Cannabis Use Among U.S. High School Seniors Shifted Toward Vaping and Edibles From 2015 to 2018
Among U.S. high school seniors who used cannabis, smoking became less common between 2015 and 2018 while vaping and eating cannabis became more prevalent. The findings come from a 2020 research letter published in JAMA Pediatrics that analyzed nationally representative Monitoring the Future survey data.
The study examined 9,097 responses from 12th-grade students collected between 2015 and 2018. Of those students, 2,989—32.9 percent—reported using marijuana during the previous year. Complete information about consumption methods and other characteristics was available for 2,412 of those respondents.
Vaping and edible use increased among cannabis users
Among past-year cannabis users, the share who reported smoking marijuana fell from 94.7 percent in 2015 to 89.3 percent in 2018. Over the same period, edible use rose from 32.0 percent to 39.5 percent, while vaping increased from 26.4 percent to 34.1 percent.
In 2018, 27.4 percent of all surveyed 12th graders reported smoking marijuana during the previous year. Eating marijuana was reported by 12.1 percent, and vaping by 10.5 percent. Some students also reported other methods, including dabbing and drinking cannabis products.
The study measured changes in the method of consumption, not an overall increase in cannabis use. In other words, the results suggest that how adolescents used cannabis was changing even though the prevalence of marijuana use itself remained relatively stable during the period studied.
Most students who vaped or ate cannabis also smoked it
Noncombustible products generally supplemented rather than replaced smoked marijuana. Only 12.3 percent of students who vaped cannabis and 8.1 percent of those who used edibles said they had not smoked marijuana during the previous year.
Frequent use was also more common among students who reported vaping or eating cannabis. Daily or near-daily use—defined in the study as use on at least 20 occasions during the previous 30 days—was reported by 28.5 percent of vapers and 26.7 percent of edible users, compared with 17.6 percent of smokers.
These figures do not show that vaping or edibles cause heavier use. They do indicate that asking adolescents only whether they smoke marijuana could miss a substantial portion of their cannabis use.
Patterns differed across demographic groups
After the researchers adjusted for other characteristics, boys had higher odds than girls of reporting cannabis vaping or edible use. White students had higher odds than Hispanic students of smoking marijuana and higher odds than Black students of vaping or eating it. White students also had lower odds of edible use than Asian students.
Students with at least one college-educated parent—a measure the researchers used as a proxy for socioeconomic status—had higher odds of vaping than students whose parents had less education. Compared with students in rural schools, those in urban schools had higher odds of vaping and using edibles, while students in suburban schools had higher odds of edible use.
These are statistical associations, not explanations for why students chose particular products. The survey cannot establish that location, sex, race, or socioeconomic status directly caused differences in consumption patterns.
Important limitations
The analysis was limited to students in 12th grade and did not include adolescents who were absent from school or had dropped out. It was also based on self-reported survey responses.
The researchers noted that the wording and response options for vaping changed in 2018. The survey shifted from asking about marijuana use “in a vaporizer” to asking about “vaping,” and it added dabbing as a separate option. Those changes may have affected how some students answered and make comparisons across years less certain.
More broadly, the study was observational. It identified trends and associations but could not determine whether product availability, marketing, perceived risks, social influences, or other factors drove the shift toward vaping and edibles.
Why the findings matter
Different cannabis products can carry different risks. According to the Centers for Disease Control and Prevention’s guidance on cannabis and teens, adolescent cannabis use may affect attention, memory, learning, coordination, and the developing brain. Edibles can also take longer to produce effects, potentially increasing the risk of consuming too much.
Vaping presents additional concerns because the contents of some products—particularly those obtained from informal or illicit sources—may be unknown. During the 2019 outbreak of e-cigarette- or vaping-associated lung injury, CDC investigations found a strong association between the illness and THC-containing vaping products, especially products containing vitamin E acetate. The agency’s laboratory investigation of lung-injury cases documented vitamin E acetate in lung-fluid samples from affected patients, while noting that other substances could also have contributed.
The 2015–2018 findings support a broader approach to screening and prevention. Health professionals, parents, and educators should ask adolescents about smoking, vaping, edibles, dabbing, and other forms of cannabis use rather than treating “smoking marijuana” as the only relevant measure. Continued surveillance is also needed to track how youth consumption patterns change as cannabis products and markets evolve.
