Marijuana is now more popular among teens than tobacco or e-cigarettes

Teen drug use is largely on the decline, with one notable exception — marijuana.

Nearly 23 percent of high school seniors reported using marijuana in the past month, according to new data from the National Institute on Drug Abuse and the National Institutes of Health, which collected responses as part of an annual survey of teen drug use known as “Monitoring the Future.”

The survey polled eighth, 10th, and 12th grade students from across the country about their drug and alcohol consumption.

“Now we have more teenagers smoking marijuana than cigarettes,” Dr. Nora Volkow, the director of the National Institute on Drug Abuse, said in an interview.

“If you ask if they smoke, they think you mean marijuana,” she said.

Read more: Nora Volkow: Leading a revolution against drug addiction

There was a significant tumble in tobacco use among teens, in keeping with the decline seen over the past two decades. In 1991 — the first year the survey collected data on cigarette smoking — nearly 11 percent of high school seniors smoked at least a half a pack a day. In 2015, just 1.8 percent of high school seniors did.

And the rate of teens reporting they’ve been drunk in the past year has also hit an all-time low. About 37 percent of 12th grade students reported being intoxicated in the past year, compared with a peak rate of 53 percent in 2001.

Volkow attributed those declines to efforts to curb alcohol and tobacco use among teens.

“There have been very, very strong prevention campaigns targeted toward teenagers,” she said, adding that those prevention campaigns “may have had an unintended consequence in reducing use of other drugs.”

One of the most surprising statistics? The relatively stable rate of heroin use. Just 0.3 percent of high school seniors reported having injected heroin in the past year, the same rate seen in 2014. Volkow said those figures caught her eye, given that heroin use among adults in the US is on the rise.

“Teenagers perceive heroin as very harmful,” she explained.

Just under 5 percent of high school seniors reported having used opioid pain relievers for non-medical reasons, down from a peak rate of 9.4 percent in 2004. The rate of non-medical use of the ADHD drug Adderall — which 6 percent of high school seniors reported using in the past year — has remained fairly stable.

Marijuana remains a major hurdle in tackling illicit drug use among adolescents, Volkow said. She expressed concern that new marijuana laws have the potential to make it easier for teenagers to try weed — opening the door for them to use other illicit substances, too.

“This is a stage of great vulnerability for drug consumption,” she said. “These policy changes influence teenagers, even though we may not be seeing it.”