In 2014, the Journal of the American Medical Association (JAMA) published a study that conducted a time-series analysis examining medical cannabis laws and state-level death certificated data in the U.S. from 1999-2010, covering all 50 states with the goal of analyzing age-adjusted opioid analgesic overdose death rates per 100,000 population in each state.
The study found a link between states that had implemented medical cannabis laws and slower increases in opioid overdose deaths, creating further support for the legalization of marijuana. In fact, to date this study has been cited by over 350 scientific articles.
However, a new study from the National Academy of Sciences of the United States of America was recently published, finding that this is no longer the case. This study was conducted using the same methods as the original JAMA study, but with extra data extending through 2017, a total of seven years of additional information to pull from. In that time, 32 states enacted medical cannabis laws, and eight states enacted recreational cannabis laws.
The original JAMA study’s findings no longer held up across the longer period. Using the full 1999-2017 dataset, the new study found that states that enacted a medical cannabis law experienced a 22.7% increase in opioid overdose deaths. However, the study does not conclude that marijuana laws increase opioid overdose deaths, claiming that if a relationship exists between the two, it cannot be rigorously discerned with aggregate data and that more research should continue.
Currently, the clinical research is still inconsistent. A study from the Public Library of Science (PLOS) found a strong correlation between enrollment in medical marijuana programs and reduced opioid use for patients with chronic pain, while another study from the Journal of Bone and Joint Surgery found self-reported marijuana use during injury recovery was associated with an increased amount and duration of opioid use.
Furthermore, JAMA also published a new study on the association of medical marijuana laws with nonmedical prescription opioid use and prescription opioid use disorder. Looking at data from 627,000 individuals from the 2004-2014 National Survey on Drug Use and Health, little evidence was found for an association between medical marijuana law enactment and nonmedical prescription opioid use or prescription opioid use disorder among prescription opioid users.
As clinical research goes on, Healthesystems will continue to monitor ongoing developments.