The great decline in adolescent cigarette smoking since 2000: consequences for drug use among US adolescents.

OBJECTIVE: Adolescent cigarette smoking declined steadily and substantially from 2000 to 2018. This paper considers the potential consequences of this 'great decline' for the prevalence of other drug use among adolescents. METHODS: Data are annual, cross-sectional, nationally representative Monitoring the Future surveys of more than 1.2 million US students in 12th, 10th and 8th grades from 2000 to 2018. Analyses include trends in the past 12 months' non-medical amphetamine, tranquillisers and opioid use overall, among ever and never cigarette smokers, and projected if adolescent cigarette smoking levels had remained at 2000 levels. RESULTS: Within groups of ever and never cigarette smokers, the prevalence for each of the three substances has either changed little or overall increased in 2018 as compared with 2000. When the two groups were combined into one pool, the overall prevalence for each of the drugs declined by about half. The decline resulted from the growing group of never smokers, whose levels of non-medical drug use over the study period were at least four times lower than the levels of ever smokers. CONCLUSIONS: The results support the 'gateway' prediction that declines in cigarette smoking among adolescents pull downward their non-medical use of amphetamines, tranquillisers and opioids. Continuing to reduce adolescent smoking through policy and programmatic prevention efforts should have further positive spillover effects on adolescent drug use.

Changes in the Order of Cigarette and Marijuana Initiation and Associations with Cigarette Use, Nicotine Vaping, and Marijuana Use: U.S. 12th Grade Students, 2000-2019.

This study (a) examined changes in marijuana and cigarette initiation sequencing and (b) considered implications of such changes for prevention efforts by examining associations between initiation sequencing and current adolescent substance use. Analyses used 2000-2019 cross-sectional data from the national Monitoring the Future (MTF) study (78,252 U.S. 12th grade students). Models examined trends in six distinct patterns of initiation order, and multivariable associations between order of initiation and 30-day cigarette and marijuana use prevalence, cigarette and marijuana use frequency among users, and nicotine and marijuana vaping prevalence. While the percentage of students initiating neither cigarettes nor marijuana increased, increases also were observed in marijuana-only initiation (the fastest-growing pattern) and initiation of marijuana before cigarettes; these increases were accompanied by a significant decrease in cigarette-only initiation. Cigarette use prevalence and frequency were highest among students initiating cigarettes before marijuana; marijuana use prevalence and frequency were highest among students initiating marijuana before cigarettes. Cigarette and marijuana prevalence, as well as marijuana frequency, were lowest among students initiating only a single substance. Nicotine vaping was less prevalent among students initiating a single substance versus both substances, but no significant differences were observed in nicotine vaping prevalence between those initiating only cigarettes versus only marijuana. Implications of these findings for prevention efforts are discussed in the frameworks of both the common liability model and route of administration model.

Shifting Age of Peak Binge Drinking Prevalence: Historical Changes in Normative Trajectories Among Young Adults Aged 18 to 30.

BACKGROUND: This study examined the extent to which the developmental pattern of prevalence of binge drinking in the past 2 weeks from ages 18 through 30 has changed across 29 cohorts of U.S. young adults, and whether the changes differed by gender. METHODS: Analyses used national longitudinal data from 58,019 12th-grade students (from graduating high school classes 1976 to 2004) participating in the Monitoring the Future study followed through modal age 30 (with age 29/30 data collected from 1987 to 2016). Weighted time-varying effect modeling was used to model cohort group differences in age-related patterns of binge drinking. RESULTS: The age of peak binge drinking prevalence increased across cohorts (from age 20 in 1976 to 1985 to 22 in 1996 to 2004 for women, and from 21 in 1976 to 1985 to 23 in 1996 to 2004 for men). Historical change in the developmental pattern of binge drinking across all ages of young adulthood differed for men and women. Even after controlling for key covariates, women in the more recent cohort group reported significantly higher binge drinking prevalence than women in earlier cohorts from ages 21 through 30. Men in the more recent cohort group reported higher binge drinking prevalence at ages 25 to 26, but prevalence levels then converged to those seen in earlier cohort groups by age 30. CONCLUSIONS: An older age of peak binge drinking and a decreased rate of decline in the prevalence of binge drinking in later young adulthood among more recent cohorts have resulted in an extension of individual and societal risks associated with binge drinking, particularly for women, across young adulthood. High-risk alcohol use prevention efforts are needed throughout at least the third decade of life.

Recent increases in depressive symptoms among US adolescents: trends from 1991 to 2018.

BACKGROUND: Mental health problems and mental health related mortality have increased among adolescents, particularly girls. These trends have implications for etiology and prevention and suggest new and emerging risk factors in need of attention. The present study estimated age, period, and cohort effects in depressive symptoms among US nationally representative samples of school attending adolescents from 1991 to 2018. METHODS: Data are drawn from 1991 to 2018 Monitoring the Future yearly cross-sectional surveys of 8th, 10th, and 12th grade students (N = 1,260,159). Depressive symptoms measured with four questions that had consistent wording and data collection procedures across all 28 years. Age-period-cohort effects estimated using the hierarchical age-period-cohort models. RESULTS: Among girls, depressive symptoms decreased from 1991 to 2011, then reversed course, peaking in 2018; these increases reflected primarily period effects, which compared to the mean of all periods showed a gradual increase starting in 2012 and peaked in 2018 (estimate = 1.15, p < 0.01). Cohort effects were minimal, indicating that increases are observed across all age groups. Among boys, trends were similar although the extent of the increase is less marked compared to girls; there was a declining cohort effect among recently born cohorts, suggesting that increases in depressive symptoms among boys are slower for younger boys compared to older boys in recent years. Trends were generally similar by race/ethnicity and parental education, with a positive cohort effect for Hispanic girls born 1999-2004. CONCLUSIONS: Depressive symptoms are increasing among teens, especially among girls, consistent with increases in depression and suicide. Population variation in psychiatric disorder symptoms highlight the importance of current environmental determinants of psychiatric disorder risk, and provide evidence of emerging risk factors that may be shaping a new and concerning trend in adolescent mental health.

Joint Effects of Age, Period, and Cohort on Conduct Problems Among American Adolescents From 1991 Through 2015.

Although arrest rates among juveniles have substantially decreased since the 1990s, US national trends in conduct problems are unknown. Population variation in conduct problems would imply changes in the social environment, which would include emergent or receding risk factors. In the present study, we separated age, period, and cohort effects on conduct problems using nationally representative surveys of 375,879 US students conducted annually (1991-2015). The summed score of 7 items measuring the frequency of conduct problems was the outcome. Conduct problems have decreased during the past 25 years among boys; the total amount of the decrease was approximately 0.4 standard deviations (P < 0.01), and by item prevalence, the total amount of the decrease was 8%-11%. Declines are best explained by period effects beginning approximately in 2008, and a declining cohort effect beginning among those born after 1992, which suggests not only declines in population levels, but more rapid declines among younger cohorts of boys. Trends were also consistent with age-period-cohort effects on evenings spent out, which suggest a possible mechanism. Conduct problems among girls were lower than boys and did not demonstrate trends across time. These changes may reflect the changing nature of adolescence toward less unsupervised interaction.

Patterns of simultaneous and concurrent alcohol and marijuana use among adolescents.

BACKGROUND: Alcohol and marijuana are the most commonly used substances among adolescents but little is known about patterns of co-use. OBJECTIVES: This study examined patterns of concurrent (not overlapping) and simultaneous (overlapping) use of alcohol and marijuana among adolescents. METHODS: Data from US-national samples of 12th graders (N = 84,805, 48.4% female) who participated in the Monitoring the Future study from 1976 to 2016 and who used alcohol and/or marijuana in the past 12 months were used to identify latent classes of alcohol use, marijuana use, and simultaneous alcohol and marijuana (SAM) use. RESULTS: A four-class solution indicated four patterns of use among adolescents: (1) Simultaneous alcohol and marijuana (SAM) use with binge drinking and recent marijuana use (SAM-Heavier Use; 11.2%); (2) SAM use without binge drinking and with recent marijuana use (SAM-Lighter Use; 21.6%); (3) Marijuana use and alcohol use but no SAM use (Concurrent Use; 10.7%); and (4) Alcohol use but no marijuana or SAM use (Alcohol-Only Use; 56.4%). Membership in either SAM use class was associated with a higher likelihood of truancy, evenings out, and use of illicit drugs other than marijuana. SAM-Heavier Use, compared to SAM-Lighter Use, class members were more likely to report these behaviors and be male, and less likely to have college plans. CONCLUSIONS: Among 12th graders who use both alcohol and marijuana, the majority use simultaneously, although not all use heavily. Given the recognized increased public health risks associated with simultaneous use, adolescent prevention programming should include focus on particular risks of simultaneous use.

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.

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.

Discontinuous Patterns of Cigarette Smoking From Ages 18 to 50 in the United States: A Repeated-Measures Latent Class Analysis.

INTRODUCTION: Effective cigarette smoking prevention and intervention programming is enhanced by accurate understanding of developmental smoking pathways across the life span. This study investigated within-person patterns of cigarette smoking from ages 18 to 50 among a US national sample of high school graduates, focusing on identifying ages of particular importance for smoking involvement change. AIMS AND METHODS: Using data from approximately 15,000 individuals participating in the longitudinal Monitoring the Future study, trichotomous measures of past 30-day smoking obtained at 11 time points were modeled using repeated-measures latent class analyses. Sex differences in latent class structure and membership were examined. RESULTS: Twelve latent classes were identified: three characterized by consistent smoking patterns across age (no smoking; smoking < pack per day; smoking pack + per day); three showing uptake to a higher category of smoking across age; four reflecting successful quit behavior by age 50; and two defined by discontinuous shifts between smoking categories. The same latent class structure was found for both males and females, but membership probabilities differed between sexes. Although evidence of increases or decreases in smoking behavior was observed at virtually all ages through 35, 21/22 and 29/30 appeared to be particularly key for smoking category change within class. CONCLUSIONS: This examination of latent classes of cigarette smoking among a national US longitudinal sample of high school graduates from ages 18 to 50 identified unique patterns and critical ages of susceptibility to change in smoking category within class. Such information may be of particular use in developing effective smoking prevention and intervention programming. IMPLICATIONS: This study examined cigarette smoking among a national longitudinal US sample of high school graduates from ages 18 to 50 and identified distinct latent classes characterized by patterns of movement between no cigarette use, light-to-moderate smoking, and the conventional definition of heavy smoking at 11 time points via repeated-measures latent class analysis. Membership probabilities for each smoking class were estimated, and critical ages of susceptibility to change in smoking behaviors were identified.

E-cigarette use as a predictor of cigarette smoking: results from a 1-year follow-up of a national sample of 12th grade students.

OBJECTIVE: To prospectively examine vaping as a predictor of future cigarette smoking among youth with and without previous cigarette smoking experience. A secondary aim is to investigate whether vaping may desensitise youth to the dangers of smoking. METHODS: Analysis of prospective longitudinal panel data from the nationally representative Monitoring the Future study. The analysis is based on 347 12th grade students who were part of a randomly selected subsample that completed in-school surveys in 2014 and were resurveyed 1-year later. RESULTS: Among youth who had never smoked a cigarette by 12th grade, baseline, recent vapers were more than 4 times (relative risk (RR)=4.78) more likely to report past-year cigarette smoking at follow-up, even among youth who reported the highest possible level of perceived risk for cigarette smoking at baseline. Among 12th grade students who had smoked in the past but had not recently smoked at baseline, recent vapers were twice (RR=2.15) as likely to report smoking in the past 12 months at the follow-up. Vaping did not predict cessation of smoking among recent smokers at baseline. Among never-smokers at baseline, recent vapers were more than 4 times (RR=4.73) more likely to move away from the perception of cigarettes as posing a 'great risk' of harm, a finding consistent with a desensitisation process. CONCLUSIONS: These results contribute to the growing body of evidence supporting vaping as a one-way bridge to cigarette smoking among youth. Vaping as a risk factor for future smoking is a strong, scientifically-based rationale for restricting youth access to e-cigarettes.

What are kids vaping? Results from a national survey of US adolescents.

OBJECTIVE: To examine what substances US youth vape. METHODS: Data come from Monitoring the Future, an annual, nationally representative survey of USA 12th-grade, 10th-grade and 8th-grade students. Respondents reported what substance they vaped the last time they used a vaporiser such as an e-cigarette. RESULTS: Among students who had ever used a vaporiser, 65-66% last used 'just flavouring' in 12th, in 10th and in 8th grade, more than all other responses combined. In all three grades, the percentage using 'just flavouring' was above 57% for males, females, African-Americans, Hispanics, Whites, and students both with and without a parent with a college degree. Nicotine use came in a distant second, at about 20% in 12th and 10th grade and 13% in 8th grade. Taking into account youth who vaped nicotine at last use increases national estimates of tobacco/nicotine prevalence in the past 30 days by 24-38% above and beyond cigarette smoking, which is substantial but far less than estimates that assume all vaporiser users inhale nicotine. CONCLUSIONS: These results challenge the common assumption that all vaporiser users inhale nicotine. They (a) call into question the designation of vaporisers and e-cigarettes as ENDS ('Electronic Nicotine Delivery System'), (b) suggest that the recent rise in adolescent vaporiser use does not necessarily indicate a nicotine epidemic, and (c) indicate that vaporiser users can be candidates for primary prevention programmes. Finally, the results suggest the importance of developing different rationales for the regulation of vaporiser devices as compared to the regulation of substances marketed for vaporiser use.

Selected State Policies and Associations With Alcohol Use Behaviors and Risky Driving Behaviors Among Youth: Findings from Monitoring the Future Study.

BACKGROUND: Effective policies that can reduce alcohol use behaviors and impaired driving among young people at a population level are needed. Graduated driver licensing (GDL) laws increase the driving privileges of young novice drivers as they age and gain more driving experience. In this study, we seek to determine the effects of GDLs on risky driving behaviors of youth and to assess if GDLs have an unintended effect on underage drinking behaviors. METHODS: We utilized 2000 to 2013 data on 12th grade students from the Monitoring the Future (MTF) study, an ongoing, annual national survey (since 1975) that studies the substance use behaviors of adolescents, as well as data on GDL laws obtained via the Insurance Institute for Highway Safety (IIHS). We conducted a series of regular logistic regression models that included fixed effects for year and state, and adjusted for demographic characteristics, school characteristics, and other state alcohol policies. RESULTS: Total weighted sample size was 129,289 12th graders. Past month alcohol use and binge drinking (i.e., ≥5 drinks on one occasion) in the past 2 weeks were 45 and 26%, respectively. Seventeen percent of respondents reported riding with a driver who drank alcohol. Nearly 12% reported driving in the past 2 weeks after drinking alcohol, and 7% reported driving after binge drinking. Over half of the students lived in a state with a "good" GDL law. The logistic regression models suggest a link between restrictive GDL policies and a reduction of alcohol use behaviors and risky driving behaviors among youth. CONCLUSIONS: Our findings indicate that the effects of GDLs extend beyond driving-related risks and into other drinking-related behaviors that pose immediate or delayed health risks for young people. We speculate that GDLs may dictate social norms and expectations for youth risk behaviors, and should be maximized throughout the United States.

E-Cigarettes and the Drug Use Patterns of Adolescents.

INTRODUCTION: This study examines the role of e-cigarettes in the drug use patterns of adolescents. Of specific interest is whether adolescent e-cigarette users fall into a group of (1) youth who do not use traditional drugs of abuse or (2) polysubstance users. METHODS: Using latent class analysis, we identify major "classes" of substance users on the basis of recent use of e-cigarettes, alcohol, marijuana, cigarettes, and prescription drugs. Analyses are conducted separately for adolescents in 8th, 10th, and 12th grades. Data come from 16 615 participants in the 2014 Monitoring the Future survey. RESULTS: Youth who do not use traditional drugs of abuse account for about 50% of e-cigarette users in 8th grade, 35% in 10th grade, and 17% in 12th grade. These youth come from a large "low-level users" group found in each grade, characterized by low probability of use for all substances (e-cigarette probability in this group for 8th graders = .046; 10th graders = .071; 12th graders = .027). Other e-cigarette users come from a smaller, "poly-users" group found in each grade, characterized by high-to-moderate probabilities (.83-.21) of using e-cigarettes and other substances. Specific to 12th grade is a third, additional polysubstance group characterized by high likelihood of e-cigarette use (.93). CONCLUSIONS: The proportion of e-cigarette users who do not use traditional drugs of abuse is larger at younger ages. Longitudinal panel studies starting at 8th and 10th grades may best inform the current debate on whether e-cigarette use is a risk or protective factor for future transition to the use of other substances. IMPLICATIONS: The proportion of e-cigarette users who do not use traditional drugs of abuse is larger at younger ages. Longitudinal panel studies starting at 8th and 10th grades may best inform the current debate on whether e-cigarette use is a risk or protective factor for future transition to the use of other substances.

High School Substance Use as a Predictor of College Attendance, Completion, and Dropout: A National Multi-cohort Longitudinal Study.

National data from Monitoring the Future were used to examine patterns and predictors of college attendance. Samples of American 12th-grade students from 1977-2003 were followed for seven years (modal ages 18-25; N=10,020). College attendance and graduation patterns varied considerably over historical time and based on family background. Substance use during high school predicted a greater likelihood of never attending (for cigarettes, illegal drugs), of graduating from a 2-year rather than a 4-year school (for cigarettes), and of dropping out versus graduating from a 4-year school (for cigarettes, marijuana, and other illegal drugs). High school binge drinking predicted lower college dropout, but only in models also controlling for cigarette, marijuana, and other illicit drug use. This study provides a needed overview of adolescent predictors of patterns of college attendance among American young adults over the past three decades.

Foods and beverages offered in US public secondary schools through the National School Lunch Program from 2011-2013: Early evidence of improved nutrition and reduced disparities.

OBJECTIVE: To present data on trends in foods and beverages offered through the National School Lunch Program (NSLP) in public middle and high schools in the years immediately preceding and following implementation of new NSLP standards. METHOD: From 2011 to 2013, primary data collection through the annual Youth, Education, and Society study involved use of mailed questionnaires to obtain data on NSLP meals from schools attended by nationally representative samples of US 8(th), 10(th), and 12(th) grade students (N=792 middle schools and 751 high schools). Each school was weighted to represent the percentage of target grade students enrolled, thus allowing analyses examining changes over time in the percentage of students enrolled in (attending) schools with specified NSLP measure outcomes, as well as disparities in NSLP measures based on school characteristics. RESULTS: Significantly more US secondary students attended schools with specified NSLP measures in 2013 than in 2011; increases were observed at both middle and high school levels. Increase rates for some NSLP measures were moderated by school characteristics; where this was the case, moderating associations decreased prior NSLP nutrition environment disparities that were especially evident in smaller schools and schools with higher percentages of minority students. CONCLUSION: Meaningful improvements have been made in the nutritional content of NSLP meals offered to US secondary students; these improvements have reduced prior NSLP meal disparities associated with school characteristics. Schools will need continued help with implementation and compliance monitoring in order to have the best opportunity to improve the nutrition environments for US students.