KDRVStudy: Opioid Use Lower In States With Medical MarijuanaKDRVA new study published in the Journal of American Medical Association finds states with easy-to-access medical marijuana, like Oregon, are seeing less opioid usage than others. Posted: Apr. 4, 2018 6:36 PM. Updated: Apr. 4, 2018 6:42 PM. Posted By: Emma ...