United States marijuana legalization and opioid mortality epidemic during 2010–2020 and pandemic implications

The hypothesis that marijuana availability reduces opioid mortality merits more complete testing, especially in a country with the world’s highest opioid death rate and 2nd highest cannabis-use-disorder prevalence.

The United States opioid mortality rate was compared in states and District of Columbia that had implemented marijuana legalization with states that had not, by applying joinpoint methodology to Centers for Disease Control and Prevention data. Variables included race/ethnicity and fentanyl-type opioids (fentanyls).

After the same rates during 2010–2012, the opioid mortality rate increased more rapidly in marijuana-legalizing than non-legalizing jurisdictions (2010–2020 annual pairwise comparison p = 0.003 for all opioids and p = 0.0004 for fentanyls). During the past decade, all four major race/ethnicities in the U.S. had evidence for a statistically-significant greater increase in opioid mortality rates in legalizing than non-legalizing jurisdictions. Among legalizing jurisdictions, the greatest mortality rate increase for all opioids was in non-Hispanic blacks (27%/year, p = 0.0001) and for fentanyls in Hispanics (45%/year, p = 0.0000008). The greatest annual opioid mortality increase occurred in 2020, the first year of the COVID-19 pandemic, with non-Hispanic blacks having the greatest increase in legalizing vs. non-legalizing opioid-death-rate difference, from 32% higher in legalizing jurisdictions in 2019 to more than double in 2020.

Instead of supporting the marijuana protection hypothesis, ecologic associations at the national level suggest that marijuana legalization has contributed to the U.S.’s opioid epidemic in all major races/ethnicities, and especially in blacks. If so, the increased use of marijuana during the 2020–2022 pandemic may thereby worsen the country’s opioid crisis.


To read the full study by IASIC Board Member Kevin Flinn, click here: https://www.sciencedirect.com/science/article/abs/pii/S0027968422000529?dgcid=coauthor

For more information on the International Academy on the Science and Impact of Cannabis, and to join, please visit www.IASIC1.org.

Visit the IASIC Library here (https://iasic1.org/library/). The IASIC Library is intended as a user-friendly reference of the published medical literature.

Like this article?

Share on Facebook
Share on Twitter
Share on Linkdin
Share on Pinterest

Related Posts

IASIC Speaker Series Presents  Cannabis and Mental Health

The International Academy on the Science and Impact of Cannabis (IASIC) is excited to present the IASIC Speaker Series. Presented free of charge, this ongoing educational seminar series will focus on the science, data and peer-reviewed research surrounding marijuana and will be led by international medical experts. This non-partisan and non-political series is continually developed,

Placebo Effect a Major Driver of Pain Reduction in Cannabis Trials

A strong placebo response may be largely responsible for the significant pain reduction observed in clinical trials of cannabis-based therapies, results of a new meta-analysis suggest. Investigators found that while the effect size of cannabinoids on pain intensity was significant, the placebo effect was about the same. “The data from the present meta-analysis, including 1459

Trends in Cannabis Use Disorder Diagnoses in the U.S. Veterans Health Administration, 2005–2019

Since 2005, diagnoses of cannabis use disorder have increased substantially among VHA patients, as they have in the general population and other patient populations. Possible explanations warranting investigation include decreasing perception of risk, changing laws, increasing cannabis potency, stressors related to growing socioeconomic inequality, and use of cannabis to self-treat pain. Clinicians and the public

Cannabis legalization and cannabis-involved pregnancy hospitalizations in Colorado

The primary objective of this study was to evaluate the association between presence of recreational cannabis dispensaries and prevalence of cannabis-involved pregnancy hospitalizations in Colorado. This was a retrospective cohort study of pregnancy-related hospitalizations co-coded with cannabis diagnosis codes in the Colorado Hospital Association from January 1, 2011, through December 31, 2018 (recreational cannabis began

Scroll to Top