Medical cannabis laws are associated with significantly lower state-level opioid overdose mortality rates. Further investigation is required to determine how medical cannabis laws may interact with policies aimed at preventing opioid analgesic overdose.
Medical cannabis laws and opioid analgesic overdose mortality in the United States, 1999-2010. Bachhuber MA, Saloner B, Cunningham CO, Barry CL. JAMA Intern Med. 2014 Oct;174(10):1668-73.