A large new study from the United Kingdom has raised fresh concerns about a drug often used to calm severe agitation in people with dementia.
The research found that the medication risperidone may increase the risk of stroke in dementia patients across all groups, including those who previously appeared to be at lower risk. The results suggest that doctors may need to rethink how and when the drug is prescribed.
Dementia is a condition that affects memory, thinking, and behavior. It is most common in older adults and includes diseases such as Alzheimer’s disease and vascular dementia. As the condition progresses, many patients develop difficult behavioral symptoms.
These can include agitation, aggression, restlessness, and emotional distress. Such symptoms can be extremely challenging for families and caregivers, especially in care homes or hospitals.
Doctors usually try non‑drug methods first to manage these symptoms. For example, caregivers may use calming routines, changes in environment, music therapy, or reassurance to reduce anxiety and agitation. However, these strategies do not always work. When symptoms become severe or dangerous, doctors may turn to medications.
One drug that is commonly used in these situations is risperidone. Risperidone belongs to a class of medicines known as antipsychotics. These drugs affect brain chemicals involved in mood, behavior, and perception. In dementia patients, risperidone can sometimes help reduce aggression or severe agitation that may put the patient or others at risk.
However, antipsychotic medications have long been associated with serious side effects in older adults. One of the most concerning risks is stroke, which occurs when blood flow to the brain is blocked or reduced. Because of this danger, the use of these medications in dementia has been debated for many years.
The new study adds important evidence to this debate. Researchers examined health data from more than 165,000 people diagnosed with dementia in the United Kingdom.
The data came from anonymized National Health Service medical records collected between 2004 and 2023. By studying such a large group of patients over many years, the researchers were able to look carefully at patterns of stroke risk.
The team compared dementia patients who were prescribed risperidone with similar patients who were not taking the drug. They wanted to see whether certain groups of patients might be more vulnerable than others. For example, researchers wondered whether people with existing heart disease or previous strokes might face greater risks.
What they discovered was surprising. The increased risk of stroke appeared across all patient groups, including people with no previous history of stroke or cardiovascular disease. This means the researchers could not identify a group of patients who could clearly be considered safe candidates for the drug.
Among dementia patients who had previously suffered a stroke, the annual stroke rate reached 22.2 cases per 1000 person‑years among those taking risperidone. In comparison, the rate was 17.7 among those who were not using the medication.
For patients who had never had a stroke before, the risk was lower but still noticeable. The stroke rate was 2.9 per 1000 person‑years among people taking risperidone compared with 2.2 among those not taking it. Although these numbers may appear small, they represent a meaningful increase when applied to large populations of older adults.
The researchers also noticed something unexpected. Stroke risk appeared to be somewhat higher among patients who used the drug for shorter periods of around 12 weeks. This finding may suggest that the early stages of treatment carry particular risks, although more research is needed to fully understand this pattern.
The study was led by Dr. Byron Creese of Brunel University of London and was published in the British Journal of Psychiatry. According to Dr. Creese, doctors had previously hoped that some groups of patients might be safer candidates for risperidone.
If that had been true, doctors could have avoided prescribing the drug to people with certain characteristics. However, the results suggest the increased stroke risk may apply broadly.
Despite these concerns, the drug continues to be used in dementia care because treatment options are limited. In the United Kingdom, risperidone is currently the only antipsychotic medication officially licensed for short‑term treatment of severe agitation in dementia.
National Health Service guidelines recommend that the drug should normally be used for no more than six weeks. In practice, however, some patients remain on the medication longer.
Another challenge is that there is no clear national guidance on how patients taking risperidone should be monitored for stroke risk. As a result, monitoring practices may vary across hospitals, care homes, and regions.
The findings highlight the difficult decisions faced by doctors and families caring for people with dementia. Severe agitation can cause enormous suffering for patients and caregivers. In some cases, medication may be necessary to prevent harm or distress. However, the potential side effects must be carefully weighed against the benefits.
From a scientific perspective, the study provides important real‑world evidence because it uses large‑scale healthcare records collected over nearly two decades. This type of data allows researchers to observe patterns that may not appear in smaller clinical trials.
However, observational studies cannot always prove that a drug directly causes a health problem. Other factors may also contribute to stroke risk in older adults with dementia.
Even so, the consistency of the findings across different patient groups strengthens the warning signal. The results suggest that doctors should approach risperidone prescriptions with caution and ensure that patients and families understand both the potential benefits and the risks.
In the future, researchers hope the findings will help improve guidelines and encourage the development of safer treatments for agitation in dementia. More research is needed to identify alternative therapies that can reduce distress without increasing the risk of serious complications.
Overall, the study reminds us that treating behavioral symptoms in dementia is a delicate balance. While medications like risperidone can sometimes provide relief from severe agitation, they also carry significant risks.
Careful monitoring, open communication between doctors and families, and continued research into safer treatments will be essential for improving dementia care.
If you care about dementia, please read studies that eating apples and tea could keep dementia at bay, and Olive oil: a daily dose for better brain health.
For more health information, please see recent studies what you eat together may affect your dementia risk, and time-restricted eating: a simple way to fight aging and cancer.
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