National Surveillance of Youth Substance Use: Keeping Up With Changing Times

Thirty years ago, youth smoking was in a grim place. In 1991, more than one in four US high school students smoked cigarettes, and the situation was worsening, reaching 36% smoking prevalence in 1997.¹ Likewise, adolescent alcohol use remained perniciously steady at about 50% prevalence throughout the 1990s.¹ Since then, a host of hard-fought wins for tobacco control, including prevention and cessation programs, excise taxes, marketing restrictions, and social norms change, have borne remarkable success in driving down youth smoking. In 2019, cigarette smoking by high school students stood at just 6% nationally¹ and was low enough in some regions to have policymakers aiming for a tobacco endgame. Youth alcohol use, too, has declined to its lowest level in more than 40 years of national surveillance.² Despite these successes, there is much work to be done. Substance use remains higher in certain geographic regions and among vulnerable groups, including racial/ethnic minorities, sexual and gender minority youths, and the socioeconomically disadvantaged.³ Novel nicotine products and liberalizing marijuana regulations pose new challenges for youth substance use prevention. This AJPH Assessing Impact feature reexamines one recent look at changing youth substance use patterns over the past 30 years.

In the 2019 article “Trends in Single, Dual, and Poly Use of Alcohol, Cigarettes, and Marijuana Among US High-School Students: 1991–2017,”⁴ public health successes with youth cigarette and alcohol use are only two thirds of the story. The author, Hongying Dai, contrasts the overall declines in youth cigarette and alcohol use with rising levels of youth marijuana consumption. In 1991, no US states allowed medical or recreational marijuana sales; today, more than 70% of Americans reside in a state that does. Accepting social attitudes toward marijuana have grown, and so too has marijuana use, in all age groups.⁵ Dai’s analysis considers trends in youth cigarette, alcohol, and marijuana use individually and in combination. Dual and polyuse are important for individual health. Use of nicotine and marijuana together is more strongly associated with adverse health risk behaviors than use of either alone.⁶ Alcohol and marijuana use may make tobacco cessation more difficult.⁷ Importantly, rising polyuse prevalence signals a need for more comprehensive substance use control and prevention.

The cross-sectional time series analysis draws data from the Youth Risk Behavior Survey (YRBS), an national survey of US high school students performed every odd year. For cigarettes, alcohol, and marijuana, Dai examined linear trends in using only one, two, or all three products from 1991 to 2017. Use of only cigarettes and only alcohol declined. However, use of only marijuana increased by a factor of 10: from 0.6% to 6.3%. Meanwhile, dual use of alcohol and marijuana more than doubled, whereas cigarette and marijuana dual use effectively stayed flat. Highlighting pronounced increases in marijuana-only use, particularly among girls and racial/ethnic minorities, while noting the fewer intervention and prevention programs for marijuana compared with tobacco, Dai called for “special focus” on marijuana prevention.

News coverage of the publication largely focused on marijuana, often overlooking tobacco and alcohol.⁸ The 10-fold increase in marijuana-only use, although headline grabbing, obscures that overall marijuana use had increased more gradually and, at 20% in 2017,¹ substantially exceeded the widely cited 6.3% prevalence of marijuana-only use. Declining cigarette and alcohol use, coinciding with rising marijuana use, shifted the typical profile of youth substance use. In 1991, most users of cigarettes, alcohol, or both did not use marijuana; by 2017, approximately half did. Conversely, the share of marijuana users who smoke or drink shrank substantially. Substance control messages emphasizing the harms of smoking and drinking remain essential, but better integrated messaging about marijuana use, alone and with other substances, is warranted for youths who today perceive a large gap between the harms of tobacco and marijuana.

In the three years since publication, citing works have expanded on this article’s findings, with more detailed pictures of polysubstance use over time. In one study, investigators queried another national time series study to identify specific periods when marijuana use was rising fastest.⁹ In another, researchers prospectively followed a more recent youth cohort into the first years beyond high school.¹⁰ The work confirmed high levels of dual or polyuse patterns featuring marijuana and additionally revealed a plurality of substance users whose use increased sharply after high school. School-based surveillance may miss climbing levels of substance use in early adulthood, a population in need of more effective prevention.

Among potential lessons is that substance use prevention should not be siloed by product, particularly that of tobacco and marijuana. Not only do many youths consume both tobacco and marijuana, but dual use may be catalyzed when tobacco and other nicotine products are repurposed for marijuana consumption, as in the case of cigar-wrapped marijuana blunts. Given that blunt use is facilitated by the widespread availability of cheap, flavored small cigars,¹¹ tobacco control measures, such as flavor bans that include cigars, could have implications for marijuana use. Similarly, electronic devices for aerosolizing nicotine can be redesigned or repurposed for vaping marijuana products, a trend that gained national attention when a 2019 outbreak of severe lung injury was tied to tainted marijuana cartridges.¹² Thus, policies, marketing, and public communication about vaping nicotine could also plausibly influence perceptions of and access to vaping marijuana.

Indeed, current and future developments in tobacco, nicotine, and marijuana policy all may shape which trends identified in Dai’s study continue. Although the most recent YRBS wave (2019)¹ showed a further decline in cigarette smoking, there was a tremendous surge in electronic vapor product use, from 13% to 33%—a level of youth nicotine use not seen since the grim days three decades before. As of this writing, Food and Drug Administration authorizations are pending for electronic cigarette products with the largest share of the US market. Those decisions may have long-lasting implications as the agency weighs potential benefits to adult smokers against demonstrated risks to youths.

Further state-level, and potentially federal-level, marijuana legalization is possible, perhaps likely. There is conflicting evidence on whether state-level legalization is tied to short-term increases in youth marijuana use.^13,14 It is certain that marijuana use is gaining social acceptance over recent decades and decreasingly being perceived as harmful, particularly among youths.⁴ Couple these changing attitudes with potential for a more commercialized marijuana industry, and the public health perils are easy to envision. The potential consequences of marijuana policy changes for children and adolescents deserve greater consideration.¹⁵

The featured publication uncovered youth substance use patterns visible only over time, in this case, decades. This highlights the value of ongoing, high-quality national surveillance. More frequent and more nimble surveillance is also needed to capture trends that emerge quickly, such as between biennial YRBS waves. Research should keep up with emerging products and shifting use patterns by incorporating up-to-date tobacco and marijuana product terminology and explicitly measuring dual and polyuse behaviors. Additionally, describing trends among vulnerable groups, although imperative, is just one step toward health equity: more detailed surveillance must help to advance tailored prevention and treatment.

For all the public health progress achieved in reducing youth cigarette and alcohol use, youth vaping, marijuana use, and polysubstance use deserve attention and action. Further research on the short-term and long-term health effects of marijuana and polysubstance use among youths is essential for informing effective public health practice and policy. Understanding the potential harms, the drivers of use, and how products relate to each other better equips researchers, policymakers, educators, and parents to approach youth substance use prevention comprehensively.