Marijuana use among teens has not increased in states that have passed medical or recreational marijuana laws in the past 25 years, a new study finds – in fact, legalization may be making it more difficult for teens to obtain pot.

Using data from national and state Youth Risk Behavior Surveys from 1993 to 2017, researchers from Montana State University, University of Oregon, University of Colorado–Denver and San Diego State University examined states that had legalized marijuana for recreational or medical use and the likelihood of marijuana use in the past 30 days among high school students.

Read more at US News.