This was reported back in August 2014:
TIME: Aug. 25, 2014 by
@acsifferlin
Opioids for chronic pain, like OxyContin, Percocet and Vicodin, are
meant to suppress pain. Recent data shows that not only are
prescriptions for these drugs up, but rates of overdose and death are increasing as well. New research published Monday in the journal JAMA Internal Medicine
shows that states with medical marijuana laws have rates of anticipated
opioid-related deaths 25% lower than states that don’t allow it.
Read the full story:
http://time.com/3175582/states-with-medical-marijuana-laws-have-fewer-opioid-overdose-deaths/