A major new study warns that gabapentin — a drug millions use for chronic back pain — may come with a hidden cognitive risk. Researchers examined medical records from 68 U.S. health systems, comparing 26,414 adults taking gabapentin with similar patients who did not. Those who had six or more prescriptions were 29% more likely to be diagnosed with dementia and 85% more likely to develop mild cognitive impairment (MCI) within 10 years.

Younger adults saw the most dramatic increases. People aged 35–49 taking gabapentin had more than double the risk of dementia, and their risk of MCI more than tripled. Adults 50–64 faced similar risks, while those 18–34 showed none.

Researchers reported in Regional Anesthesia & Pain Medicine: “Our results support the need for close monitoring of adult patients prescribed gabapentin to assess for potential cognitive decline.”

The risk rose with heavier use. People with 12 or more prescriptions were 40% more likely to develop dementia and 65% more likely to develop MCI, even after adjusting for health issues, age, and other medications.

The study does not prove that gabapentin directly causes dementia. It was observational, and researchers could not measure dosage or duration precisely. Still, the findings match other concerns about side effects such as dizziness, fatigue, dry mouth, swelling, and earlier links to breathing problems.

Gabapentin became widely used as a perceived safer alternative to opioids and is often prescribed long-term for back pain. Experts say the new data highlight the importance of regular cognitive check-ins, discussing risks with your doctor, and avoiding unnecessary long-term use.

As the study concludes: “Our findings indicate an association between gabapentin prescription and dementia or cognitive impairment within 10 years.”