Table of Contents

• Why Medications and Brain Health Matter
• How Researchers Study Drug-Cognitive Decline Links
• Medication 1: Anticholinergic Drugs
• Medication 2: Benzodiazepines
• Medication 3: Non-Benzodiazepine Sleep Aids (Z-drugs)
• Medication 4: First-Generation Antihistamines
• Medication 5: Tricyclic Antidepressants
• Medication 6: Proton Pump Inhibitors (PPIs)
• Medication 7: Opioid Analgesics
• The Research Summary: Strength of Evidence Table
• What You Should Do: Talking to Your Doctor
• Conclusion: Knowledge Is the Starting Point
• Frequently Asked Questions
• External References and Further Reading

Why Medications and Brain Health Matter

By the time most Americans reach their sixties, they are taking multiple prescription and over-the-counter medications daily. The average Medicare beneficiary fills more than 20 prescriptions per year. For the vast majority of these medicines, the benefits are clear and well-established. They control blood pressure, manage diabetes, treat infections, relieve pain, and address hundreds of other conditions that would otherwise significantly reduce quality of life.

But a growing body of peer-reviewed research has identified a subset of commonly used drug classes that are associated, in observational studies and meta-analyses, with elevated long-term risk of cognitive decline and dementia. This does not mean these medications are dangerous for everyone, or that they cause dementia in any straightforward sense. The science is nuanced, the evidence varies in strength by drug class, and for many patients the therapeutic benefits of these medications far outweigh the cognitive risks.

What the research does suggest is that awareness matters. Patients who understand which medications have been studied in connection with cognitive outcomes are better positioned to have informed conversations with their physicians, to ensure their medication regimens are reviewed regularly, and to ask whether lower-risk alternatives might be appropriate for their specific situation.

This article reviews seven drug classes that have been examined in peer-reviewed research for potential associations with long-term cognitive decline. Each section notes the strength of the evidence, the proposed biological mechanisms where known, and importantly — the limitations and uncertainties that remain.

Important Medical Disclaimer: This article is for general educational and informational purposes only. It is not medical advice. Never stop, reduce, or change any prescribed medication without first consulting your doctor or pharmacist. Association in research studies does not equal causation. Many of the medications discussed have essential therapeutic benefits that outweigh risks for a large number of patients. Only your healthcare provider can evaluate whether any medication is appropriate for your individual situation.

How Researchers Study Drug-Cognitive Decline Links

Before examining specific medications, it is worth understanding how these associations are studied and why the evidence is often described as “mixed” or “inconsistent.”

The gold standard for establishing causation is a randomised controlled trial (RCT). But RCTs of long-term drug exposure and cognitive outcomes are difficult to conduct ethically: it would not be acceptable to randomly assign people to take a medication for years specifically to test whether it causes dementia. Instead, most of the evidence comes from observational studies, case-control studies, cohort studies, and meta-analyses that pool data from multiple studies.

These designs have important limitations. Confounding by indication is a central challenge: people who are prescribed sedatives, for example, may have higher dementia risk because they have anxiety or sleep disorders — not because of the medication itself. Protopathic bias is another concern: early, undiagnosed dementia may drive the prescription of a medication, making it appear that the drug preceded the disease when the opposite is true.

Researchers account for these biases in various ways, and the most rigorous studies control for known confounders, use active comparator designs, and apply latency windows to reduce reverse causation. Where studies use these more stringent methods, associations often weaken. This is the reason why the same drug class can appear strongly linked to dementia in one study and show no association in another.

Key principle: Association does not equal causation. When this article states that a medication has been ‘linked to’ cognitive decline, it means that observational research has found a statistical association. This is scientifically meaningful and worth understanding, but it does not mean the medication caused the outcome in any individual patient.

Medication 1: Anticholinergic Drugs

Anticholinergic medications block acetylcholine, a neurotransmitter that plays a central role in memory, learning, movement, and autonomic nervous system function. People with Alzheimer’s disease characteristically have depleted levels of acetylcholine in the brain — which is why cholinesterase inhibitor drugs are a primary treatment for the condition. The fact that anticholinergics work by blocking the same neurotransmitter that Alzheimer’s disease depletes makes the biological plausibility of a cognitive link particularly direct.

A 2021 meta-analysis published in ScienceDirect, pooling data from over 1.5 million subjects, found that anticholinergic drug use was associated with a 1.20-fold increased risk of all-cause dementia, with a dose-dependent relationship: higher cumulative exposure was associated with greater risk. A landmark JAMA Internal Medicine study examining 58,769 patients with dementia and 225,574 matched controls found significant increases in dementia risk associated with long-term use of anticholinergic antidepressants, antiparkinson drugs, antipsychotics, bladder antimuscarinics, and antiepileptic drugs.

Common drugs with strong anticholinergic properties include: bladder medications such as oxybutynin (Ditropan) and tolterodine (Detrol); older antihistamines (covered separately below); certain antidepressants including tricyclics (covered separately below); and some antipsychotics. The American Geriatrics Society’s Beers Criteria, the primary clinical guideline for medication safety in older adults, explicitly lists strong anticholinergics as medications to avoid or minimise in people aged 65 and older.

Important context: Anticholinergic burden is cumulative. A patient taking two or three medications with moderate anticholinergic properties may carry a higher overall anticholinergic load than someone on one strongly anticholinergic drug. Discussing total anticholinergic burden — not just individual medications — with a physician is particularly relevant for older patients.

Medication 2: Benzodiazepines

Benzodiazepines — which include diazepam (Valium), lorazepam (Ativan), and alprazolam (Xanax) — are prescribed for anxiety, panic disorder, insomnia, and muscle relaxation. They work by enhancing the action of GABA, an inhibitory neurotransmitter, producing calming and sedative effects.

Multiple large observational studies have found associations between long-term benzodiazepine use and increased dementia risk. Research published in the British Medical Journal (BMJ) identified a link between benzodiazepine use and Alzheimer’s risk. The 2020 FDA updated benzodiazepine labelling to include black box warnings about physical dependence, withdrawal risks, and cognitive impairment with extended use.

However, the evidence is not uniform. A large UK cohort study (Medical Research Council Cognitive Function and Ageing Study) that followed 8,216 participants over 10 years found that recurrent use of strong anticholinergics was associated with dementia, but neither benzodiazepines nor moderate anticholinergics reached statistical significance in their analysis after adjustment. The researchers concluded that the long-term prescribing of strong anticholinergics should be avoided in older people, while the benzodiazepine-dementia link remained less certain.

The clinical concern is not only about dementia risk. Benzodiazepines cause well-documented short-term cognitive effects including memory impairment, confusion, and disorientation, particularly in older adults whose slower drug metabolism means the substances remain active longer. The Beers Criteria recommends avoiding benzodiazepines in older adults regardless of the dementia question, due to risks of falls, fractures, motor vehicle accidents, and respiratory depression.

Medication 3: Non-Benzodiazepine Sleep Aids (Z-drugs)

The so-called Z-drugs — zolpidem (Ambien), eszopiclone (Lunesta), and zaleplon (Sonata) — were introduced as safer alternatives to benzodiazepines for insomnia. They act on similar brain receptors and have similar sedative effects, though with some differences in duration and side-effect profile.

Research has linked long-term Z-drug use to cognitive concerns. GoodRx’s medical review noted that older adults who take Ambien more frequently are more likely to develop dementia, and that the risk accumulates over time with total lifetime dose. A study published in Medicine found an increased risk of reversible dementia following zolpidem use in elderly populations.

The cognitive mechanism is related to their action on GABA receptors and their documented suppression of sleep architecture — including slow-wave sleep and REM sleep, which play critical roles in memory consolidation. Chronic disruption of normal sleep architecture may independently contribute to cognitive decline regardless of the specific sedative used.

For patients with chronic insomnia, Cognitive Behavioural Therapy for Insomnia (CBT-I) has been shown in multiple trials to be as effective as sleep medication over time, with no associated cognitive risk. Many sleep specialists now recommend CBT-I as first-line treatment, with medications reserved for short-term use.

Medication 4: First-Generation Antihistamines

First-generation antihistamines — most notably diphenhydramine, the active ingredient in Benadryl, Tylenol PM, ZzzQuil, and numerous other over-the-counter products — have significant anticholinergic properties. Because they are sold without a prescription, are inexpensive, and are widely used for allergies, insomnia, and cold symptoms, their potential cognitive effects receive less attention than those of prescription medications.

Diphenhydramine works by blocking acetylcholine as well as histamine receptors. The National Center for Health Research reviewed multiple studies finding that people who used anticholinergic drugs frequently for several years were more likely to develop dementia, with the risk persisting even when drug use started and stopped years before dementia symptoms appeared. The research showed that risk began accumulating when medications were taken daily for three or more years in some studies.

GoodRx’s medical review noted that while current evidence on diphenhydramine specifically is not entirely clear-cut, it has strong anticholinergic activity and the broader anticholinergic-dementia literature is concerning enough to warrant caution with regular long-term use, particularly in older adults.

Second-generation antihistamines such as loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra) have minimal anticholinergic activity and are generally preferred for older adults managing allergies, as they do not carry the same cognitive concern profile.

Practical note: Many people take diphenhydramine nightly as a sleep aid for months or years without realising it is an anticholinergic. Checking product ingredient labels and asking a pharmacist about anticholinergic burden in over-the-counter products is a step anyone can take independently, before any physician visit.

Medication 5: Tricyclic Antidepressants

Tricyclic antidepressants (TCAs) — including amitriptyline (Elavil), nortriptyline (Pamelor), imipramine, and doxepin — were the primary antidepressants before selective serotonin reuptake inhibitors (SSRIs) became standard in the 1980s and 1990s. They are still prescribed today for depression, neuropathic pain, migraines, and insomnia at low doses.

TCAs have among the highest anticholinergic burdens of any drug class in common clinical use. The JAMA Internal Medicine nested case-control study that examined anticholinergic drug exposure in nearly 285,000 patients found significant increases in dementia risk associated with long-term use of antidepressants with strong anticholinergic properties. TCAs figured prominently in this analysis given their high anticholinergic classification in the Beers Criteria and Anticholinergic Cognitive Burden scale.

For patients who use TCAs for depression, SSRIs and SNRIs (serotonin-norepinephrine reuptake inhibitors) generally carry substantially lower anticholinergic burden and are the preferred first-line agents in older adults. For patients using low-dose TCAs for pain or migraine, a conversation with a prescriber about whether alternatives with lower anticholinergic profiles are viable is reasonable to initiate.

Medication 6: Proton Pump Inhibitors (PPIs)

Proton pump inhibitors — including omeprazole (Prilosec), pantoprazole (Protonix), lansoprazole (Prevacid), and esomeprazole (Nexium) — are among the most widely prescribed and purchased medications in the world. They are used to treat gastroesophageal reflux disease (GERD), peptic ulcers, and as protective agents for patients taking NSAIDs.

The evidence connecting PPIs to cognitive decline is genuinely mixed and actively debated in the medical literature. Some large observational studies have found associations: a nationwide Danish population-based study published in Alzheimer’s & Dementia found an increased rate of dementia with cumulative PPI use, with larger associations in patients who developed dementia at younger ages. A Neurology study found that use of PPIs for more than 4.4 cumulative years was associated with a 33% higher risk of developing dementia.

However, equally rigorous studies have found no significant association. A prospective cohort study based on the ASPREE randomised trial, involving 18,934 older adults followed for a median of 4.5 years, found no significant difference in dementia rates between PPI users and non-users after full adjustment for confounders. A 2024 Mendelian randomisation study published in Scientific Reports — a design that more directly addresses causation — found no robust causal link between PPI use and increased dementia risk.

The proposed mechanisms include PPI-driven vitamin B12 deficiency (B12 is essential for neurological health), effects on amyloid-beta processing, and impacts on neuroinflammation. Approximately 40 to 70 percent of PPI prescriptions in hospitalised elderly patients are estimated to lack appropriate clinical indication, which makes the question of appropriate prescribing particularly relevant.

The bottom line on PPIs: The evidence is insufficient to recommend against PPIs for patients who genuinely need them. However, PPIs prescribed beyond their indicated duration, or without a clear ongoing clinical need, are a reasonable subject for a medication review conversation. The ACG and clinical pharmacists generally recommend periodic reassessment of whether long-term PPI use remains necessary.

Medication 7: Opioid Analgesics

Opioid analgesics — including oxycodone (OxyContin), hydrocodone (Vicodin), morphine, and tramadol — are prescribed for chronic and acute pain management. Their association with cognitive decline operates through several mechanisms that differ from the anticholinergic pathway.

Opioids act on mu-opioid receptors throughout the central nervous system, producing analgesia, sedation, and euphoria. Chronic opioid use has been associated with impairments in attention, memory, and processing speed, particularly at higher doses. A 2017 JAMA Internal Medicine study found an association between persistent pain — which itself is a risk factor for cognitive decline — and memory decline in longitudinal cohort data, making it difficult to separate the effects of the opioids from the pain they are treating.

Tramadol warrants specific mention because, in addition to its opioid activity, it has some serotonergic and noradrenergic effects and can interact with other medications in ways that compound cognitive risk. Research published in the Journal of Alzheimer’s Disease identified associations between sleep medication use and dementia risk that varied by race, suggesting that the cognitive consequences of opioid and sedative use may not be uniform across populations.

For patients managing chronic pain, multimodal pain strategies that reduce opioid dependence — including physical therapy, cognitive behavioural approaches to pain, and where appropriate non-opioid analgesics — are increasingly recommended. Patients who are concerned about long-term opioid use and cognitive health should discuss this with both their pain specialist and their primary care provider.

The Research Summary: Strength of Evidence

Medication Class	Proposed Mechanism	Strength of Evidence	Clinical Guideline Position
Anticholinergics (general)	Block acetylcholine, a neurotransmitter essential for memory	Strong (meta-analysis: 1.20x dementia risk; dose-dependent relationship)	Beers Criteria: Avoid/minimise in adults 65+
Benzodiazepines	GABA enhancement; chronic sedation effects on brain	Moderate (large observational studies show association; some rigorous studies show no effect)	Beers Criteria: Avoid in older adults; FDA black box warning added 2020
Z-drugs (sleep aids)	Similar to benzodiazepines; disrupts sleep architecture	Moderate (observational studies link long-term use to dementia risk)	Beers Criteria: Avoid in older adults; CBT-I preferred first-line
First-gen antihistamines (diphenhydramine)	High anticholinergic activity; blocks acetylcholine	Moderate (as part of anticholinergic class evidence)	Beers Criteria: Avoid in older adults; second-gen alternatives preferred
Tricyclic antidepressants	Very high anticholinergic burden	Strong (included in anticholinergic dementia evidence; Beers Criteria listed)	Beers Criteria: Avoid; SSRIs/SNRIs preferred in older adults
Proton pump inhibitors (PPIs)	Vitamin B12 depletion; amyloid processing effects; mechanism unclear	Mixed (some studies show association; rigorous studies show no effect)	Periodic reassessment of need recommended; do not stop without physician guidance
Opioid analgesics	Opioid receptor effects on cognition; pain itself is also a risk factor	Moderate (observational associations; confounding by pain condition)	Multimodal pain management preferred; minimise dose and duration where possible

What You Should Do: Talking to Your Doctor

Reading an article about medications and cognitive risk can feel alarming. It is worth reiterating: the most important thing you should not do is stop or reduce any prescribed medication on the basis of this or any other article. Abrupt discontinuation of benzodiazepines can cause dangerous withdrawal including seizures. Stopping antidepressants without medical supervision can cause withdrawal syndrome and psychiatric crisis. Discontinuing PPIs without guidance can cause acid rebound. Every change to a medication regimen requires medical supervision.
What this article can appropriately do is help you prepare for a more informed conversation with your physician or pharmacist. Here are specific questions that are reasonable to ask:

• "I’ve read that medications with anticholinergic properties may be associated with cognitive risk with long-term use. Can you review my current medications for anticholinergic burden?"
• "I’ve been taking [specific medication] for [X years]. Is this still the most appropriate option for my situation, or are there alternatives with a lower cognitive risk profile?"
• "I have been using [sleep aid / antihistamine] daily for [X months]. Is there a lower-risk alternative, or is CBT-I something I should consider for my insomnia?"
• "I’ve been on this PPI for more than two years. Is ongoing treatment still indicated, or is this something we should try to step down?"
• "I’m concerned about my overall medication burden as I get older. Can we schedule a comprehensive medication review?"

Annual medication reviews — sometimes called brown bag reviews, in which patients bring every medication they take to a single appointment — are a well-established geriatric care practice. Many pharmacists also offer medication therapy management (MTM) services specifically designed to assess drug interactions, inappropriate medications in older adults, and overall medication burden. These services are often covered by Medicare Part D.

Resource: The American Geriatrics Society’s Beers Criteria is a publicly available reference that identifies medications that may be inappropriate in adults aged 65 and older. Patients and caregivers can review it at AGSBeersCriteria.org or ask their pharmacist to check whether any current medications appear on the list.

Conclusion

The association between certain medication classes and long-term cognitive risk is a legitimate area of active scientific inquiry. The research reviewed in this article — drawn from JAMA, the BMJ, Nature, Alzheimer’s & Dementia, and other peer-reviewed sources — represents a genuine and growing body of evidence that clinicians and patients alike should take seriously.

That does not mean these medications are harmful for the majority of the patients who take them, or that the benefits of managing anxiety, reflux, insomnia, allergies, depression, or pain are outweighed by cognitive risks that are, in most studies, statistical associations rather than proven causal pathways. Medicine involves trade-offs, and the right answer for any individual is one that only a qualified healthcare provider can assess.

What this article does argue is that awareness changes conversations, and that conversations change outcomes. A patient who knows that long-term anticholinergic burden is a concern for older adults is better positioned to ask their physician whether their bladder medication, sleep aid, and cold medicine collectively represent a significant anticholinergic load. A patient who knows that CBT-I is at least as effective as sleep medication over the long term can ask their doctor about it. A patient who knows that their PPI prescription may no longer have a strong clinical indication can ask whether it is time to step down.

None of those conversations require alarm. They require information, which this article has attempted to provide accurately, with appropriate scientific caveats. The starting point for protecting your cognitive health is the same starting point for protecting your overall health: an informed, ongoing, collaborative relationship with the healthcare providers who know your complete medical picture.

Frequently Asked Questions

Does taking one of these medications mean I will develop dementia?

No. These medications are associated with elevated statistical risk in population-level studies, not individual destiny. Many people take these medications for years with no cognitive consequences. Risk factors are population-level concepts — they shift odds, they do not determine individual outcomes. If you have concerns about your cognitive risk, discuss your complete medication regimen with your physician.

Should I stop my medication after reading this?

No. Never stop, reduce, or alter any prescribed medication without consulting your physician or pharmacist. Abrupt discontinuation of benzodiazepines can cause life-threatening seizures. Stopping antidepressants without supervision can cause severe withdrawal. Changing any medication requires medical guidance tailored to your individual health history.

What are anticholinergics and why are they linked to dementia?

Anticholinergics are a class of drugs that block acetylcholine, a neurotransmitter essential for memory, learning, and other cognitive functions. People with Alzheimer’s disease have characteristically low acetylcholine levels, which is why medications that block it are of particular research interest. A 2021 meta-analysis of 1.5 million subjects found a 1.20-fold increased dementia risk associated with anticholinergic use, with a dose-dependent relationship.

What is the Beers Criteria?

The Beers Criteria is a list of medications that may be inappropriate in adults aged 65 and older, developed and regularly updated by the American Geriatrics Society. It is widely used by geriatricians, pharmacists, and primary care physicians when reviewing medications in older adults. It includes many anticholinergic drugs, benzodiazepines, Z-drugs, and other medications associated with risks that often outweigh benefits in elderly patients.

Are PPIs actually linked to dementia?

The evidence is mixed and actively debated. Some large observational studies have found associations between long-term PPI use and elevated dementia rates. Other rigorous studies, including a 2023 prospective cohort study of 18,934 older adults and a 2024 Mendelian randomisation study, found no significant causal link. Most experts recommend that PPIs continue to be used when clinically indicated, but that prescriptions are periodically reassessed for ongoing necessity.

Are second-generation antihistamines (Claritin, Zyrtec) safer for cognitive health?

Generally yes. Second-generation antihistamines such as loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra) have minimal anticholinergic activity and are generally preferred for older adults managing allergies. In contrast, first-generation antihistamines like diphenhydramine (Benadryl) have significant anticholinergic properties. The American Geriatrics Society specifically recommends avoiding diphenhydramine in older adults.

Can the cognitive effects of these medications be reversed if I stop them?

For some medications, particularly those with anticholinergic properties, the short-term cognitive effects (confusion, memory blurring, processing slowness) are generally reversible when the medication is stopped. Whether long-term use increases structural or permanent cognitive risk is what the dementia studies are examining, and here the evidence is less clear. Research from the National Center for Health Research noted that dementia risk from anticholinergic use appeared to persist even years after discontinuation in some studies, though this finding has been disputed on methodological grounds.

What is CBT-I and is it really as effective as sleep medications?

Cognitive Behavioural Therapy for Insomnia (CBT-I) is a structured programme that addresses the behavioural and cognitive factors maintaining chronic insomnia. Multiple randomised controlled trials have found it to be as effective as sleep medication in the short term and more durable over time. It is recommended as first-line treatment for chronic insomnia by the American College of Physicians and the American Academy of Sleep Medicine. It can be delivered by a therapist in person, through group programmes, or via digital platforms.

How do I ask my doctor about my medication’s cognitive risk without seeming difficult?

Most physicians welcome informed, specific questions. Frame it constructively: “I’ve been reading about anticholinergic burden in older adults and I want to make sure we’re managing that proactively. Can we review my current medications with that in mind?” You can also request a referral to a clinical pharmacist for a comprehensive medication review, which is often covered by Medicare Part D under Medication Therapy Management (MTM) programmes.

What does 'Medication Therapy Management' (MTM) mean?

MTM is a service provided by pharmacists, often covered by Medicare Part D, in which a licensed pharmacist conducts a comprehensive review of all of a patient’s medications, assesses for drug interactions, potentially inappropriate prescriptions, duplications, and other safety concerns. For older adults on multiple medications, an annual MTM review is an evidence-based practice that can identify high-risk medications before problems develop.