Teens & Pot Laws

Medical marijuana legalization may not necessarily increase usage rates in teens

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) When marijuana was made medically legal in certain states, researchers found teenager’s desire or ability to gain access was not impacted. It appears dispensaries aren’t weed candy stores for minors.

A recent study conducted by a team of economists crunched the numbers in states where medical marijuana had been legalized to see if rates of teenage marijuana use increased.

The economists may have found numbers to suggest usage rates actually dropped slightly.

"Talk to your kids about drug abuse."

Daniel I. Rees, PhD, professor of economics at the University of Colorado at Denver, Benjamin Hansen, PhD, assistant professor of economics at the University of Oregon, and Mark Anderson, PhD, assistant professor of economics at Montana State University, looked at data from the Youth Risky Behavior Survey (YRBS), which provided information on high school students from 1993-2009 in the 13 states where medical marijuana was made legal during that time span.

They also looked at data from the National Longitudinal Survey of Youth (NLSY), 1997, and Treatment Episode Data Set (TEDS).

The authors said, “Federal officials contend that the legalization of medical marijuana encourages teenagers to use marijuana. . . Our results are not consistent with the hypothesis that legalization leads to increased use of marijuana by teenagers.”

Alaska, California, Colorado, Hawaii, Maine, Michigan, Montana, Nevada, New Mexico, Oregon, Rhode Island, Vermont and Washington all legalized medical marijuana between 1996-2008. Since then four more states and the District of Columbia have joined them.

The annual report, by the University of Michigan Institute for Social Research, “Monitoring the Future: National Results on Adolescent Drug Use”, from 2011, showed that 10th and 11th graders have been increasing their use of marijuana over the last three years.

The authors said that the report's claim of the increase in high school students using marijuana gave federal officials ammunition to target medical marijuana dispensaries.

The authors argued that the presence of medical marijuana does not increase the chances of a high school kid using marijuana.

They also refer to a study where 49 percent of treatment-seeking teenagers admit that they illegally obtained marijuana from local growers who had surplus marijuana after legally selling to the dispensaries.

In the study, the authors calculated changes in the frequency of marijuana usage and compared it to the legalization of medical marijuana.

Depending on what controls were used in the calculation the overall use of marijuana in medical marijuana states. Overall they found, “[A] 1.7 percentage point decrease in the probability of marijuana use in the last 30 days, and a 0.8 percentage point decrease in the probability of frequent use.”

According to the authors, adults are more sensitive to the legality of a drug and their usage than teenagers. 

This study was published in May by the Institute for the Study of Labor (IZA) in Bonn, Germany. The IZA is a private, non-profit independent research institute and the paper has been made available on their non-peer-reviewed website. No financial information was given and no conflicts of interest were found.

Reviewed by: 
Review Date: 
June 28, 2012
Last Updated:
December 4, 2012