More and more teenagers are turning to marijuana. A new study shows heavy marijuana use among U.S. teens is up 80-percent since 2008, with nine-percent admitting to smoking pot at least 20 times in the past month.

Twenty-seven-percent of teens admit to using marijuana at least once in the past month, up 42-percent from 2008.

Researchers say the last time marijuana use was this high among teens was more than a decade ago in 1998. Meanwhile, teen cigarette smoking appears to be on the decline. Only 22-percent of teens admit to smoking cigarettes in the previous month. That’s down 19-percent from last year.

Teen ecstasy use, on the other hand, is up 50-percent since 2008, with nine-percent of teens saying they’ve taken “E” in the past year. Teen alcohol abuse appears to be holding steady, with 56-percent admitting to drinking alcohol in the past year. The survey was conducted by The Partnership at Drugfree.org and MetLife Foundation.