Doctoral researcher Marta Arbizu Gómez presents the clinical keys to drug-induced cognitive impairment, a common but underdiagnosed adverse effect that can drastically alter patients’ memory and attention.
Drug-induced cognitive impairment (DICI) is a common but highly underdiagnosed adverse effect that can mimic dementia or mild cognitive impairment in clinical practice. In this article, we analyze in detail which medications affect memory, attention, and other executive functions, ranging from central nervous system drugs to common non-neurological treatments. Discover the physiological mechanisms behind these often reversible alterations, and why integrating a comprehensive medication review is key for neurorehabilitation professionals.
Can medications affect our cognition?
In clinical practice, when a patient presents with problems with memory, attention, or language, it is common to think of neurodegenerative diseases, psychiatric disorders, or aging. However, there is a factor that is often overlooked: the medications themselves.
Drug-induced cognitive impairment (DICI) is a well-documented complication that can occur with multiple treatments, both neurological and non-neurological. Despite this, it continues to be frequently underdiagnosed, which can lead to significant clinical errors.
This phenomenon does not only affect older adults or occur in severe cases of dementia. It may manifest subtly, affect specific cognitive domains, and appear in young adults and even children.
What is drug-induced cognitive impairment (DICI)?
Cognitive impairment induced by drugs is defined as an alteration in cognitive functions directly caused by a medication. These alterations may affect different domains:
- Memory (forgetfulness, difficulty remembering recent information);
- attention (distractibility, difficulty concentrating);
- processing speed (mental slowness);
- language (word-finding difficulties);
- and executive functions (planning, decision-making).
One of the main problems is that these symptoms can mimic neurological diseases, such as mild cognitive impairment or dementia, making identification difficult.
Prevalence of drug-induced cognitive impairment
Available data suggest that the impact of drug-induced cognitive impairment is clinically significant:
- Drugs may be implicated in up to 30% of cases of delirium in hospitalized older adults.
- It is estimated that between 2.7% and 10% of dementias may be related to medications.
- Polypharmacy exponentially increases the risk of cognitive impairment.
In addition, population aging and increased medication use suggest that this problem will become increasingly relevant.
Which medications can cause cognitive impairment?
One of the study’s most important conclusions is that many types of drugs can affect cognition, including those that do not act directly on the brain.
Central nervous system (CNS) drugs
- Antiepileptic drugs;
- antidepressants;
- antipsychotics;
- and benzodiazepines.
These usually affect memory, attention, and cognitive speed.
Drugs with sedative or anticholinergic effects
- First-generation antihistamines;
- medications for urinary incontinence;
- and some antidepressants.
They are particularly associated with:
- Memory problems;
- confusion;
- and delirium.
Other associated non-neurological drugs
- Opioids;
- corticosteroids;
- proton pump inhibitors (omeprazole);
- statins;
- antihypertensives;
- and chemotherapy.
This finding is key: cognition can be affected by a wide range of treatments, not only neurological ones.
Below is a more detailed summary of how different drug classes can affect specific cognitive processes:
| Drug class | Type of cognitive impairment | Specific details |
|---|---|---|
| Antiepileptic drugs | Attention, executive functions, processing speed, learning | Cognitive slowness, difficulties with verbal learning and memory; effects more pronounced with polytherapy |
| Topiramate / zonisamide | Memory and language | Difficulties with naming, verbal fluency, and memory; effect particularly relevant with topiramate |
| Tricyclic antidepressants | Memory and learning, delirium | Anticholinergic effect → impaired memory, confusion; increased risk of delirium |
| SSRIs / SNRIs | Low risk, mild impact | Possible mild cognitive slowing; less impact than tricyclics; generally safe |
| Antiparkinsonian drugs (dopaminergic agonists) | Confusion, delirium | Cognitive fluctuations, altered alertness, and impaired cognitive control |
| MAO inhibitors / amantadine | Delirium | Acute mental status changes, especially in vulnerable patients |
| Antipsychotics | Delirium, attention, executive functions | Reduced processing speed, verbal memory, and executive functions; increased risk in older adults |
| Lithium | Cognitive slowness, memory, attention | Reduced alertness, sustained attention, and psychomotor speed; impact on memory |
| Benzodiazepines and Z-drugs | Amnesia, attention, speed | Anterograde amnesia, reduced vigilance, psychomotor slowing; cumulative risk |
| Opioids | Attention, memory, speed | Sedation, cognitive slowing, impaired attention and memory; dose-dependent effect |
| Antihistamines (1st generation) | Memory, attention | Anticholinergic effect → cognitive impairment, especially in older adults |
| Corticosteroids | Memory, mental status | Changes in mood and memory, with possible confusion |
| PPIs (omeprazole, etc.) | Long-term cognitive risk | Association with cognitive impairment (mechanism not completely clear) |
| Antihypertensives | Attention, mental status | Possible impact from hypotension → reduced cerebral perfusion |
Mechanisms: why drug-induced cognitive impairment occurs
The mechanisms are multiple and depend on the drug, but some of the most relevant include:
- Acetylcholine blockade → affects memory;
- sedation → reduces attention and cognitive speed;
- dopaminergic alterations → affect executive functions;
- inflammation and oxidative stress;
- hippocampal damage;
- and reduced cerebral blood flow.
In many cases, these effects are reversible when treatment is adjusted or discontinued, reinforcing the importance of identifying them correctly.
Challenges in diagnosing drug-induced cognitive impairment
Despite its relevance, drug-induced cognitive impairment remains poorly recognized in clinical practice. One of the main reasons is that:
- Only 6.5% of clinical trials assess the cognitive safety of drugs;
- screening tools with limited sensitivity are used;
- and mild effects often go unnoticed.
This means that many cases go undetected and may be mistakenly interpreted as primary cognitive impairment.
What are the implications of drug-induced cognitive impairment for clinical practice?
Recognizing drug-induced cognitive impairment has direct implications:
More accurate diagnosis
Considering medications as a potential cause helps prevent misdiagnoses of dementia or mild cognitive impairment.
Reversible interventions
Unlike many neurodegenerative diseases, drug-induced cognitive impairment may improve when treatment is adjusted.
Prevention
Reducing polypharmacy and choosing drugs with less cognitive impact may lower the risk.
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How does this relate to NeuronUP?
At NeuronUP, the focus is on cognitive assessment and rehabilitation. In this context, drug-induced cognitive impairment is particularly relevant because it:
- Can alter cognitive performance reversibly, affecting the interpretation of results;
- helps identify cases in which pharmacological intervention is key;
- reinforces the need for a comprehensive patient assessment, combining clinical, pharmacological, and cognitive data.
In addition, cognitive monitoring through digital tools can help detect treatment-related changes and track their progression.
Conclusion on medication and cognitive impairment
Drug-induced cognitive impairment is a common, complex, and often underdiagnosed phenomenon. Its impact ranges from mild symptoms to conditions that may mimic dementia, with significant consequences if it is not recognized in time.
In a context of increasing medication use and population aging, integrating cognitive assessment into clinical practice—together with a careful medication review—is essential to improve diagnosis and patients’ quality of life.
References
- Reimers A, Odin P, Ljung H. Drug-Induced Cognitive Impairment. Drug Safety. 2025;48(4):339–361. https://doi.org/10.1007/s40264-024-01506-5
Frequently asked questions about the exposome and brain health
1. What is drug-induced cognitive impairment (DICI)?
Drug-induced cognitive impairment, or DICI, is defined as an alteration in cognitive functions directly caused by taking a medication. Far from being limited to older adults or severe cases of dementia, it may occur in young adults and even children, often manifesting subtly. These alterations may affect key cognitive domains, including memory (forgetting recent information), attention (distractibility), processing speed (mental slowness), language (difficulty finding words), and executive functions (problems with planning and decision-making).
2. Is drug-induced cognitive impairment reversible?
In many cases, yes. Unlike many primary neurodegenerative diseases, the cognitive changes caused by DICI may improve or completely resolve when the dose is adjusted or the medication is discontinued. This underscores the importance of considering medication as a potential cause so that early, reversible interventions can be implemented.
3. Which common medications can cause memory or attention problems?
Cognition may be affected by a wide variety of treatments, not only neurological medications. Common examples include central nervous system drugs (antiepileptic drugs, antidepressants, antipsychotics, and benzodiazepines). Medications with sedative or anticholinergic effects are also important, including first-generation antihistamines and medications for incontinence, as are commonly used drugs such as opioids, corticosteroids, antihypertensives, and proton pump inhibitors (omeprazole).
4. How can drug-induced cognitive impairment be distinguished from dementia?
This is an important clinical challenge because DICI symptoms can mimic neurological diseases such as dementia or mild cognitive impairment. Differentiation requires a comprehensive assessment combining the clinical history, a thorough review of polypharmacy, and cognitive testing. Digital monitoring tools, such as NeuronUP, can help track changes following treatment adjustments.
5. Why is drug-induced cognitive impairment underdiagnosed?
Despite its frequency—it may be implicated in up to 30% of cases of delirium in hospitalized older adults—it often goes unnoticed for several reasons: mild effects are commonly overlooked, screening tools with limited sensitivity are used, and only 6.5% of clinical trials adequately assess the cognitive safety of medications. In addition, memory problems are often mistakenly attributed simply to aging.
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