Hospitals in states where medical marijuana is legal treat far fewer opioid users, a new study has found.

The report in Drug and Alcohol Dependence found that, on average, hospitalization rates for opioid painkiller dependence and abuse plummeted 23 percent in states after medical marijuana was legalized, while hospitalization rates for opioid overdoses dropped 13 percent.

The report also found no uptick in cannabis-related hospitalizations in these states.

"Instead, medical marijuana laws may have reduced hospitalizations related to opioid pain relievers," said study author Yuyan Shi of the University of California, San Diego.

"This study and a few others provided some evidence regarding the potential positive benefits of legalizing marijuana to reduce opioid use and abuse, but they are still preliminary.”

It’s been reported that the country’s opioid epidemic – triggered by a quadrupling since 1999 in sales of prescription painkillers like Oxycontin and Vicodin – kills 91 Americans a day.

Shi’s study – which involved analyzing hospitalization records from 1997 through 2014 for 27 states – was the fifth to show a decline in opioid use or deaths in states with medical marijuana legislation.

h/t NBC News