New Study Finds Decreased Rates of Teen Pot Use in States With Legal Cannabis

A new study has found that the rate of cannabis use by teens has gone down in states that have legalized recreational marijuana. Results of the research were published online on Monday by JAMA Pediatrics.

To conduct the study, researchers analyzed survey data on marijuana use by 1.4 million teenagers from 1993 to 2017. During that time period, 27 states and Washington, D.C. legalized medical marijuana, while seven states legalized the recreational use of cannabis.

The study found that states with laws legalizing the recreational use of cannabis saw an 8 percent drop in the rate of teens who reported using marijuana during the previous 30 days and a decrease of 9 percent in the rate of frequent cannabis use. Frequent use was defined as the use of marijuana at least 10 times during the previous 30 days.

Mark Anderson, an associate professor in agricultural economics at Montana State University in Bozeman and lead author of the study, noted that states that had only legalized medical marijuana did not see an associated drop in teen use.

“Just to be clear we found no effect on teen use following legalization for medical purposes, but evidence of a possible reduction in use following legalization for recreational purposes,” said Anderson.

The researcher theorized in an email to Reuters that the drop in teen use in states with legal recreational cannabis could be caused by a decline in the number of people selling marijuana on the black market.

“It may actually be more difficult for teens to obtain marijuana as drug dealers are replaced by licensed dispensaries that require proof of age,” wrote Anderson. “Selling to minors becomes a relatively more risky proposition after the passage of these laws.”

Helping Teens Make Informed Decisions

Rebekah Levine Coley, a professor of developmental and educational psychology at Boston College who wasn’t involved in the research, said that legalization may lead to “increased parental supervision or discussions between parents and adolescents regarding the dangers of marijuana use in reaction to legalization and the resultant increases in political and news attention and perceived availability.”

Dr. Ellen Rome, head of the Center for Adolescent Medicine at Cleveland Clinic Children’s in Ohio, who also did not participate in the research, said that for conversations between parents and teens to be effective, two-way communication is key.

“Have frank discussions with your teen, where you ask first what they believe about teens and marijuana use before and after legalization,” Rome said. “Then share your own beliefs, and encourage dialogue – and ask what they believe will help prevent youth from using illegally.”

Another academic not involved in the study, Bonnie Halpern-Felsher, a professor of pediatrics at Stanford University’s Division of Adolescent Medicine, said that discussions with parents and teens should be backed up with scientific information on the potential risks of cannabis.

“The other question is, are youth getting the message about the fact that using marijuana during adolescence is more harmful because of their brain development?” Halpern-Felsher said. “Given the legalization, we need more education around marijuana or cannabis use for youth and we don’t really have a lot of education.”