Johns Hopkins Study Suggests Teen Marijuana Usage Has Gone Down

BALTIMORE (WJZ) – A recent Johns Hopkins School of Public Health study showed that marijuana usage among American high school students is significantly lower than it was 15 years ago, despite its legalization in many states where it's used for medicinal purposes.

Researchers at the Johns Hopkins Bloomberg School of Public Health say that marijuana use is significantly greater than the use of other illegal drugs, with 40 percent of teens in 2013 saying they had smoked marijuana at least once. That number was down from 47 percent in 1999 but up from 37 percent in 2009. By contrast, just 3 percent had tried methamphetamines in 2013 as compared to 9 percent in 1999.

"People have been very quick to say that marijuana use is going up and up and up in this country, particularly now that marijuana has become more normalized," says study leader Renee M. Johnson, assistant professor in the Department of Mental Health at the Bloomberg School.

"What we are seeing is that since 1999 -- three years after medical marijuana was first approved -- the rates of marijuana use have actually fallen. But we will be watching those states where recreational marijuana use has been legalized to see if that leads to increased use among teens."

The findings, published online this month in the journal Drug and Alcohol Dependence, also suggest that the gender gap in marijuana use -- where boys outnumbered girls as users of the drug -- is shrinking, with males and females now using it at similar rates.