In the midst of an opioid crisis, some medical practitioners and researchers say they think that greater use of marijuana for pain relief could result in fewer people using the highly addictive prescription painkillers that led to the epidemic.

A 2016 study by researchers at Johns Hopkins Bloomberg School of Public Health found that states with medical marijuana laws had 25 percent fewer opioid overdose deaths than states that do not have medical marijuana laws. And another study published in Health Affairs last year found that prescriptions for opioid painkillers such as OxyContin, Vicodin and Percocet paid for by Medicare dropped substantially in states that adopted medical marijuana laws.

In December, the New York Health Department said it would start allowing some patients with certain types of chronic pain to use marijuana as long as they have tried other therapies. The state’s original medical marijuana law, along with those in Connecticut, Illinois, New Hampshire and New Jersey, did not include chronic pain as an allowable condition for marijuana use, in part over concerns that such a broad category of symptoms could result in widespread and potentially inappropriate use of the controversial medicine.

Advocates for greater use of medical marijuana argue that including chronic pain as an allowable condition could result in even further reductions in dangerous opioid use.