Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Aug;103(8):1500-6.
doi: 10.2105/AJPH.2012.301117. Epub 2013 Jun 13.

Effects of state medical marijuana laws on adolescent marijuana use

Sarah D Lynne-Landsman  1 , Melvin D Livingston, Alexander C Wagenaar
Affiliations

Effects of state medical marijuana laws on adolescent marijuana use

Sarah D Lynne-Landsman et al. Am J Public Health. 2013 Aug.

Abstract

Objectives: Medical marijuana laws (MMLs) have been suggested as a possible cause of increases in marijuana use among adolescents in the United States. We evaluated the effects of MMLs on adolescent marijuana use from 2003 through 2011.

Methods: We used data from the Youth Risk Behavior Survey and a difference-in-differences design to evaluate the effects of passage of state MMLs on adolescent marijuana use. The states examined (Montana, Rhode Island, Michigan, and Delaware) had passed MMLs at different times over a period of 8 years, ensuring that contemporaneous history was not a design confound.

Results: In 40 planned comparisons of adolescents exposed and not exposed to MMLs across states and over time, only 2 significant effects were found, an outcome expected according to chance alone. Further examination of the (nonsignificant) estimates revealed no discernible pattern suggesting an effect on either self-reported prevalence or frequency of marijuana use.

Conclusions: Our results suggest that, in the states assessed here, MMLs have not measurably affected adolescent marijuana use in the first few years after their enactment. Longer-term results, after MMLs are more fully implemented, might be different.

PubMed Disclaimer

Figures

FIGURE 1—
FIGURE 1—
Planned comparisons for difference-in-differences analyses of states with medical marijuana laws: United States, 2003–2009. Note. DE = Delaware; MI = Michigan; MT = Montana; RI = Rhode Island.
FIGURE 2—
FIGURE 2—
Marijuana use prevalence in (a) Montana, (b) Rhode Island, (c) Michigan, and (d) Delaware: Youth Risk Behavior Survey, 2003–2009. Note. Vertical solid lines indicate years in which medical marijuana laws were enacted.
See this image and copyright information in PMC

References

    1. Pacula RL, Chriqui JF, Reichmann DA, Terry-McElrath YM. State medical marijuana laws: understanding the laws and their limitations. J Public Health Policy. 2002;23(4):413–439. - PubMed
    1. US Department of Justice. Drug Enforcement Administration. Title 21 United States Code (USC) Controlled Substances Act. Available at: http://www.deadiversion.usdoj.gov/21cfr/21usc/index.html. Accessed February 11, 2013.
    1. Johnston LD, O’Malley PM, Bachman JG, Schulenberg JE. Monitoring the Future National Results on Adolescent Drug Use: Overview of Key Findings, 2010. Ann Arbor, MI: Institute for Social Research, University of Michigan; 2011.
    1. Gorman DM, Huber JC., Jr Do medical cannabis laws encourage cannabis use? Int J Drug Policy. 2007;18(3):160–167. - PubMed
    1. Khatapoush S, Hallfors D. “Sending the wrong message”: did medical marijuana legalization in California change attitudes about and use of marijuana? J Drug Issues. 2004;34(4):751–770.

Publication types

LinkOut - more resources