Could a medication you take every day be affecting your memory without you realizing it?
Millions of people rely on prescription medications and over-the-counter drugs to manage allergies, depression, sleep problems, bladder conditions, and other everyday health concerns.
Most people focus on whether these treatments relieve their symptoms. Far fewer consider what certain medications might mean for long-term brain health, memory, and cognitive function.
But scientists have been investigating a surprising connection: some commonly used medications have been associated with an increased risk of dementia, particularly when taken regularly over many years.
The medications attracting attention belong to a group known as anticholinergic drugs.
And some of them may already be sitting in your medicine cabinet.
Before you become alarmed, there is something important to understand: researchers have identified associations, not definitive proof that these medications cause dementia.
Here are eight categories worth knowing about — and what the scientific evidence actually says.
What Are Anticholinergic Drugs, and Why Do They Matter?
Your brain depends on chemical messengers to communicate, process information, store memories, and control essential bodily functions.
One of these messengers is called acetylcholine.
Acetylcholine plays an important role in learning, memory, attention, and communication between nerve cells.
Anticholinergic medications work by blocking certain effects of acetylcholine.
This can be helpful when treating medical conditions such as an overactive bladder, allergies, movement disorders, or other health problems.
However, some of these medications can also affect the central nervous system, particularly in older adults.
Researchers have questioned whether prolonged exposure to strongly anticholinergic medications could contribute to memory problems or an increased likelihood of developing dementia.
A major study published in JAMA Internal Medicine in 2019 examined medical records involving more than 280,000 people.
Researchers found that higher cumulative exposure to several classes of strong anticholinergic drugs was associated with increased odds of dementia.
The findings raised important questions about medications many people use for years.
1. Certain Antidepressants — A Potentially Overlooked Connection to Memory Loss
Antidepressants help millions of people manage depression and other mental health conditions.
However, not all antidepressants affect the brain in the same way.
Some older antidepressants, particularly tricyclic antidepressants, have strong anticholinergic properties.
Examples include:
- Amitriptyline
- Certain other tricyclic antidepressants
- Paroxetine, an SSRI with comparatively notable anticholinergic activity
Research has linked greater cumulative exposure to strongly anticholinergic antidepressants with higher odds of dementia.
But there is an important complication.
Depression itself may be associated with dementia risk, and symptoms of depression can sometimes appear before dementia is diagnosed.
This makes it difficult to establish whether medication exposure, underlying illness, or a combination of factors explains the observed association.
What you should know: If you take an antidepressant, do not discontinue it abruptly. Ask your healthcare provider whether your medication has significant anticholinergic effects and whether another treatment would be appropriate.
2. Overactive Bladder Medications — Why Scientists Are Paying Attention
Medications prescribed for an overactive bladder can help control urinary urgency, frequency, and incontinence.
Some of these treatments work by blocking muscarinic receptors and are classified as anticholinergic medications.
Common examples include:
- Oxybutynin
- Tolterodine
- Solifenacin
Several observational studies have associated prolonged exposure to bladder anticholinergics with a higher incidence of dementia.
However, research has not produced entirely consistent results.
A large Danish study published in 2025 found that anticholinergic bladder medications were associated with increased dementia risk when compared with non-use.
Interestingly, the same increase was not observed when researchers compared these medications directly with mirabegron, a different type of bladder treatment.
These findings suggest that underlying health conditions and the choice of comparison group can significantly influence the results.
What you should know: If you have been taking bladder medication for years, ask your doctor whether your treatment remains the best option for your situation.
3. Older Allergy Medications — Could Your Antihistamine Affect Brain Health?
Allergy medications are among the most familiar drugs found in household medicine cabinets.
But some first-generation antihistamines have strong anticholinergic effects.
One well-known example is diphenhydramine, an ingredient found in certain allergy medicines and nighttime sleep products.
These older antihistamines can cause drowsiness, reduced alertness, and short-term cognitive impairment, particularly in older adults.
Long-term studies investigating cumulative anticholinergic exposure have also raised concerns about possible associations with dementia.
Does taking an allergy pill occasionally mean you are damaging your brain?
No.
The evidence does not establish that an occasional dose causes dementia.
The greater concern involves repeated exposure, especially among older people taking several medications with anticholinergic properties.
What you should know: If you frequently use sedating antihistamines, speak with your pharmacist about whether a less anticholinergic alternative would be suitable.
4. Parkinson’s Disease Medications — A Complicated Relationship With Dementia
Parkinson’s disease affects movement, coordination, and, in some patients, cognitive function.
Certain medications used to treat Parkinson’s symptoms have anticholinergic properties.
Researchers have found an association between high cumulative exposure to strongly anticholinergic antiparkinson medications and increased odds of dementia.
However, there is an essential distinction.
Parkinson’s disease itself can increase the likelihood of cognitive impairment and dementia.
This means researchers cannot automatically attribute dementia diagnoses to the medications used to manage the condition.
For patients living with Parkinson’s disease, the benefits of symptom control must be balanced against potential adverse effects.
What you should know: Never change Parkinson’s medications without consulting your neurologist.
5. Certain Antipsychotic Medications — What Studies Have Discovered
Some antipsychotic medications used to treat psychiatric disorders have anticholinergic effects.
The 2019 JAMA Internal Medicine study reported an association between higher cumulative exposure to strongly anticholinergic antipsychotics and increased odds of dementia.
But interpreting this relationship is challenging.
Psychiatric and neurological conditions can themselves affect memory, thinking, and cognitive health.
Researchers must therefore distinguish the possible effects of medication from those of the underlying medical condition.
Not all antipsychotic medications have the same anticholinergic activity.
What you should know: Antipsychotic treatment should only be adjusted under medical supervision. Abrupt changes can cause serious health consequences.
6. Some Anti-Seizure Medications — Another Category Worth Reviewing
Medications used to manage epilepsy and seizures are essential treatments for many patients.
Some anti-seizure drugs can contribute to a person’s overall anticholinergic burden.
In a large observational study, greater cumulative exposure to certain strongly anticholinergic antiepileptic medications was associated with increased odds of dementia.
However, this finding does not mean that anti-seizure medications as a whole cause dementia.
Different drugs act through different mechanisms, and epilepsy itself can influence cognitive function.
For many patients, effective seizure control is crucial for protecting their health and safety.
What you should know: Never stop seizure medication suddenly. If you are concerned about memory changes, discuss them with your neurologist.
7. Medicines for Nausea, Dizziness, and Motion Sickness
Medications used to relieve nausea, vertigo, and motion sickness may seem unrelated to brain health.
However, certain products in these categories have anticholinergic properties.
This creates a problem that patients may not recognize.
A person might use one medication for allergies, another for sleep, and another for dizziness.
Individually, each treatment may seem routine.
Together, they can increase the person’s total anticholinergic burden.
Researchers have found that cumulative exposure to strong anticholinergic medications may be associated with a higher incidence of dementia.
That is why reviewing all medications matters more than focusing exclusively on a single pill.
What you should know: Tell your doctor or pharmacist about every medication you use, including occasional treatments and nonprescription products.
8. Over-the-Counter Sleep Aids — The Hidden Ingredient Many People Miss
Millions of people struggle to get a good night’s sleep.
Some turn to over-the-counter sleep aids, assuming that products available without a prescription are safe for regular use.
But certain nighttime sleep products contain older sedating antihistamines with strong anticholinergic effects.
Examples of ingredients found in some products include:
- Diphenhydramine
- Doxylamine
These substances can cause drowsiness and may also affect attention and memory, particularly among older adults.
The concern becomes more relevant when these medications are used frequently or combined with other anticholinergic drugs.
What you should know: If you regularly depend on an OTC sleep aid, speak with a healthcare professional about its ingredients, duration of use, and possible alternatives.
What Does the Research Really Say About Anticholinergic Drugs and Dementia?
Scientists have investigated the relationship between anticholinergic medications and cognitive decline for years.
One important finding involves cumulative exposure.
In simple terms, this means the combined amount of medication a person has taken over time.
Some studies have suggested that people with the greatest cumulative exposure to strong anticholinergic medications have higher rates of dementia than those with little or no exposure.
A large systematic review and meta-analysis covering more than 1.5 million participants also reported associations between anticholinergic use and increased risks of dementia and Alzheimer’s disease.
However, observational research has limitations.
People taking these medications may have underlying conditions that independently influence dementia risk.
Sometimes, a medication may even be prescribed for symptoms that occur during the early stages of an undiagnosed neurological condition.
For these reasons, scientists continue investigating whether the medications themselves contribute to dementia or whether other factors explain part of the association.
The key point: A statistical association does not prove that a medication causes dementia.
Does Taking One of These Medications Mean You Will Develop Dementia?
No. And this distinction is extremely important.
Taking a medication on this list does not mean you will develop Alzheimer’s disease or another form of dementia.
Your individual situation depends on several factors, including:
- The specific medication and its anticholinergic strength
- The prescribed dose
- How long you have taken it
- Your age and overall health
- Other medications you use
- Existing neurological or medical conditions
- Your individual risk factors for dementia
The findings are most relevant when considering prolonged exposure to medications with strong anticholinergic effects.
Short-term or occasional use should not automatically be treated as equivalent to years of regular exposure.
Warning Signs Worth Discussing With Your Doctor
Certain medications can produce cognitive side effects, particularly in older adults.
Symptoms worth reporting include:
- New or worsening confusion
- Increased forgetfulness
- Difficulty concentrating
- Unusual daytime drowsiness
- Changes in alertness or attention
These symptoms do not necessarily indicate dementia.
They can have many possible causes, including medication side effects, sleep problems, infections, and other medical conditions.
Sudden confusion, in particular, requires prompt medical evaluation.
If you notice changes in memory or thinking after starting or adjusting a medication, contact your healthcare professional.
How to Protect Your Brain Health Without Making Dangerous Medication Changes
Learning about possible medication risks can be unsettling.
But the solution is not to throw away your prescriptions or stop taking medication.
In fact, suddenly discontinuing certain antidepressants, psychiatric drugs, Parkinson’s treatments, or seizure medications can be dangerous.
A safer approach is to request a comprehensive medication review.
Bring a complete list of your prescription medicines, over-the-counter products, and supplements.
Ask your doctor or pharmacist:
“Am I taking any medications with strong anticholinergic effects, and are there safer alternatives for my situation?”
Your healthcare professional can evaluate the benefits, potential risks, dosage, duration of treatment, and possible interactions.
In some cases, an alternative treatment may be appropriate. In others, continuing the current medication may provide greater benefits than changing it.
The decision should always be individualized.
The Bottom Line: Your Everyday Medications Deserve a Second Look
The connection between certain medications and dementia risk is an important area of ongoing medical research.
Several large studies have found associations between long-term exposure to strong anticholinergic medications and a higher incidence of dementia.
These findings are especially relevant to some antidepressants, bladder treatments, antiparkinson medications, and other drugs with significant anticholinergic activity.
But there is no evidence that everyone taking these medications will develop dementia, and researchers have not established a direct causal relationship for all the medication categories discussed.
The most useful action you can take is simple: Know what you are taking, understand why you are taking it, and review your medications regularly with a qualified healthcare professional.
Protecting your brain health does not mean avoiding necessary treatment.
It means making informed decisions based on reliable medical evidence.
Scientific References
- Coupland et al. (2019). Anticholinergic Drug Exposure and the Risk of Dementia: A Nested Case-Control Study. JAMA Internal Medicine. https://doi.org/10.1001/jamainternmed.2019.0677
- Pourhadi et al. (2025). Bladder drugs and risk of dementia: Danish nationwide active comparator study. BMJ Medicine. https://bmjmedicine.bmj.com/content/4/1/e001125
- Gray et al. (2015). Cumulative Use of Strong Anticholinergics and Incident Dementia. JAMA Internal Medicine. https://doi.org/10.1001/jamainternmed.2014.7663
Medical Disclaimer
This article is intended for general educational and informational purposes only. It does not constitute medical advice, diagnosis, or treatment. Never stop, start, or change the dosage of a prescribed medication without consulting your doctor or another qualified healthcare professional.
