Law enforcement encourages teen marijuana use study shows

This article was originally published on the Marijuana Patients Organization site on November 9, 2013.

Since the United States began considering medical marijuana legislation, claims have frequently been made that the laws “send the wrong message” to adolescents, causing their marijuana use to increase. Now, more than 17 years after the passage of the nation’s first effective state medical marijuana law, California, a considerable body of data has found that those fears were not warranted.

Twenty states and Washington, D.C. now have effective medical marijuana laws. In 15 of the states, government surveys have produced before-and-after data on teens’ marijuana use. In 10 states, the data shows overall decreases, most of which were within confidence intervals. No state with a statistically significant change saw an increase in teens’ marijuana use.

Several other researchers and health experts have examined the data over the past few years and have also found the data to be reassuring. Dr. Seth Ammerman published an article in the Winter 2011 edition of California Pediatrician, finding, “Medical Marijuana for adults in all states that have approved medical marijuana has not led to an increase in recreational marijuana use in adolescent populations.”1

Here is a review of the most comprehensive data on teens’ current (past 30 day) marijuana use in each of medical marijuana states. In all but four of the states, the data included is for all high schoolers. In those states, data is not available for all high schoolers, so this instead includes data from the oldest grade with before-and-after data: 11th grade in California and Oregon and 12th in Washington. The only “before- and-after” data for Colorado was a small survey of 12-17 year olds that does not control for age.

Teen marijuana usage before medical marijuana laws compared to teen use after implementation of law.

California (1996)
25.9% (’95/’96)
24.2% (’09/’10)
decrease (not statistically significant) Source: California Student Survey

Alaska (1998)
28.7% (1995)
21.2% (2011)
decrease. Source: The CDC’s Youth Risk Behavior Surveillance System (YRBSS)

Oregon (1998)
21% (1998)
20.6% (2011)
decrease. Source: Oregon Public Schools Drug Use Survey & Oregon Healthy Teens

Washington (1998)
28.7% (1998)
26.7% (2012)
decrease (changed Washington State Survey survey) of Adolescent Health Behaviors & Healthy

Maine (1999)
30.4% (1997)
21.2% (2011)
decrease The CDC’s YRBSS

Hawaii (2000)
24.7% (1999)
21.9% (2011)
decrease (within The CDC’s YRBSS confidence interval)

Nevada (2000)
25.9% (1999)
20% (2009) decrease (within The CDC’s YRBSS confidence interval)

Colorado
10.3% (1999)
10.2% (2010)
increase (within National Survey on Drug (2000) ’11) confidence interval) Use & Health

Vermont
28.2% (2003)
24.4% (2011)
decrease (within The CDC’s YRBSS (2004) confidence interval)

Montana
23.1% (2003)
21.2% (2011)
decrease (within The CDC’s YRBSS (2004) confidence interval)

Rhode Island
25% (2005)
26.3% (2011)
increase (within The CDC’s YRBSS (2006) confidence interval)

New Mexico
26.2% (2005)
27.6% (2011) increase (within The CDC’s YRBSS (2007) confidence interval)

Michigan (2009)
18.3% (2007)
18.6% (2011)
(within The CDC’s YRBSS (2008) confidence interval)  Marijuana use among Oakland County’s teens is higher than the nationwide average (and all MI counties), according to data provided by the Alliance of Coalitions for Healthy Communities. Twenty-seven percent of Oakland County high school seniors reported using marijuana over the 30-day period before they took the alliance’s most recent survey. Oakland county has been the most vocal about restricting access, and the county’s teen marijuana statistics increased the State average significantly.

New Jersey
20.3% (2009)
21.1% (2011)
increase (within The CDC’s YRBSS (2010) confidence interval)

Arizona (2009)
23.7% (2009)
22.9% (2011) decrease (within The CDC’s YRBSS (2010) confidence interval)

Delaware
No data available, law is too new. (2011)

Connecticut
No data available, law is too new. (2012)

Massachusetts
No data available, law is too new. (2012)

New Hampshire (2013)
No “after” data available, law is too new.

Illinois (2013)
No “after” data available, law is too new.

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1 Ammerman, Seth, M.D. “Medical Marijuana: Update for the Pediatrician,” California Pediatrician, Vo. 27, No. 1 (Winter 2011): 11-13 available at http://www.aap-­-ca.org/news/caPed/California%20Pediatrician%20-­-%20Winter%202011.pdf