Opioid use is not associated with an increased risk of Alzheimer’s disease, according to a recent study from the University of Eastern Finland. Researchers did not find any risk for long-term use nor for higher cumulative doses, a university press release reports.

According to researchers, a previous study from the US reported an association between high cumulative doses of opioids and an increased risk of dementia, but the Finnish study did not confirm this finding.

The research was part of the nationwide register-based MEDALZ study of approximately 350,000 patients, including 70,718 patients diagnosed with Alzheimer’s disease in Finland during 2005-2011.

While no dementia risk was found, researchers report several adverse effects related to opioid use, such as drowsiness, reduced alertness, addiction, or tolerance to pain-relieving effects. As a result, opioid use should be restricted to the most severe pain conditions only, the researchers report.