Most teens who've tried marijuana used it in more than one form, according to a new study, raising concerns about adolescent health amid a booming cannabis market. The study was published in JAMA Network Open.

Most teens who've tried marijuana have used the drug in more than one form, including cannabis products that are smoked, eaten or vaped. It raises concerns about adolescent health amid a booming cannabis market that touts sleekly packaged products claiming an array of health benefits.

Cannabis use in adolescence increases the risk of chronic use throughout adulthood, addiction and impaired cognitive development. In recent years, there's been a shift in teens' perception. Legalization and commercialization of cannabis are fostering the perception that this drug is not harmful.

Recreational marijuana 

On my drive to work, I pass an advertising billboard for marijuana delivery right to your house. Marijuana has gone mainstream. In a survey of 3,177 10th-graders from the Los Angeles area, Leventhal and his colleagues collected data via questionnaires at 10 Los Angeles area high schools from January to October 2015 — three years before California's 2018 legalization of recreational marijuana.

Of the 33.9% of students who reported ever using cannabis, smoking it was the most popular, followed by cannabis products that were edible or vaporized. Most 10th-graders (61.7%) who had ever used cannabis used multiple products to administer the drug.

Notably, 7.8% of cannabis "ever users" had never smoked pot, but instead ingested cannabis via edibles or vaping. A key question is whether a new pool of teens who've traditionally been at lower risk for smoking marijuana have been drawn to using the drug in these alternative non-smoked forms.

In other words, cannabis products such as bubblegum-flavored vaping liquid may appeal to teen users who would otherwise be turned off by the smell or harsh sensation of marijuana smoke. This study, supported by a grant from the National Institutes of Health (R01-DA033296), is part of an ongoing project looking at patterns of substance use and mental health over time.

Leventhal's previous survey studies have found digital media use is linked to behavioral and attention problems in kids, and that higher concentrations of nicotine in vaping liquid used by teens is associated with traditional cigarette use.