In states where marijuana is legalized, underage use is *dropping*.

CNN reports on a JAMA Pediatrics study that found an interesting correlation between decriminalizing cannabis and teenagers’ use of the plant. Recreational use among teens actually goes down in states with legal access to the drug:

Laws that legalized recreational marijuana were associated with an 8% drop in the number of high schoolers who said they used marijuana in the last 30 days, and a 9% drop in the number who said they’d used at least 10 times in the last 30 days….

The paper involved analyzing data, from 1993 to 2017, on about 1.4 million high school students in the United States from the US Centers for Disease Control and Prevention’s annual national Youth Risk Behavior Surveys.
The researchers took a close look at self-reported marijuana use in the surveys among the students as well as survey responses in areas where medical or recreational marijuana was legalized.

The researchers examined the responses before and after the marijuana laws were implemented.

The data showed that marijuana use among high schoolers was not statistically associated with medical marijuana laws, but there was a link with recreational marijuana laws.

When it comes to the new paper, “I think the big question is why,” [Stanford pediatrics professor Bonnie] Halpern-Felsher said. “Why are they seeing in this national dataset decreases — pretty significant decreases — when other studies are finding no difference?”

The researchers wrote in the paper that one possible explanation could be that in states where recreational marijuana is legal, “it is more difficult for teenagers to obtain marijuana as drug dealers are replaced by licensed dispensaries that require proof of age.”

You can read the study here.