For the second year in a row, rapid rises in vaping among adolescents are the top story from the Monitoring the Future survey of drug use and attitudes among the country’s 8th, 10th, and 12th graders. What became evident in 2018 was that vaping devices, which have exploded in popularity over the past several years, are now exposing a new generation to nicotine. Those trends continued in 2019, but with the additional concern of a rapid rise in the vaping of marijuana, as well as increases in daily marijuana use in 10th graders.
More than one fifth of high school seniors (20.8 %) reported having vaped marijuana in the past year, as did nearly that same proportion of 10th graders (19.4 %). From 2018 to 2019, the percentage of seniors vaping marijuana in the past month increased from 7.5 percent to 14 percent—the second largest one-year increase in any drug use that has ever been recorded in the 45-year history of the MTF survey. (The first largest increase was nicotine vaping from 2017 to 2018 reported last year.) Among 10th graders, past-month use was 12.6 percent.
Overall, marijuana use has held relatively steady over the past several years despite wider availability and diminished perception of the drug’s harms by this age group (and by the U.S. population more generally). But the increases in vaping of THC, the active ingredient in marijuana, are alarming for a number of reasons. For one thing, we don’t yet know if THC’s effects differ when vaped versus when smoked in a traditional fashion or whether the amount of THC that youth are being exposed to differs with these methods.
Also, the students took the survey in January of this year, which was before the alarming news this summer about serious lung illness and a number of deaths (48, as of this writing) in people using vaping devices. Most of the illnesses occurred in people who had vaped THC. It is not known whether the cause may have been contamination in certain black market vape fluids, or some other factor. The CDC has named vitamin E acetate as a chemical of concern in vape fluids, but it is too soon to rule out other chemicals or device attributes that may also contribute to the illnesses.
At this point, we know very little about the health and safety effects of administering THC at high concentrations, and this applies not only to vaping but also to smoking of concentrated THC products and new edible products and beverages coming on the market in states that have legalized marijuana for adult use. Research is urgently needed to answer these questions. However, marijuana is federally classified as a Schedule 1 substance. Scientists face administrative hurdles when studying Schedule 1 substances, and currently there are no provisions allowing federally funded researchers to study marijuana products coming from the black market or even from dispensaries in states where they are permitted to operate. Resolving these research barriers is an urgent priority.
Daily marijuana use has remained steady among 12th graders, at 6.4 percent, but this number conceals a very significant gender difference. Eight percent of male seniors report using marijuana daily, whereas 4.6 percent of females do. This suggests that a disproportionate percentage of male students may not be performing to their potential because of daily impairment by that drug.
Increased daily marijuana use by younger teens is another worrying trend in this year’s survey results. This year, 4.8 percent of 10th graders reported daily marijuana use, as did 1.3 percent of 8th graders. The brain is very much a work in progress throughout adolescence, and this is especially true at younger ages, so there is increased risk of long-term harms as well as addiction when 8th and 10th graders use any substance, including marijuana.
The continued increase in nicotine vaping by adolescents is also concerning. A quarter of 12th graders reported past-month vaping of nicotine, as did nearly 20 percent of 10th graders and nearly 10 percent of 8th graders. It is not yet leading to increased cigarette use in this age group—one of the many bright spots in this year’s survey is continued downward trends in smoking—but many public health experts worry that vaping will lead to nicotine addiction in many users of these devices.
The number of 12th graders who vape because they say they are “hooked” more than doubled between 2018 and 2019, from 3.6 percent to 8.1 percent. Addiction to nicotine could lead some users to switch to conventional cigarettes—a trajectory already found in some studies. Another noteworthy statistic in the MTF findings is that teens’ second most cited reason for vaping was liking the taste—a strong argument in favor of limiting the flavorings in vape products as a way of limiting these products’ tremendous appeal.
Apart from the real concerns linked to marijuana and nicotine vaping, the general picture painted by the MTF survey continues to be largely encouraging, however. Most illicit drug use continues to decline or hold steady at low levels. Cocaine and methamphetamine use are as low as they have ever been despite increases seen in adults. Nonmedical use of prescription opioids, which had raised worries several years ago in this survey, is also way down. And thankfully, the crisis of heroin use that continues unabated in U.S. adults also does not seem to be affecting high school students—heroin use continues to be very rare among teens surveyed, with past year use among high-school seniors at 0.4 percent. The fact that MTF is a survey of students in school is important to remember, however. It necessarily does not sample from those who have dropped out of school, and thus misses capturing a segment of the youth population for whom drug use is likely more prevalent.
See all the findings of the 2019 MTF survey, our press release, fact sheet and two infographics on vaping and other drug categories. For more information on the increases in marijuana vaping and what they mean, read the research letter published today in JAMA.
The MTF survey is a valuable indicator of substance use trends in the segment of the population most vulnerable to the short- and long-term effects of drug exposure. It is also the most “real-time” survey of drug use patterns: Every January, 42,531 students in 396 public and private schools across the nation take an hour or so to complete the MTF questionnaire—increasingly, on tablets rather than on paper—and the results are tabulated and analyzed by the end of that same year. It gives the NIDA-funded researchers at the University of Michigan, currently led by Richard A. Miech, an unprecedented ability to track substance use in real time.