A recent study has found an 8 percent decline in the number of high schoolers who have used cannabis within the last 30 days, and a 9 percent drop among teenagers who have used cannabis 10 times in the last month, suggesting that cannabis use among youth may decline following recreational legalization.
The JAMA Pediatrics-published study from researchers in Montana, Oregon, Colorado, and California, focused on data from high school surveys in states with legalized medical and recreational cannabis use.
“…There was no evidence that the legalization of medical marijuana encourages marijuana use among youth. Moreover, the estimates … showed that marijuana use among youth may actually decline after legalization for recreational purposes.” — “Association of Marijuana Laws With Teen Marijuana Use,” JAMA Pediatrics, July 8
The researchers note that the decline is consistent with previous research that concluded: “it is more difficult for teenagers to obtain marijuana as drug dealers are replaced by licensed dispensaries that require proof of age.”
Mark Anderson, an associate professor at Montana State University and the first author of the paper, suggested to CNN that the team’s research is “the most credible to date in the literature” because the study was “based more on policy variation than prior work.”
The study analyzed data from high school surveys from 1993 to 2017 – about 1.4 million student surveys – from the Centers for Disease Control and Prevention’s annual national Youth Risk Behavior Surveys.
“Because many recreational marijuana laws have been passed so recently, we do observe limited post-treatment data for some of these states,” Anderson said in a CNN interview. “In a few years, it would make sense to update our estimates as more data become available.”
A study published in the American Journal of Health last week found a contrasting result: youth who only use cannabis reached its highest levels ever in 2017 – 6.3 percent – after being just 0.6 percent in 1991. That study also found an increase in dual use of alcohol and marijuana from 3.6 percent in 1991 to 7.6 percent in 2017, while dual use of alcohol and cigarettes declined from 11.8 percent to 1.7 percent.