Debunking claims about medical marijuana

marijuana
Credit: CC0 Public Domain

In 1996, California became the first US state to legalise marijuana use for medical purposes. Medical marijuana is now legal in 29 states. Opponents of medical marijuana argue that such laws increase recreational marijuana use among adolescents, while advocates contend that medical marijuana helps to address the US opioid crisis by reducing overdose deaths.

Two papers published today in the scientific journal Addiction look at the current evidence of the effects of laws and conclude that there is little support for either claim.

The first claim, that legalizing medical marijuana increases recreational use among adolescents, is addressed by a new meta-analysis that pooled the results of eleven separate studies of data from four large-scale US surveys dating back as far as 1991. Results of the meta-analysis indicate that no significant changes (increases or decreases) occurred in adolescent recreational use following enactment of . Far fewer studies examined the effects of medical marijuana laws among adults, although existing evidence suggests that adult recreational use may increase after medical marijuana laws are passed

Senior author Professor Deborah Hasin says, "Although we found no significant effect on adolescent marijuana use, we may find that the situation changes as commercialized markets for medical marijuana develop and expand, and as states legalize use. However, for now, there appears to be no basis for the argument that legalising medical marijuana increases teens' use of the drug."

The second claim, that legalising medical marijuana reduces opioid overdose deaths by offering a less risky method of pain management, is addressed in an editorial co-authored by several members of Addiction's editorial board. Here, the evidence is clear but weak, being rooted in ecological studies whose results have not been confirmed through more rigorous methods. Although those studies show a correlation over time between the passage of medical laws and opioid overdose rates, they do not provide any evidence that the laws caused the reduction in deaths. In fact, several recent studies have shown that who use cannabis do not use lower doses of opioids. There are more plausible reasons for the reduction in opioid deaths that ought to be investigated.


Explore further

Study questions link between medical marijuana and fewer opioid deaths

More information: Sarvet AL, Wall MM, Fink DS, Greene E, Le A, Boustead AE, Pacula RL, Keyes KM, Cerda M, Galea S, and Hasin DS (2018) Medical marijuana laws and adolescent marijuana use in the United States: A systematic review and meta-analysis. Addiction, DOI: 10.1111/add.14136

Hall W, West R, Marsden J, Humphreys K, Neale J, and Petry N (2018) It is premature to expand access to medicinal cannabis in hopes of solving the US opioid crisis. Addiction, DOI: 10.1111/add.14139

Journal information: Addiction

Provided by Society for the Study of Addiction
Citation: Debunking claims about medical marijuana (2018, February 22) retrieved 22 October 2019 from https://medicalxpress.com/news/2018-02-debunking-medical-marijuana.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
32 shares

Feedback to editors

User comments

Feb 23, 2018
This comment has been removed by a moderator.

Feb 23, 2018
This comment has been removed by a moderator.

Feb 23, 2018
Wayne Hall tends to be as anti-cannabis as science will allow.

In regard to opioids, the use of cannabis in managing pain is one of its most important.

4 out of 5 heroin users begin with prescription opioids [Lankenau et al. 2012]. The reason is simple, heroin and opioids such as hydrocodone (Vicodin), oxycodone (OxyContin, Percocet), are very similar drugs. When prescriptions run out, people turn to far less expensive, more available, more potent heroin from the street to support their habit.

Legal medical cannabis has been shown to significantly reduce deaths from prescription opioid painkillers by reducing opioid use:

"States with medical cannabis laws had a 24.8% lower mean annual opioid overdose mortality rate compared with states without medical cannabis laws." [Bachhuber et al. 2014]

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more