What are the 9 prescription drugs that cause dementia?

October 6, 2025 •

5 min read

A growing body of research has linked several classes of common prescription drugs to an increased risk of developing dementia [1.2.3]. While no medication is a confirmed cause, long-term use of certain drugs, particularly those with anticholinergic properties, has been associated with a higher dementia risk [1.2.2].

Quick Summary

An examination of medication classes linked to a higher risk of dementia. This overview details the types of drugs, their mechanisms, and the importance of discussing medication risks with a healthcare provider.

Key Points

Anticholinergics are a top concern: Drugs that block the neurotransmitter acetylcholine show a strong link to increased dementia risk with long-term use [1.2.2, 1.3.1].
Benzodiazepines and sleep aids: Long-term use of medications for anxiety and sleep, including benzodiazepines and 'Z-drugs', may increase dementia risk, though the evidence is debated [1.4.2, 1.5.1].
Risk is cumulative: For many of these drug classes, the risk of dementia increases with higher doses and longer durations of use [1.2.2, 1.3.3].
Antipsychotic risks: Antipsychotic medications carry significant risks for older adults, including an increased risk of both dementia and mortality, and are subject to FDA warnings [1.7.2, 1.7.3].
Consult your doctor: It is critical to never stop or alter medication without consulting a healthcare provider, as abrupt changes can be dangerous [1.2.5].
Controversy exists: The link between some drug classes, like statins, and cognitive decline is controversial, with studies showing conflicting results [1.10.1, 1.10.4].
It's about classes, not a fixed number: Research points to categories of drugs rather than a specific list of nine individual medications that pose a risk [1.2.3].

Important Disclaimer

The information in this article is for informational purposes only and should not be considered medical advice. Do not stop or change any medication without first consulting with your healthcare provider. Abruptly stopping some medications can be harmful [1.2.5].

While the headline question is specific, scientific research points to classes of drugs that are associated with an increased risk of dementia rather than a definitive list of individual drugs that cause it [1.2.3]. The link is often related to the cumulative dose and duration of use [1.2.2]. The American Geriatrics Society has cautioned against prescribing some of these drug classes to older adults when possible [1.2.3].

Here are some of the key drug classes and their association with cognitive decline and dementia:

1. Anticholinergics

This is the most widely studied class of drugs regarding dementia risk. Anticholinergics work by blocking acetylcholine, a neurotransmitter crucial for memory and learning functions in the brain [1.2.2, 1.3.1]. Chronic use is associated with a significantly higher risk of dementia. One study found that taking a strong anticholinergic for the equivalent of three years or more was associated with a 54% higher dementia risk [1.2.2, 1.3.1].

Common Uses: Allergies, colds, depression, overactive bladder, and Parkinson's disease symptoms [1.2.2, 1.2.5].
Examples: Diphenhydramine (found in Benadryl and over-the-counter sleep aids), oxybutynin (for bladder control), and some tricyclic antidepressants like amitriptyline [1.2.1, 1.3.1, 1.9.1].

2. Benzodiazepines

Commonly prescribed for anxiety and insomnia, benzodiazepines enhance the effect of the neurotransmitter GABA, which slows brain activity [1.4.2, 1.4.5]. Studies have shown a link between long-term use and an increased risk of Alzheimer's disease. One study reported that use for three to six months raised the risk by 32%, and use for more than six months raised it by 84% [1.4.2]. However, other recent research has found little to no evidence of a causal link, suggesting the association may be due to other underlying health conditions [1.4.1, 1.4.3, 1.4.4].

Common Uses: Anxiety, insomnia, seizures, muscle relaxation [1.4.5].
Examples: Alprazolam (Xanax), lorazepam (Ativan), and diazepam (Valium).

3. 'Z-Drugs' (Non-benzodiazepine hypnotics)

These sleep medications are chemically different from benzodiazepines but act on similar brain pathways [1.5.4]. Some research suggests that high doses of Z-drugs are associated with an increased risk of dementia, particularly in women [1.5.1, 1.5.4]. Other studies, however, have not found a significant association when adjusting for other factors [1.5.2, 1.5.3].

Common Uses: Insomnia [1.5.4].
Examples: Zolpidem (Ambien), eszopiclone (Lunesta), and zaleplon (Sonata) [1.5.5].

4. Antipsychotics

Used for conditions like schizophrenia and bipolar disorder, and sometimes off-label for agitation in dementia patients, these drugs have been linked to increased dementia risk [1.7.2, 1.7.3]. The FDA has issued a black box warning about their use in elderly patients with dementia due to an increased risk of death [1.7.2, 1.7.4]. One study found that exposure to any antipsychotics conferred increased risks of all-cause dementia and vascular dementia [1.7.3].

Common Uses: Schizophrenia, bipolar disorder, and sometimes agitation [1.7.2].
Examples: Risperidone, quetiapine, olanzapine, and haloperidol [1.7.1, 1.7.3].

5. Anticonvulsants (Antiepileptic Drugs)

Certain antiepileptic drugs (AEDs) are known to have cognitive side effects, including memory problems and difficulty concentrating [1.8.2, 1.8.3]. Some of these drugs also have strong anticholinergic properties, contributing to dementia risk [1.3.4, 1.3.5]. One study found that higher serum levels of drugs like carbamazepine and phenytoin were associated with impaired memory retention [1.8.1].

Common Uses: Seizures (epilepsy), and sometimes nerve pain or bipolar disorder [1.8.4].
Examples: Carbamazepine, phenytoin, valproate, and topiramate [1.8.1, 1.8.4].

6. Opioids

Chronic opioid use for non-cancer pain has been associated with cognitive decline and an increased risk of dementia [1.6.2, 1.6.3]. A large study found that regular opioid use was associated with a 20% higher risk of all-cause dementia, and strong opioid use was linked to a 72% higher risk [1.6.4]. The mechanism may involve impaired function of the hippocampus and other central nervous system sites [1.6.4].

Common Uses: Moderate to severe pain management [1.6.3].
Examples: Morphine, oxycodone, and hydrocodone.

7. Corticosteroids

Systemic corticosteroids like prednisone can cause mood and cognitive changes, including deficits in verbal or declarative memory [1.9.1]. High doses are associated with a greater risk of psychiatric side effects [1.9.1]. While often reversible, a condition known as "steroid dementia syndrome" has been described, involving deficits in memory, attention, and executive function [1.9.5].

Common Uses: Treating inflammation for conditions like asthma and arthritis [1.9.5].
Examples: Prednisone, dexamethasone, hydrocortisone [1.9.1].

8. Certain Antidepressants

While some newer antidepressants (SSRIs) were once thought to potentially have a protective effect, recent research has challenged this. Tricyclic antidepressants have strong anticholinergic properties and are linked to dementia risk [1.3.2, 1.2.2]. A 2025 study also found that use of certain SSRIs, such as citalopram and escitalopram, was associated with faster cognitive decline in patients who already had dementia [1.2.4].

Common Uses: Depression, anxiety disorders [1.2.4].
Examples: Amitriptyline (tricyclic), citalopram (SSRI), sertraline (SSRI), escitalopram (SSRI) [1.2.4].

9. Statins (Controversial)

The link between statins and cognitive function is highly debated. The FDA issued a warning about rare reports of reversible memory loss [1.10.1, 1.10.2]. However, many large-scale observational studies and randomized trials have found no effect or even a protective effect of statins on cognitive function, suggesting they may lower dementia risk [1.10.1, 1.10.4, 1.10.5]. The evidence remains inconsistent [1.10.4].

Common Uses: Lowering cholesterol [1.10.5].
Examples: Atorvastatin (Lipitor), simvastatin (Zocor), rosuvastatin (Crestor) [1.10.4].

Drug Class Comparison Table


Drug Class	Primary Use(s)	Strength of Association with Dementia Risk	Common Examples
Anticholinergics	Allergies, Bladder Control, Depression	Strong, especially with long-term, cumulative use [1.2.2, 1.3.3].	Diphenhydramine, Oxybutynin
Benzodiazepines	Anxiety, Insomnia	Moderate to Strong, but debated. Risk increases with duration of use [1.4.2, 1.4.5]. Some studies find no causal link [1.4.3].	Alprazolam, Lorazepam
'Z-Drugs'	Insomnia	Weak to Moderate. Some studies show risk at high doses [1.5.1, 1.5.4].	Zolpidem, Eszopiclone
Antipsychotics	Psychosis, Agitation	Strong. Associated with increased risk of dementia and mortality in the elderly [1.7.3, 1.7.5].	Risperidone, Quetiapine
Anticonvulsants	Epilepsy, Nerve Pain	Moderate. Some have anticholinergic effects [1.3.5]. Side effects include cognitive impairment [1.8.2].	Carbamazepine, Phenytoin
Opioids	Pain Management	Moderate. Chronic use is associated with higher dementia risk [1.6.4].	Oxycodone, Morphine
Corticosteroids	Inflammation	Weak to Moderate. Can cause reversible cognitive deficits; "steroid dementia" is rare [1.9.1, 1.9.5].	Prednisone, Dexamethasone
Antidepressants	Depression, Anxiety	Varies. Strong risk for tricyclics. Emerging risk for some SSRIs [1.2.4, 1.3.2].	Amitriptyline, Citalopram
Statins	High Cholesterol	Controversial / Inconsistent. Some reports of memory loss, but many studies show no link or a protective effect [1.10.1, 1.10.4].	Atorvastatin, Simvastatin

Conclusion

While a direct causal link is difficult to prove for any single medication, a significant body of evidence shows that long-term use of certain drug classes, especially those with anticholinergic effects, is associated with an increased risk of dementia. The risk is often dose-dependent and increases with the duration of use [1.2.2]. It is crucial for individuals, especially older adults, to regularly review their medications with their healthcare provider. This allows for a careful consideration of the benefits versus the potential cognitive risks and exploration of safer alternatives when available [1.2.5]. Never stop taking a prescribed medication without medical supervision [1.2.5].

For further reading, you may find this resource from Harvard Health Publishing informative: https://www.health.harvard.edu/mind-and-mood/two-types-of-drugs-you-may-want-to-avoid-for-the-sake-of-your-brain

Frequently Asked Questions

No. These drugs are associated with an increased risk of dementia, not a guarantee. The risk is influenced by factors like the dose, duration of use, and individual health factors [1.2.2]. Many people use these medications without developing dementia.

Anticholinergic drugs are medications that block the action of acetylcholine, a neurotransmitter involved in learning, memory, and muscle contraction. They are used for various conditions, including allergies, depression, and overactive bladder [1.3.1, 1.2.2].

The link is not definitively proven and remains controversial. While some large studies have shown a strong association between long-term benzodiazepine use and a higher risk of dementia [1.4.2, 1.4.5], other recent studies have found no causal relationship, suggesting the link may be due to confounding factors like underlying anxiety or depression [1.4.1, 1.4.3].

Yes, some OTC medications, particularly those with strong anticholinergic effects like the antihistamine diphenhydramine (found in Benadryl) and certain sleep aids, have been linked to an increased risk of dementia with long-term use [1.3.1, 1.2.3].

No. You should never stop taking a prescribed medication without consulting your doctor. Abruptly stopping some drugs can have serious health consequences. Discuss your concerns with your healthcare provider to weigh the risks and benefits and explore potential alternatives [1.2.5].

The cognitive impairment, such as memory loss, from some of these drugs (like statins or corticosteroids) is often reported as reversible upon discontinuing the medication [1.10.1, 1.9.1]. However, the increased risk of developing a progressive dementia like Alzheimer's associated with long-term use may not be.

Antipsychotics are associated with an increased risk of stroke and death in elderly patients with dementia-related psychosis [1.7.2]. This led the FDA to issue its strictest warning (a 'boxed warning') against their use in this population [1.7.4].