AsianScientist (Aug. 31, 2025) – As people live longer than ever, dementia is emerging as one of the world’s most pressing health challenges. Globally, millions of families already grapple with its devastating impact, and with no cure in sight, scientists are turning their focus toward identifying risk factors that can be managed or prevented.
Among the many suspects, painkillers may not be the first to come to mind. But new research suggests that regular opioid use, which is a common treatment for chronic non-cancer pain (CNCP), could significantly raise the risk of dementia, particularly vascular dementia.
CNCP refers to any persistent pain lasting more than three months that is not linked to cancer. It affects about 30 percent of the global population and is expected to grow steadily.
The findings, published in Alzheimer’s & Dementia, shed light on how long-term opioid use may affect the brain, offering new insights into the complex links between pain, medication, and cognitive decline.
The study revealed that people who regularly used opioids had a 20 percent higher risk of developing all-cause dementia compared to those taking other painkillers. The risk was even greater among strong opioid users, who faced more than a 70 percent increase of developing dementia. By contrast, individuals using non-opioid analgesics had dementia risks similar to non-users.
For this study, the researchers conducted a prospective cohort study involving 197,673 individuals with CNCP aged 37 to 73 from the UK Biobank – a large-scale biomedical research database and resource in the United Kingdom – with a mean follow-up of 13.8 years.
The study was led by Sha Feng, associate researcher from the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences, in collaboration with Jed A. Barash, Medical Director at the Massachusetts Veterans Home at Chelsea, and W. Andrew Kofke, Professor, the University of Pennsylvania.
“Our findings suggest that long-term opioid use may be neurotoxic and associated with an increased risk of dementia, which underscores the importance of weighing the cognitive risks of opioid use when managing CNCP,” the researchers stated in the study.
Since the mid-1990s, opioids have been widely prescribed to manage CNCP, but their inappropriate use, dependency issues, and misuse of high-potency opioids have raised public health concerns.
“Previous studies have suggested that opioid use may affect the endogenous opioid system and potentially impair the hippocampus and other central nervous system regions, increasing the risk of cognitive decline and dementia,” the paper stated.
Brain scans showed that regular use of strong opioids was linked to a shrinkage in overall brain size, including white matter and the hippocampus, an area vital for memory. Opioid users also performed worse on tests of fluid intelligence, though their prospective memory – the ability to remember to carry out future tasks, like taking medication or keeping appointments – was not significantly affected.
According to the study, these findings highlight the need to consider both the strength of the opioid and the length of use when assessing how these drugs may contribute to dementia and other health risks.
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Source: Shenzhen Institute of Advanced Technology ; Image: Shutterstock
The study can be found at: Regular use of opioids and dementia, cognitive measures, and neuroimaging outcomes among UK Biobank participants with chronic non-cancer pain
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