A popular pain medication taken by millions of Americans for chronic back issues may carry a concerning, largely unnoticed risk. A major new study suggests that long-term use of gabapentin could significantly increase the likelihood of developing dementia or other forms of cognitive decline.

Researchers from Case Western Reserve University and several partner institutions reviewed medical records from 68 U.S. health systems. Their analysis included more than 26,000 adults who had been prescribed gabapentin for persistent low-back pain, compared with a matched group dealing with the same condition but not taking the drug.

The findings were unsettling. Adults who received six or more prescriptions for gabapentin were 29% more likely to be diagnosed with dementia within 10 years. Their chances of developing mild cognitive impairment (MCI) were even higher — an 85% increase.

Perhaps most alarming: the heightened risks did not spare younger patients. Adults who should be decades away from cognitive decline saw some of the most dramatic increases. Those ages 35 to 49 who used gabapentin had more than double the risk of developing dementia and more than triple the risk of MCI. Adults between 50 and 64 saw similarly elevated risks. The only group unaffected was those between 18 and 34.

The results, published in Regional Anesthesia & Pain Medicine, came with a clear warning from the researchers: patients taking gabapentin should be closely monitored for any signs of cognitive changes.

Gabapentin has known side effects—dizziness, fatigue, swelling, dry mouth—and earlier research has raised concerns about breathing issues. But this new study revealed something deeper: the more prescriptions a patient had, the greater their long-term cognitive risk. Those with 12 or more prescriptions were 40% more likely to develop dementia and 65% more likely to develop MCI. This pattern held steady even after researchers adjusted for other health issues, demographics, and additional medications.

Still, the team emphasized that the study was observational. It demonstrates an association, not direct proof that gabapentin causes dementia. They also weren’t able to track precise dosages or how long each patient took the drug. Even so, the scale of the dataset and the consistency of the results point toward a meaningful concern.

Gabapentin has grown dramatically in popularity since its approval in the early 1990s, originally intended for epilepsy. Today, it is widely prescribed for nerve pain, chronic back pain, post-shingles pain, and restless legs syndrome. Physicians often reach for it as a safer alternative to opioids, especially for long-term management of difficult pain conditions.

Researchers noted that many people who rely on gabapentin for back pain already struggle with mobility — itself a known dementia risk factor. But in this study, users were matched with non-users facing similar limitations, suggesting that mobility alone doesn’t explain the cognitive decline.

For patients, the message isn’t to panic. It’s to stay informed.

Experts recommend regular cognitive check-ins for anyone taking gabapentin long-term, especially middle-aged and older adults. They also advise speaking with doctors about possible alternatives or adjustments to dosage and avoiding prolonged use when it isn’t necessary.

Gabapentin remains a safer option than many pain medications, but like any drug, it comes with complexities worth understanding. As the researchers put it, the association between gabapentin use and later cognitive impairment “should not be ignored,” particularly given how widely the medication is prescribed.

For millions relying on it to get through the day, this new evidence raises important questions — and underscores the importance of paying attention to both pain relief and long-term brain health.