on Your Own
This is perhaps the most important message.
If you recognize one of your medications on this list, don’t suddenly stop taking it.
Some medications need to be tapered. Others are treating serious conditions, and stopping them without supervision can be dangerous.
Instead, ask your doctor or pharmacist:
- Is this medication still necessary?
- Is the dose appropriate for my age?
- Could it be contributing to memory problems or confusion?
- Am I taking other medicines with similar effects?
- Is there a safer alternative?
- Can the medication be reduced gradually?
A pharmacist can often perform a useful medication review, particularly when someone takes many prescriptions and over-the-counter products.
The Bottom Line
There isn’t a scientifically accurate list of seven medications that inevitably cause “severe dementia and profound brain damage.”
A more accurate message is that certain medications can increase the risk of cognitive impairment, delirium, sedation, falls, or cognitive decline, particularly in older adults.
The major categories to discuss with a healthcare professional include:
- Strong anticholinergic antihistamines
- Tricyclic and other strongly anticholinergic antidepressants
- Benzodiazepines
- Z-drugs for insomnia
- Strong anticholinergic bladder medications
- Antipsychotics
- Opioids and combinations of multiple CNS-active medicines
The goal isn’t to frighten people away from necessary treatment.
It’s to make sure every medication has a clear purpose, the lowest appropriate dose, and a favorable balance between benefits and risks.
If you or a family member has developed new memory problems, excessive sleepiness, falls, or sudden confusion, ask for a medication review before assuming that dementia is the explanation. PubMed Central (PMC)
