Study: Legal Medical Marijuana Doesn't Increase Youth Use

No increase found among teenage pot smokers in states following the legalization of medical marijuana

A new study conducted over the course of 24 years has found that there is no correlation between legalized medical marijuana and teenage marijuana use. Credit: Barbara Peacock/Getty

As the debate over medical marijuana looms in places like New York, a new study conducted over the course of 24 years has found that there is no correlation between legalizing medical marijuana and the increased use of the drug among teenagers. In data collected from surveys of over 1 million teens culled from 48 states, the study showed that there was no increase in pot smoking among adolescents after a state had legalized medical marijuana, the New York Times reports.

The study directly contrasts opponents of medical marijuana who claim that the legalization of the drug in any capacity sparks an uptick in youth pot smoking, since the perception of the drug is more relaxed after its decriminalization. "We have a war going on over marijuana, and I think both sides have been guilty at times of spinning the data," Dr. Kevin Hill, an assistant professor of psychiatry at Harvard, told the Times. "It's nice to have a scientifically rigorous study to guide policy."

While the study did reveal that marijuana use among teens in states with medical marijuana was more prevalent in states without medical marijuana – 16 percent to 13 percent, respectively – that too had little to do with decriminalization. In Illinois, where medical marijuana was legalized in 2013, the study showed that "no hint of an increase at all after the laws were passed," said Columbia University's Deborah Hasin, who led the research team.

The study also discovered that the overall percentage of marijuana use among youths is on the rise, but alcohol, nicotine and opioid use all declined over the study period. The study, which was published in The Lancet Psychiatry, did not specify the impact the legalization of non-medical marijuana in states like Colorado and Oregon has on teenage pot smoking.