Adolescent Δ8-THC and Marijuana Use in the US.

Importance: Gummies, flavored vaping devices, and other cannabis products containing psychoactive hemp-derived Δ8-tetrahydrocannabinol (THC) are increasingly marketed in the US with claims of being federally legal and comparable to marijuana. National data on prevalence and correlates of Δ8-THC use and comparisons to marijuana use among adolescents in the US are lacking. Objective: To estimate the self-reported prevalence of and sociodemographic and policy factors associated with Δ8-THC and marijuana use among US adolescents in the past 12 months. Design, Setting, and Participants: This nationally representative cross-sectional analysis included a randomly selected subset of 12th-grade students in 27 US states who participated in the Monitoring the Future Study in-school survey during February to June 2023. Exposures: Self-reported sex, race, ethnicity, and parental education; census region; state-level adult-use (ie, recreational) marijuana legalization (yes vs no); and state-level Δ8-THC policies (regulated vs not regulated). Main Outcomes and Measures: The primary outcome was self-reported Δ8-THC and marijuana use in the past 12 months (any vs no use and number of occasions used). Results: In the sample of 2186 12th-grade students (mean age, 17.7 years; 1054 [48.9% weighted] were female; 232 [11.1%] were Black, 411 [23.5%] were Hispanic, 1113 [46.1%] were White, and 328 [14.2%] were multiracial), prevalence of self-reported use in the past 12 months was 11.4% (95% CI, 8.6%-14.2%) for Δ8-THC and 30.4% (95% CI, 26.5%-34.4%) for marijuana. Of those 295 participants reporting Δ8-THC use, 35.4% used it at least 10 times in the past 12 months. Prevalence of Δ8-THC use was lower in Western vs Southern census regions (5.0% vs 14.3%; risk difference [RD], -9.4% [95% CI, -15.2% to -3.5%]; adjusted risk ratio [aRR], 0.35 [95% CI, 0.16-0.77]), states in which Δ8-THC was regulated vs not regulated (5.7% vs 14.4%; RD, -8.6% [95% CI, -12.9% to -4.4%]; aRR, 0.42 [95% CI, 0.23-0.74]), and states with vs without legal adult-use marijuana (8.0% vs 14.0%; RD, -6.0% [95% CI, -10.8% to -1.2%]; aRR, 0.56 [95% CI, 0.35-0.91]). Use in the past 12 months was lower among Hispanic than White participants for Δ8-THC (7.3% vs 14.4%; RD, -7.2% [95% CI, -12.2% to -2.1%]; aRR, 0.54 [95% CI, 0.34-0.87]) and marijuana (24.5% vs 33.0%; RD, -8.5% [95% CI, -14.9% to -2.1%]; aRR, 0.74 [95% CI, 0.59-0.94]). Δ8-THC and marijuana use prevalence did not differ by sex or parental education. Conclusions and Relevance: Δ8-THC use prevalence is appreciable among US adolescents and is higher in states without marijuana legalization or existing Δ8-THC regulations. Prioritizing surveillance, policy, and public health efforts addressing adolescent Δ8-THC use may be warranted.

Nicotine use among reservation-area American Indian adolescents compared with a national sample.

BACKGROUND: Past research has found significant nicotine use disparities for reservation-area American Indian adolescents when compared to national levels. However, adolescent nicotine use has changed markedly, with reduced smoking and rapid increases in nicotine vaping. This study presents 2021-2022 prevalence estimates of tobacco product use, perceived harm and availability for reservation-area American Indian youth, with comparisons to the Monitoring the Future (MTF) national study. METHODS: Participants were 8th, 10th and 12th grade students. American Indian data were 33 reservation-area schools in 2021-2022 (n=2420); MTF data were 308 schools in Spring 2022 (n=31,438). Measures were lifetime, 30-day cigarette smoking, smokeless tobacco use, and nicotine vaping; past-year nicotine vaping; daily smoking; perceived harmfulness and availability of these tobacco products. Prevalence and 95% confidence intervals were computed by grade. RESULTS: Estimated prevalence of lifetime, monthly and daily cigarette smoking among American Indian 8th and 10th graders was higher than national levels. Nicotine vaping prevalence was similar between samples. American Indian students were less likely to report tobacco product use poses great risk, but also less likely to report tobacco products are easily available. CONCLUSIONS: Although estimated smoking prevalence among American Indian 8th and 10th graders was higher than national levels, prevalence appears lower than reported in earlier studies, suggesting declining disparities. Prevalence of nicotine vaping among reservation-area American Indian adolescents generally mirrors the national population; however, a lower percentage reported regular nicotine vaping poses a serious risk. This discrepancy suggests a need for prevention and intervention efforts culturally tailored for this population.

A Comparison of COVID-19 Outcomes Between Reservation-Area American Indian and U.S. National Students.

Introduction: This study presents data from 2 population-based surveys of youth (reservation-area American Indian adolescents and U.S. adolescents) on self, family, and friend morbidity and changes in substance use and negative impacts during COVID-19. Methods: Data were obtained in spring 2021 from surveys of American Indian students living on or near reservations (8th grade, n=398; 10th grade, n=367; 12th grade, n=290) and national students from Monitoring the Future (8th grade, n=11,446; 10th grade, n=11,792; 12th grade, n=9,022). The main outcomes were COVID-19 testing, perceived morbidity/mortality, substance-use changes, and emotional changes during COVID-19. Results: The American Indian sample had a greater proportion of testing (e.g., American Indian 8th grade: 58.1% [95% CI=48.6, 68.8]; Monitoring the Future 8th grade: 43.6% [95% CI=39.8, 47.5]) and friend/family hospitalization (e.g., American Indian 8th grade: 36.2% [95% CI=26.2, 47.5]; Monitoring the Future 8th grade: 11.9% [95% CI=10.6, 13.3]). Across grades, greater proportions of the national sample reported increased anxiety, anger, boredom, loneliness, depression, worry, and trouble concentrating, whereas greater proportions of reservation-area American Indians reported decreased anxiety, loneliness, and depression. Conclusions: Findings indicate that reservation-area American Indian youth experienced unique health consequences 1 year into the COVID-19 pandemic compared with national students, illustrating the need for American Indian-specific COVID-19 public health monitoring and response.

Recent, national trends in US adolescent use of menthol and non-menthol cigarettes.

OBJECTIVE: In light of the current U.S. Food and Drug Administration (FDA) proposal to ban menthol cigarettes, this study updates trends in menthol cigarette use among adolescents age 13-18 years up to the year 2020. The study considers a potential role for the ban to reduce black/non-black disparities in menthol cigarette use, as well as a counterargument that a ban is not necessary because menthol use is already diminishing. METHODS: Data are from annual, cross-sectional, nationally representative Monitoring the Future (MTF) surveys of 85 547 8th, 10th and 12th grade students surveyed between 2012 and 2020. Analyses include trends in past 30-day menthol and non-menthol cigarette smoking among the total adolescent population, as well as stratified by race/ethnicity. RESULTS: Declines in adolescent menthol and non-menthol cigarette smoking continued through 2020 so that in 2018-2020 past 30-day prevalence for each was less than 1% for non-Hispanic black adolescents and less than 2.2% for non-black adolescents. For non-Hispanic black adolescents no smoking declines in mentholated or non-mentholated cigarette use from 2015-2017 to 2018-2020 were statistically significant, in part because prevalence levels approached a floor effect and had little room to fall further. Menthol levels were lower for non-Hispanic black versus all other adolescents in all study years. CONCLUSIONS: Continuing declines in adolescent menthol prevalence indicate that both menthol prevalence and also black/non-black disparities in its use are steadily decreasing. However, these decreases in adolescence will take decades to reach later ages through generational replacement. Efforts to accelerate menthol decreases will require new initiatives to increase cessation among adult menthol users.

Alcohol use and the COVID-19 pandemic: Historical trends in drinking, contexts, and reasons for use among U.S. adults.

OBJECTIVE: The current study used U.S. national data to examine drinking trends prior to and during the COVID-19 pandemic in 2020, focusing on changes in U.S. young- and middle-adult alcohol prevalence, frequency, and drinking contexts and reasons, and whether they differed by age and college status. METHODS: Data from 2015 to 2020 from 16,987 young adults (ages 19-30) and 23,584 middle adults (ages 35-55) in the national Monitoring the Future study were used to model historical trends and potential 2020 shifts (data collection April 1 to November 30, 2020) in prevalence (30-day, daily, binge drinking) and frequency (30-day, binge drinking). For young adults, data on drinking contexts and negative affect reasons for drinking were examined. Moderation by age and college status was also tested. RESULTS: 2020 was associated with (1) downward deviation in 30-day (young and middle adults) and binge drinking (young adults) prevalence; (2) upward deviation in daily drinking prevalence (middle adults); (3) among drinkers, upward deviation in frequency of 30-day (young and middle adults) and binge drinking (young adults); and (4) changes in drinking contexts and reasons among drinkers. Among college students, in particular, 2020 was associated with a downward deviation from expected historical trends in drinking prevalence. Upward deviations in daily prevalence and both binge and 30-day drinking frequency were stronger at ages 25-30 (vs. 19-24) and 35-45 (vs. 50-55). CONCLUSIONS: Among U.S. young and middle adults, deviations from expected historical trends in population alcohol use that occurred during the pandemic included decreases in alcohol use prevalence, increases in alcohol use frequency, and increases in the use of alcohol to relax/relieve tension and because of boredom. These shifts were likely due, in part, to drinking while alone and at home-which increased during the pandemic.

Adolescent Cannabis Users Who Have Never Smoked A Combustible Cigarette: Trends and Level of Addictive Drug Use from 1976 to 2020.

Background: Adolescents cannabis users are at a substantially elevated risk for use of highly addictive drugs such as cocaine, heroin, and nonmedical use of prescription drugs. Unknown is whether this elevated risk applies to adolescent cannabis users who have never smoked a combustible cigarette, a group that has grown considerably in size in recent years. This study documents the recent growth in the proportion of adolescent cannabis users who abstain from combustible cigarette use, and examines their probability for use of addictive drugs. Methods: Data are annual, cross-sectional, nationally-representative Monitoring the Future surveys of 607,932 U.S. 12th grade students from 1976-2020. Results: Among ever cannabis users, the percentage who had never smoked a combustible cigarette grew from 11% in 2000 to 58% in 2020. This group had levels of addictive drug use that were 8% higher than their peers. In comparison, adolescents who had ever used cannabis - regardless of whether they had ever smoked a cigarette - had levels of addictive drug use 500% higher than their peers. Conclusions: Adolescent cannabis users who have not smoked a combustible cigarette have much lower levels of addictive drug use than the group of cannabis users as a whole. These results suggest policies and laws aimed at reducing adolescent prevalence of addictive drugs may do better to focus on cigarette use of adolescent cannabis users rather than cannabis use per se.

Nicotine dependence symptoms in U.S. youth who use JUUL E-cigarettes.

PURPOSE: To estimate the prevalence, patterns, and correlates of self-reported nicotine dependence symptoms among U.S. youth who use JUUL - a widely-sold e-cigarette brand - in 2019 and compare findings to nicotine dependence symptoms in youth who smoke cigarettes. METHODS: Data were from a nationally-representative subsample of 8th, 10th, and 12th grade students in the Monitoring the Future Study who had used JUUL or cigarettes in the past 30 days. Participants self-reported presence/absence of 9 different nicotine dependence symptoms for JUUL or cigarettes. Weighted percentages for JUUL or cigarette nicotine dependence symptom status (≥1 vs. 0 symptoms) and severity (count, range: 0-9) were calculated. Among JUUL users, we estimated associations of sociodemographic characteristics and other substance use with nicotine dependence and severity. RESULTS: Among 1,748 past 30-day JUUL users, 41.3 % screened positive for ≥1 nicotine dependence symptoms; the mean symptom count was 1.6 (SD = 2.6). Non-nicotine substance use and more frequent JUUL use was associated with significantly greater odds of dependence and more severe dependence symptoms in multivariable models. The severity distribution of most (craving) and least (inability to quit) dependence symptom types observed in JUUL dependence paralleled those observed in analysis of combustible cigarette dependence symptoms in past 30-day smokers. CONCLUSION: A substantial proportion of U.S. adolescent JUUL users reported symptoms of nicotine dependence, which is greater for those who vape more frequently and use other substances. Nicotine dependence screening, prevention, and regulatory policies addressing use of JUUL or similar e-cigarette products should be considered to protect U.S. youth.

The impact of survey mode on US national estimates of adolescent drug prevalence: results from a randomized controlled study.

BACKGROUND AND AIMS: Increasing numbers of school-based drug surveys are transitioning data collection to electronic tablets from paper-and-pencil, which may produce a survey mode effect and consequent discontinuity in time trends for population estimates of drug prevalence. This study tested whether (a) overall, self-reported drug use prevalence is higher on electronic tablets versus paper-and-pencil surveys, (b) socio-demographics moderate survey mode effects and (c) levels of missing data are lower for electronic tablet versus paper-and-pencil modes. DESIGN: A randomized controlled experiment. SETTING: Results are nationally representative of students in the contiguous United States. PARTICIPANTS: A total of 41 866 8th, 10th and 12th grade students who participated in the 2019 Monitoring the Future school-based survey administration. INTERVENTION AND COMPARATOR: Surveys were administered to students in a randomly selected half of schools with electronic tablets (intervention) and with paper-and-pencil format (comparator) for the other half. MEASUREMENTS: Primary outcome was the total number of positive drug use responses. Secondary outcomes were the percentage of respondents completing all drug questions, percentage of drug questions unanswered and mean number of missing drug items. FINDINGS: The relative risk (RR) for total number of positive drug use responses for electronic tablets versus paper-and-pencil surveys were small and their 95% confidence intervals (CI) included the value of one for reporting intervals of life-time (RR = 1.03; 95% CI, 0.93-1.14), past 12 months (RR = 1.01; 95% CI, 0.91-1.11), past 30 days (RR = 1.05; 95% CI, 0.93-1.20) and for heavy use (RR = 1.10; 95% CI, 0.93-1.29). Multiplicative interaction tests indicated no moderation of these relative risks by race (white versus non-white), population density, census region, public/private school, year of school participation, survey version or non-complete drug responses. Levels of missing data were significantly lower for electronic tablets versus paper-and-pencil surveys. CONCLUSIONS: Adolescent drug prevalence estimates in the United States differed little across electronic tablet versus paper-and-pencil survey modes, and showed little to no effect modification by socio-demographics. Levels of missing data were lower for electronic tablets.

Prospective associations of e-cigarette use with cigarette, alcohol, marijuana, and nonmedical prescription drug use among US adolescents.

BACKGROUND: As e-cigarette use continues to increase in the U.S., research is needed to understand its prospective risk for cigarette smoking and other substance use in young adulthood, including alcohol, marijuana, and nonmedical prescription drugs (NMPDs). METHODS: This study used data from the Monitoring the Future (MTF) study a nationally representative annual survey of 12th graders (modal age 18) in the US. The analytic sample included 2014-2016 MTF cohorts that were selected and completed follow up one year later (modal age 19; n = 717). Using logistic regression, we examined cross-sectional and prospective associations of past 30-day e-cigarette use with past 30-day cigarette, alcohol, marijuana, and NMPD use. We examined prospective associations among the full sample and associations with incidence of each of these substances among those who reported no history of use in 12th grade. RESULTS: In cross-sectional analysis, those who reported past 30-day e-cigarette use at age 18 were more likely to report past 30-day cigarette use, alcohol use, marijuana use, and NMPD use at age 19. In multivariable longitudinal analysis, past 30-day e-cigarette users at age 18 were more likely to report past 30-day cigarette, marijuana, and NMPD use at age 19, including e-cigarette users who had no history of using these substances at age 18. CONCLUSIONS: This study suggests that e-cigarette use may be an indicator of future substance use risk in young adulthood. Adolescent e-cigarette users may benefit from secondary prevention efforts to mitigate this risk.

Risk of Persistence and Progression of Use of 5 Cannabis Products After Experimentation Among Adolescents.

Importance: While a diverse array of cannabis products that may appeal to youth is currently available, it is unknown whether the risk of persistent cannabis use and progression to higher frequency of use after experimentation differs among cannabis products. Objective: To estimate the comparative relative risk of experimental use of 5 cannabis products on use status and frequency of use among adolescents during 12 months of follow-up. Design, Setting, and Participants: In this cohort study, data were collected from 3065 adolescents at 10 high schools in southern California, with baseline data collected in spring 2016, when students were in 11th grade, and 6-month and 12-month follow-up surveys collected in fall 2016 and spring 2017, when students were in 12th grade. Analyses, conducted from April to June 2019, were restricted to 2685 participants who were light or nonusers of any cannabis product (ie, ≤2 days in the past 30 days) at baseline. Exposures: Number of days of use of each cannabis product (ie, combustible, blunts, vaporized, edible, or concentrated) in the past 30 days at baseline (ie, 1-2 vs 0 days). Main Outcomes and Measures: Past 6-month use (ie, yes vs no) and number of days of use in the past 30 days at 6-month and 12-month follow-ups for each product. Results: Of 2685 individuals in the analytic sample, 1477 (55.0%) were young women, the mean (SD) age was 17.1 (0.4) years, and a plurality (1231 [46.6%]) were Hispanic individuals. Among them, 158 (5.9%) reported combustible cannabis use on 1 to 2 days of the past 30 days at baseline, 90 (3.4%) reported blunt use, 78 (2.9%) reported edible cannabis use, 17 (0.6%) reported vaping cannabis, and 15 (0.6%) reported using cannabis concentrates. In regression models adjusting for demographic characteristics and poly-cannabis product use, statistically stronger associations of baseline use with subsequent past 6-month use at the 6-month and 12-month follow-ups were observed for combustible cannabis use (odds ratio, 6.01; 95% CI, 3.66-9.85) and cannabis concentrate use (odds ratio, 5.87; 95% CI, 1.18-23.80) compared with use of blunts (OR, 2.77; 95% CI, 1.45-5.29) or edible cannabis (OR, 3.32; 95% CI, 1.86-5.95) (P for comparison < .05); vaporized cannabis use (OR, 5.34; 95% CI, 1.51-11.20) was not significantly different from the other products. In similarly adjusted models, we found the association of cannabis use at baseline with mean days of use at the 6-month and 12-month follow-ups was significantly stronger for cannabis concentrate than for other cannabis products; participants who had used cannabis concentrate on 1 to 2 of the past 30 days at baseline (vs 0 days) used cannabis concentrate a mean of 9.42 (95% CI, 2.02-35.50) more days in the past 30 days at the 6-month and 12-month follow-ups (P for comparison < .05). Conclusions and Relevance: Cannabis control efforts should consider targeting specific cannabis products, including combustible cannabis and cannabis concentrate, for maximum public health consequences.

Association of Nonmedical Prescription Opioid Use With Subsequent Heroin Use Initiation in Adolescents.

IMPORTANCE: There is concern that nonmedical prescription opioid use is associated with an increased risk of later heroin use initiation in adolescents, but to our knowledge, longitudinal data addressing this topic are lacking. OBJECTIVE: To determine whether nonmedical prescription opioid use is associated with subsequent initiation of heroin use in adolescents. DESIGN, SETTING, AND PARTICIPANTS: This prospective longitudinal cohort study conducted in 10 high schools in Los Angeles, California, administered 8 semiannual surveys from 9th through 12th grade that assessed nonmedical prescription opioid use, heroin use, and other factors from October 2013 to July 2017. Students were baseline never users of heroin recruited through convenience sampling. Cox regression models tested nonmedical prescription opioid use statuses at survey waves 1 through 7 as a time-varying and time-lagged regressor and subsequent heroin use initiation across waves 2 to 8 as the outcome. EXPOSURES: Self-reported nonmedical prescription opioid use (past 30-day [current] use vs past 6-month [prior] use without past 30-day use vs no past 6-month use) at each wave from 1 to 7. MAIN OUTCOMES AND MEASURES: Self-reported heroin use initiation (yes/no) during waves 2 to 8. RESULTS: Of 3298 participants, 1775 (53.9%) were adolescent girls, 1563 (48.3%) were Hispanic, 548 (17.0%) were Asian, 155 (4.8%) were African American, 529 (16.4%) were non-Hispanic white, and 220 (6.8%) were multiracial. Among baseline never users of heroin in ninth grade with valid data (3298 [97% of cohort enrollees]; mean [SD] age, 14.6 [0.4] years), the number of individuals with outcome data available at each follow-up ranged from 2987 (90.6%) to 3200 (97.0%). The mean per-wave prevalence of prior and current nonmedical prescription opioid use from waves 1 to 7 was 1.9% and 2.7%, respectively. Seventy students (2.1%) initiated heroin use during waves 2 to 8. Prior vs no (hazard ratio, 3.59; 95% CI, 2.14-6.01; P < .001) and current vs no (hazard ratio, 4.37; 95% CI, 2.80-6.81; P < .001) nonmedical prescription opioid use were positively associated with subsequent heroin use initiation. For no, prior, and current nonmedical prescription opioid use statuses at waves 1 to 7, the estimated cumulative probabilities of subsequent heroin use initiation by wave 8 (42-month follow-up) were 1.7%, 10.7%, and 13.1%, respectively. In covariate-adjusted models, associations were attenuated but remained statistically significant and current nonmedical prescription opioid use risk estimates were stronger than corresponding associations of nonopioid substance use with subsequent heroin use initiation. CONCLUSIONS AND RELEVANCE: Nonmedical prescription opioid use was prospectively associated with subsequent heroin use initiation during 4 years of adolescence among Los Angeles youth. Further research is needed to understand whether this association is causal.

A Sequential Mixed-Mode Experiment in the U.S. National Monitoring the Future Study.

The national Monitoring the Future (MTF) study examines substance use among adolescents and adults in the United States and has used paper questionnaires since it began in 1975. The current experiment tested three conditions as compared to the standard MTF follow-up protocol (i.e., MTF Control) for the first MTF follow-up survey at ages 19/20 years (i.e., one or two years after high school graduation). The MTF Control group included participants who completed in-school baseline surveys in the 12th grade in 2012-2013 and who were selected to participate in the first follow-up survey in 2014 (n = 2,451). A supplementary sample of participants who completed the 12th grade baseline survey in 2012 or 2013 but were not selected to participate in the main MTF follow-up (n = 4,950) were recruited and randomly assigned to one of three experimental conditions: (1) Mail Push, (2) Web Push, (3) Web Push + E-mail. Results indicated that the overall response rate was lower in Condition 2 compared to MTF Control and to Condition 1; there were no differences between Condition 3 and other conditions. Web response was highest in Condition 3; among web responders, smartphone response was also highest in Condition 3. Subgroup differences also emerged such that, for example, compared to white participants, Hispanics had greater odds of web (versus paper) response and blacks had greater odds of smartphone (versus computer or tablet) response. Item nonresponse was lowest in the Web Push conditions (compared to MTF Control) and on the web survey (compared to paper). Compared to MTF Control, Condition 3 respondents reported higher rates of alcohol use in the past 30 days. The total cost was lowest for Condition 3. Overall, the Condition 3 Web Push + E-mail design is promising. Future research is needed to continue to examine the implications of web and mobile response in large, national surveys.

Reasons for Vaping Among U.S. 12th Graders.

INTRODUCTION: Vaping has recently increased in popularity among adolescents. Little is known about heterogeneity of vapers, particularly in terms of why they vape. Identifying major subgroups of adolescent vapers by reasons for vaping is important to understand adolescent vaping behavior and to identify those most at risk for other substance use. METHODS: Monitoring Future data from 2015 and 2016 were used in a latent class analysis to identify subgroups of 12th graders based on their endorsement of 10 potential reasons for vaping. Multinomial regression with a latent class outcome was used to predict class membership. RESULTS: Three distinct classes of vapers were identified: adolescents who were (1) Vaping to Experiment (29.4%), (2) Vaping to Replace Cigarettes (7.3%), and (3) Vaping for Taste + Entertainment (63.4%). Vaping only flavors was associated with lower odds of membership and cigarette use was associated with higher odds of membership in the Vaping to Replace Cigarettes subgroup, and marijuana was associated with lower odds of membership in the Vaping to Experiment subgroup, compared with the Vaping for Taste + Entertainment subgroup. CONCLUSIONS: This study identified multiple subgroups of vapers based on reasons for vaping. Whereas a small subgroup vaped for reasons related to cigarette use, most adolescent vapers reported vaping for reasons unrelated to cigarette use. There were considerable differences in primary reasons for vaping and risk for traditional cigarette and other substance use, suggesting different intervention strategies may be needed for different subgroups of vapers.

Current High-Intensity Drinking Among Eighth and Tenth Grade Students in the U.S.

INTRODUCTION: This study assessed the prevalence of current high-intensity drinking (i.e., having ten or more drinks in a row in the past 2 weeks) among national samples of U.S. eighth and tenth grade students (at modal ages 14 and 16 years, respectively). METHODS: Data on high-intensity drinking were provided by 10,210 students participating in the nationally representative Monitoring the Future study in 2016, and analyzed in 2016-2017. Prevalence levels and interactions between grade and key covariates were estimated using procedures that adjusted for the Monitoring the Future study's complex sampling design. RESULTS: Approximately 2% of adolescents reported current high-intensity drinking, with significant differences by grade (1.2% of eighth graders; 3.1% of tenth graders) and gender (1.7% female; 2.3% male). High-intensity drinking was significantly higher among eighth and tenth grade students who reported any cigarette or marijuana use than among students who reported never using either substance. CONCLUSIONS: A meaningful percentage of young adolescents in the U.S. engage in high-intensity drinking.

Age-Specific Prevalence of Binge and High-Intensity Drinking Among U.S. Young Adults: Changes from 2005 to 2015.

BACKGROUND: This study examined changes during the past decade, from 2005 to 2015, in binge and high-intensity drinking in 7 separate age groups of U.S. 12th graders and young adults. METHODS: National longitudinal data (N = 6,711) from Monitoring the Future were used to examine trends in consuming 5+, 10+, and 15+ drinks on the same occasion in the past 2 weeks from ages 18 to 29/30 overall and by gender. Results were compared with trends in past 12-month and 30-day alcohol use for the same age groups. RESULTS: Between 2005 and 2015, binge (5+) and high-intensity drinking (10+, 15+) generally decreased for individuals in their early 20s, remained somewhat stable for individuals in their mid-20s, and increased for individuals at the end of young adulthood (age 29/30). The observed historical trends in binge and high-intensity drinking were similar to those for past 12-month and past 30-day alcohol use for those aged 18 to 20, but diverged for most other age groups in young adulthood. Trends were generally similar for men and women, except that the increase in prevalence began earlier in young adulthood for women than for men. CONCLUSIONS: Binge and high-intensity drinking among U.S. 12th graders and young adults are dynamic phenomena. Prevention and intervention efforts aimed at reducing the harms resulting from 5+, 10+, and 15+ drinking should acknowledge and focus on differences in trends in these behaviors by age and gender.

Association Between Initial Use of e-Cigarettes and Subsequent Cigarette Smoking Among Adolescents and Young Adults: A Systematic Review and Meta-analysis.

Importance: The public health implications of e-cigarettes depend, in part, on whether e-cigarette use affects the risk of cigarette smoking. Objective: To perform a systematic review and meta-analysis of longitudinal studies that assessed initial use of e-cigarettes and subsequent cigarette smoking. Data Sources: PubMed, EMBASE, Cochrane Library, Web of Science, the 2016 Society for Research on Nicotine and Tobacco 22nd Annual Meeting abstracts, the 2016 Society of Behavioral Medicine 37th Annual Meeting & Scientific Sessions abstracts, and the 2016 National Institutes of Health Tobacco Regulatory Science Program Conference were searched between February 7 and February 17, 2017. The search included indexed terms and text words to capture concepts associated with e-cigarettes and traditional cigarettes in articles published from database inception to the date of the search. Study Selection: Longitudinal studies reporting odds ratios for cigarette smoking initiation associated with ever use of e-cigarettes or past 30-day cigarette smoking associated with past 30-day e-cigarette use. Searches yielded 6959 unique studies, of which 9 met inclusion criteria (comprising 17 389 adolescents and young adults). Data Extraction and Synthesis: Study quality and risk of bias were assessed using the Newcastle-Ottawa Scale and the Risk of Bias in Non-randomized Studies of Interventions tool, respectively. Data and estimates were pooled using random-effects meta-analysis. Main Outcomes and Measures: Among baseline never cigarette smokers, cigarette smoking initiation between baseline and follow-up. Among baseline non-past 30-day cigarette smokers who were past 30-day e-cigarette users, past 30-day cigarette smoking at follow-up. Results: Among 17 389 adolescents and young adults, the ages ranged between 14 and 30 years at baseline, and 56.0% were female. The pooled probabilities of cigarette smoking initiation were 30.4% for baseline ever e-cigarette users and 7.9% for baseline never e-cigarette users. The pooled probabilities of past 30-day cigarette smoking at follow-up were 21.5% for baseline past 30-day e-cigarette users and 4.6% for baseline non-past 30-day e-cigarette users. Adjusting for known demographic, psychosocial, and behavioral risk factors for cigarette smoking, the pooled odds ratio for subsequent cigarette smoking initiation was 3.62 (95% CI, 2.42-5.41) for ever vs never e-cigarette users, and the pooled odds ratio for past 30-day cigarette smoking at follow-up was 4.28 (95% CI, 2.52-7.27) for past 30-day e-cigarette vs non-past 30-day e-cigarette users at baseline. A moderate level of heterogeneity was observed among studies (I2 = 60.1%). Conclusions and Relevance: e-Cigarette use was associated with greater risk for subsequent cigarette smoking initiation and past 30-day cigarette smoking. Strong e-cigarette regulation could potentially curb use among youth and possibly limit the future population-level burden of cigarette smoking.

Risk is still relevant: Time-varying associations between perceived risk and marijuana use among US 12th grade students from 1991 to 2016.

BACKGROUND: Perceived risk of harm has long been a key preventive factor for adolescent marijuana use. However, in recent years, perceived risk has decreased markedly and marijuana use has increased only slightly, leading to new questions about their association. This study investigates the magnitude and stability of the US adolescent marijuana risk/use association from 1991 to 2016, overall and by gender and race/ethnicity. METHODS: Self-reported data on past 12-month marijuana use, perceived risk of regular marijuana use, gender, and race/ethnicity were obtained from 275,768 US 12th grade students participating in the nationally representative Monitoring the Future study. Time-varying effect modeling (TVEM) was used to examine the marijuana risk/use association over time. RESULTS: Both before and after controlling for gender and race/ethnicity, perceived risk was a strong protective factor against adolescent marijuana use. The magnitude of the great risk/use association strengthened for Hispanic students; remained generally stable over time for 12th graders overall, males, females, and White students; and weakened for Black students. The magnitude of the moderate risk/use association strengthened for 12th graders overall, males, females, White and Hispanic students, but did not continue to strengthen for Black students from 2005 onwards. In general, marijuana use prevalence decreased over time within all levels of perceived risk. CONCLUSIONS: Perceived risk remains a strong protective factor for adolescent marijuana use, and the protective association for moderate risk (vs. no/slight risk) is actually increasing over time. Results suggest that accurate and credible information on the risks associated with marijuana use should remain a key component of prevention efforts.

The Influence of College Attendance on Risk for Marijuana Initiation in the United States: 1977 to 2015.

OBJECTIVES: To examine a potential increase in marijuana initiation among US college students as compared with their age peers not in college before and after 2013, a watershed year for increasing tolerance of marijuana use in the United States. METHODS: Data come from the Monitoring the Future study, which has followed longitudinal panels drawn from annual nationally representative, baseline samples of 12th-grade students starting with the class of 1976. We studied panel members aged 19 to 22 years who had never used marijuana by 12th grade between 1977 and 2015. RESULTS: College as a risk factor for marijuana initiation has increased significantly since 2013. The increased probability of past-year marijuana use for those enrolled versus not enrolled in college was 51% in 2015, 41% in 2014, and 31% in 2013; it averaged 17% to 22% from 1977 to 2012 among youths who had never used marijuana by 12th grade. CONCLUSIONS: College has grown as a risk factor for marijuana initiation since 2013. Public Health Implications. College students are in position to usher in new increases in population marijuana use unless colleges soon address the issue with new or modified programs for marijuana prevention and intervention.