In news that should serve as a wake-up call for legislators across the U.S., cannabis legalization in Colorado resulted in a “reversal” of opioid overdose deaths in the state. This was the key takeaway from a study published in the American Journal of Public Health.

“After Colorado’s legalization of recreational cannabis sale and use, opioid-related deaths decreased more than 6 percent in the following two years,” write authors Melvin D. Livingston, Tracey E. Barnett, Chris Delcher and Alexander C. Wagenaar.

While the authors press that these results are preliminary, this is one of the first reports to look at the effect recreational legalization (rather than medical) has had on America’s opioid crisis.

Marijuana’s potential as a safe and effective alternative to powerful painkillers – or even as an exit drug for opioid addicts – has been gaining more and more attention in recent months.

The authors of this study looked at the rate of monthly opiate overdose deaths in Colorado before and after the launch of the state’s recreational cannabis market in 2014. After controlling for both medical marijuana and a change in Colorado’s prescription drug monitoring program, the researchers found that opioid deaths fell by 6.5 percent in the two years after the state implemented its recreational cannabis laws.

The authors say legislators would be wise to stay abreast of these numbers in coming years to see whether the pattern they identified continues. They’re also planning to see whether their findings hold true in other states with recreational legalization, like Washington and Oregon.

h/t The Washington Post