States that legalized the use of medical marijuana have lower opioid overdose mortality rates, according to new research in JAMA Internal Medicine. Lead author Marcus A. Bachhuber, M.D., of the Center for Health Equity Research and Promotion, Philadelphia Veterans Affairs Medical Center, and his research team analyzed state medical marijuana laws and opioid overdose deaths using death certificate data from 1999-2010. They found that states that had medical marijuana laws before 2010 had a 24.8 percent lower annual opioid overdose on average compared to states that outlawed medical marijuana. Study abstract