“We had predicted based on the changes in legalization, culture in the U.S. as well as decreasing perceptions among teenagers that marijuana was harmful that [accessibility and use] would go up,” Volkow said. “But it hasn’t gone up.”

Legalization advocates said the findings supported their position: “Every time a state considers rolling back marijuana prohibition, opponents predict it will result in more teen use,” said Mason Tvert of the Marijuana Policy Project in a statement. “Yet the data seems to tell a very different story. There has been a sea change in state marijuana laws over the past six years and teen usage rates have remained stable and even gone down in some cases.”

Taken as a whole, this year's Monitoring the Future report is another indicator that the current crop of American teenagers is one of the most well-behaved cohorts in decades.

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