A woman rolls a joint while wearing marijuana plant inspired socks and leggings while attending the Colorado 420 Rally at Civic Center Park in Denver, Co on April 20, 2014. (Helen H. Richardson, The Denver Post)

No increase in teen marijuana use in 2014, national survey finds

Teen use of marijuana has not increased in the past four years nationwide, even as the country has undergone a transformation in marijuana’s legality and availability, according to the results of a new survey released Tuesday.

Instead, the annual Monitoring the Future survey found that various measures of teen marijuana use across the country decreased slightly in 2014. When all age groups in the study are combined, teens reporting lifetime use of marijuana dropped in 2014 by 1.4 percent, and teens reporting monthly use of marijuana dropped by 1.2 percent. Two other measurements of use also declined.

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Marijuana use by middle and high school students — especially frequent use — is now as low as it has been in the past four to six years. It remains, though, generally at or above the 10-year average.

“We have not seen increases in the use, which is something we were afraid would happen,” Dr. Nora Volkow, the director of the National Institute on Drug Abuse, said in a conference call with reporters on Tuesday.

Overall, the survey found that about 30 percent of teens questioned said they had used marijuana in their lifetimes, while about 14 percent said they had used marijuana in the previous month.

The survey did not provide Colorado-specific data.

The Monitoring the Future study has been conducted every year for the past 40 years. It currently measures marijuana use for three age groups — eighth graders, 10th graders and 12th graders — and across four different measurements — lifetime use, yearly use, monthly use and daily use.

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The slight drops in marijuana use fit with a year that saw bigger drops in prescription drug abuse, alcohol use and cigarette smoking. Lloyd Johnston, the study’s architect at the University of Michigan, said the overall results were “music to the ears of the nation’s parents.”

But Volkow was less pleased with the study’s findings on marijuana use, which she said “continues to be at very high levels.” She noted that teens’ perception of marijuana’s harmfulness declined again in the survey, something health officials have suggested could be a precursor to greater use.

She also noted that the survey found a shift in how marijuana is consumed in medical marijuana states. Teens in such states were about one-and-a-half times more likely to consume marijuana in edible products than teens in states without medical marijuana laws, according to the survey. Volkow said more study is needed to determine the “bioavailability” of pot in the body after consuming edibles and how that might affect the brain differently.

The national survey fits with a Colorado survey released earlier this year that also found slight drops in marijuana use, even as perceptions of marijuana’s harms also decreased.

John Ingold: 303-954-1068, jingold@denverpost.com or twitter.com/johningold

This story was first published on DenverPost.com