Key Subgroup Differences in Age-Related Change From 18 to 55 in Alcohol and Marijuana Use: U.S. National Data

Patterns of substance use on a given day in a national sample of U.S. young adults

INTRODUCTION

Young adulthood constitutes a period of substance use risk and many young adults engage in use of more than one substance. While existing work has examined young adult co-use of substances at the day-level, there has not been a comprehensive investigation of day-level substance use that considers mode and intensity of use in a national sample of U.S. young adults.

METHODS

Individuals were eligible through participation in the nationally-representative Monitoring the Future study in 12th grade in 2018 and reporting past 30-day drinking in 12th-grade. Respondents completed a 14-day daily study in 2019 (n = 911 individuals; modal age 19). Days on which individuals reported alcohol, cannabis, and/or nicotine/tobacco use (n = 3,086 days and 590 individuals) were examined. Latent class analysis was used to identify patterns of substance use at the day-level with stress, boredom, loneliness, and type of day as covariates.

RESULTS

Six patterns of substance use days were identified: Vaping Nicotine (33.69 %), Cannabis Smoking (23.49 %), Alcohol Only (17.10 %), Cannabis Vaping (11.72 %), Multiple Combustibles (7.28 %), and Multimodal Cannabis (6.72 %) days. Stress and boredom were greater on Multimodal Cannabis days compared to most other substance use days. Alcohol Only days were characterized by lower levels of stress, boredom, and loneliness and a greater probability of being a special occasion or a weekend compared to other substance use days.

DISCUSSION

This study identified heterogeneous patterns of substance use behaviors among U.S. young adults. Understanding these patterns is important for developing intervention strategies that are responsive to specific substance use on a given day.

Age-Related Changes in Past-Month Alcohol, Cannabis, and Simultaneous Use in a Statewide Sample of Young Adults in Washington State

OBJECTIVE

It is unknown whether age-related decreases in substance use (maturing out) are observed in the legalized cannabis context. This study evaluated age-related changes in past-month alcohol use frequency, cannabis use frequency, and any simultaneous alcohol and marijuana/cannabis (SAM) use among young adults who engaged in the respective substance use behavior.

METHOD

Young adults residing in Washington State at enrollment (N = 6,509; 68.3% female; ages 18-25) provided 3-5 years of annual data in a longitudinal, cohort-sequential design from 2015 to 2019, a period after nonmedical cannabis was legalized and implemented. Multilevel growth models were conducted; poststratification weights were applied to make the sample more similar to the Washington young adult general population in demographic characteristics.

RESULTS

Among those who reported alcohol use at one or more time points, days of alcohol use increased from age 18 to approximately age 25 and then decreased until age 30. Among those who reported cannabis use at one or more time points, days of cannabis use increased from age 18 until approximately age 23 and then decreased until age 30. Among those who reported SAM use at one or more time points, the probability of SAM use increased from age 18 until approximately age 24 and then decreased until age 30. Age-related changes in SAM use were largely explained by concurrent changes in alcohol and cannabis use frequency.

CONCLUSIONS

Maturing out was observed for alcohol, cannabis, and SAM use among those who used each respective substance, with evidence that age-related changes in SAM use were tied to alcohol and cannabis use frequency.

Racial/Ethnic Heterogeneity in Parental Wealth and Substance Use from Adolescence to Young Adulthood

BACKGROUND

Substance use has a negative impact on health outcomes, at the individual and population levels. Little consensus exists regarding the relationship between socioeconomic position and substance use across race/ethnicity. This study examines how race/ethnicity and socioeconomic factors, especially parental wealth, are associated with substance use across an 18-year span from adolescence to young adulthood.

METHOD

Data were drawn from the National Longitudinal Survey of Youth 1997. Substance use behaviors were measured by self-reported heavy episodic drinking, daily cigarette smoking, and use of cannabis. Parental wealth and parental education were measured at baseline. Other socioeconomic factors included education, employment status, and household income. Two-level logistic regression was performed.

RESULTS

White respondents were more likely to drink, smoke cigarettes, and use cannabis compared to other racial/ethnic groups. More parental wealth was associated with greater odds of heavy episodic drinking, but lower odds of cigarette and cannabis usage. Race/ethnicity modifies the relationships between parental wealth and substance use. Whereas Black respondents from wealthier families had lower odds of heavy episodic drinking, the direction was opposite among white respondents. Wealth functioned as a protective factor against smoking for all groups, although to a lesser extent among respondents of color than for white respondents. Finally, wealthier Hispanics were more likely to smoke daily and use cannabis compared to other racial/ethnic groups.

CONCLUSION

These findings highlight a nuanced patterning of racial/ethnic heterogeneity in the relationship between parental wealth and substance use behaviors. Implications for policy and programming are discussed.

Latent Trajectories of Persistence of Cannabis Use Across Four Decades in 329 Men From the San Diego Prospective Study

OBJECTIVE

These analyses use data from a 40-year prospective study to extend information into the sixth and seventh decades of life regarding latent trajectory classes of cannabis use and predictors of those classes.

METHOD

Data from the San Diego Prospective Study were analyzed for 329 men of European and Hispanic ethnicity who had used cannabis at about age 23 at study entry (Time 1) and who were interviewed about every 5 years through about age 60 to 70. Latent classes of cannabis use trajectories were evaluated using latent class growth analyses, baseline predictors of class membership were determined, and significant predictors of each class were established using logistic regression analyses.

RESULTS

Four latent classes were identified ranging from 12.5% with cannabis use at every follow-up to 25.8% with no use after Time 1. Eight of 14 Time 1 predictors differed significantly across the trajectory classes, including five (age, marital status, religious identity, intensity of cannabis use, and sensation seeking) that significantly contributed to regression analyses when all significant predictors were considered together.

DISCUSSION

Forty-two percent of participants continued using cannabis long-term, including one in eight who used it at every follow-up. Predictors of continued use and identification of those most likely to stop required gathering information on a range of demographic, prior substance use, and personality characteristics.

CONCLUSIONS

Considering the potential enhanced dangers of cannabis use in later life, the high rate of continued use over four decades implies that clinicians should ask all older patients about recent cannabis use, especially if they had used it in their 20s.

Drinking patterns among US men and women: Racial and ethnic differences from adolescence to early midlife

BACKGROUND

Drinking patterns among young adult men and women in the United States have been understudied, especially among racial and ethnic groups such as Asian Americans and Hispanics. Because alcohol-related racial and ethnic health disparities persist or increase in midlife, identifying peak ages of hazardous drinking could help to reduce disparities.

METHODS

We used the National Longitudinal Study of Adolescent to Adult Health to examine: (1) past 12-month heavy episodic drinking (HED) and total alcohol volume consumption among non-Hispanic White (NHW), Black, Hispanic, and Asian men and women from ages 12 through 41, and (2) age-varying associations of race and ethnicity with drinking. Hispanic and Asian ethnic groups were disaggregated by historical drinking patterns. Time-varying effect models accounted for major demographic confounders.

RESULTS

NHW men and women experienced elevated drinking rates in their early 20s, with a second elevation in their 30s. Black men and women did not have elevated drinking until their 30s. Among Hispanic men and women, peak drinking periods varied by gender and subgroup drinking pattern. Peak HED and total consumption emerged in the early 30s for Asian men, while peak HED occurred in the early 20s for Asian women. Drinking at certain ages for some racial and ethnic minoritized men and women did not differ from that in their NHW counterparts.

CONCLUSIONS

Age periods during which subgroups in the U.S. population experience elevated alcohol consumption vary by ethnicity and gender. Recognition of these group differences could enhance our understanding of intervention timing.

Is the 21st birthday a turning point for alcohol and cannabis use? A monthly study of young adults

BACKGROUND

An important life-course event with respect to alcohol and cannabis use is turning 21 years of age, which may be associated with increases in use of these substances due to celebrations during the month and easier access to them on and following this birthday. We examined the trajectories of alcohol and cannabis use behaviors in the months leading up to, during, and following the 21st birthday month. We also examined whether the use trajectories vary by college status and baseline levels of use.

METHODS

We used data from 203 young adults recruited from the Greater Seattle region who turned 21 during the course of the study. Surveys were administered each month for 24 consecutive months. Measures included the typical number of drinks per week for the past month, the frequency of heavy episodic drinking, the number of cannabis use days, and any simultaneous alcohol and cannabis use. Multilevel spline models were run that estimated linear slopes over time at four intervals: (1) up to 1 month before the 21st birthday month; (2) from 1 month before to the month of the 21st birthday; (3) from the 21st birthday month to 1 month following; and (4) from 1 month following the 21st birthday month through all following months.

RESULTS

Alcohol use, generally, and simultaneous alcohol and cannabis use showed sharp increases from the month before the 21st birthday month to the 21st birthday month and decreases following the 21st birthday month. For cannabis use, there were significant increases in the months leading up to the 21st birthday and no other significant changes during other time intervals. Patterns differed by baseline substance use and college status.

CONCLUSIONS

Findings from the current study have implications for the timing and personalization of prevention and intervention efforts. Event-specific 21st birthday interventions may benefit from incorporating content targeting specific hazardous drinking behaviors in the month prior to the 21st birthday.

Profiles of alcohol and cannabis protective behavioral strategies use across two large, multi-site college student samples of concurrent alcohol and cannabis users

Concurrent use of alcohol and cannabis among college students is common and confers greater harms than the use of either of these substances alone. Large and growing bodies of literature have demonstrated the independent utility of behaviors used before, during, after, or instead of alcohol and cannabis use that minimize related harms (i.e., protective behavioral strategies [PBS]). However, little is known about the relationship between alcohol and cannabis PBS and their joint influence on harms among college students who concurrently use alcohol and cannabis. In the present study, we used data from two large, multi-site samples of college students, and restricted analyses to those who reported at least one episode of alcohol and cannabis use in the past 30 days (Study 1: N = 1104[Mage = 20.3, SD = 3.8; 70.0 % female; 79.5 % white]; Study 2: N = 2034[Mage = 20.2, SD = 3.2; 69.1 % female; 76.6 % white]). A latent profile analysis supported a 4-profile solution that was largely consistent across samples: Profile 1 (low alcohol/cannabis PBS; 8.8-11.9 %), Profile 2 (average alcohol/cannabis PBS; 33.1-37.7 %), Profile 3 (average alcohol PBS/low cannabis PBS; 16.3-25.2 %), and Profile 4 (high alcohol/cannabis PBS; 29.8-37.2 %). Profile 4 reported the least alcohol/cannabis use, fewest negative alcohol-/cannabis-related consequences, and lowest alcohol/cannabis use severity. In contrast, Profile 1 was the opposite for alcohol-related outcomes, and Profile 3 was the opposite for cannabis-related outcomes. These findings are preliminary but may suggest that targeting both alcohol and cannabis PBS in intervention is generally beneficial except some groups at risk for a particular substance may benefit from increased focus on that substance in intervention.

Daily-level simultaneous alcohol and marijuana use and its associations with alcohol use, marijuana use, and negative consequences in a young adult community sample

BACKGROUND

Simultaneous alcohol and marijuana (SAM) use has been associated with greater alcohol use and consequences at the daily level, but limited research has examined SAM use in relation to marijuana use and its consequences. This study tested daily associations between SAM use and four outcomes: alcohol use (number of drinks), marijuana use (hours high), negative alcohol consequences, and negative marijuana consequences.

METHODS

A community sample of young adults [ages 18-25, mean (SD) = 21.61 (2.17) years] with recent alcohol and SAM use was recruited (N = 409; 50.9% female; 48.2% non-Hispanic/Latinx White). Participants completed a baseline survey and six 2-week bursts of daily surveys (81.1% of morning surveys completed) and reported on substance use and negative substance-related consequences. Multilevel modeling was used to test the main aims and to explore each specific consequence.

RESULTS

Among days with any alcohol use, SAM use days were associated with consuming more drinks and experiencing more total negative alcohol-related consequences than non-SAM use days. Among days with any marijuana use, SAM use days were associated with more hours being high than non-SAM use days. Exploratory models showed that SAM use was related to five specific alcohol-related consequences and two specific marijuana-related consequences.

CONCLUSIONS

These findings build upon prior research by showing that SAM use days are linked to consuming more drinks, reporting more hours being high from marijuana, and experiencing more total alcohol-related consequences even after controlling for the number of drinks, the number of hours high, any tobacco/nicotine use, and any other substance use. SAM use was also associated with a greater likelihood of experiencing some specific consequences related to alcohol and marijuana. The findings underscore the need for additional research on SAM use and marijuana-related outcomes.

Age- and Sex-Varying Associations Between Depressive Symptoms and Substance Use from Modal Ages 35 to 55 in a National Sample of U.S. Adults

It is important to examine normative age-related change in substance use risk factors across the lifespan, with research focusing on middle adulthood particularly needed. The current study examined time-varying associations between depressive symptoms and alcohol, cigarette, and marijuana use from modal ages 35 to 55 in a national sample of US adults, overall and by sex. Data were obtained from 11,147 individuals in the longitudinal Monitoring the Future study. Participants were in 12th grade (modal age 18) in 1976-1982 and (for the data reported in this study) were surveyed again at modal ages 35 (in 1993-1999), 40, 45, 50, and 55 (in 2013-2019). Weighted time-varying effect modeling was used to examine age-related change in associations among depressive symptoms, any and heavy use of cigarettes, alcohol, and marijuana. Across midlife, greater depressive symptoms were associated with decreased odds of any alcohol use during the 40 s and 50 s, but with increased odds of binge drinking from ages 35-40, and-at most ages-any and pack + cigarette use and any and frequent marijuana use. The association between depressive symptoms and substance use was generally similar for men and women. Results highlight the increased risk for binge drinking, smoking, and marijuana with higher levels of depressive symptoms and underscore the importance of screening and interventions for depressive symptoms and substance use in midlife.

Alcohol Use Disorder Symptoms Reported during Midlife: Results from the Monitoring the Future Study among US Adults at Modal Ages 50, 55, and 60

BACKGROUND

The extent to which adolescent substance use is associated with alcohol use disorder (AUD) symptoms in midlife is not yet fully explored.

METHODS

Longitudinal data from the national Monitoring the Future study was used. The sample included 11,830 12th graders (1976-1987) who were surveyed again at modal ages 50 (37.8%), 55 (46.3%), or 60 (15.8%) in 2008-2019. Approximately 48.7% were male; 81.5% identified as non-Hispanic White. Weighted logistic and multinomial logistic regressions were used to examine associations between past 30-day use of cigarettes, marijuana, and alcohol at age 18, sociodemographics, and a midlife AUD symptom outcome (coded as non-drinking, drinking without AUD [endorsed ≤1 criterion], or AUD symptoms [endorsed 2+ criteria]).

RESULTS

Prevalence of midlife AUD symptoms was 27.1%. Higher relative risk of reporting AUD symptoms (vs. drinking without AUD) was associated with age 18 substance use (any cigarette use [vs. no use], any marijuana use [vs. no use], binge drinking [vs. both no use and drinking at less than binge levels]), being male (vs. female), being non-Hispanic White (vs. non-Hispanic Black), and having a 4-year college degree. Higher relative risk of reporting non-drinking (vs. drinking without AUD) was associated with no 30-day alcohol use at age 18, being non-Hispanic Black or non-Hispanic other (vs. non-Hispanic White), and not having a 4-year college degree.

CONCLUSIONS

Findings suggest substance use at age 18 has meaningful associations with midlife AUD symptoms. Dissemination of prevention and intervention efforts in adolescence and early adulthood may be important for reducing hazardous midlife drinking.

Impacts of recreational cannabis legalization on cannabis use: a longitudinal discordant twin study

AIMS

To estimate the effect of recreational legalization on cannabis use frequency and sources of variance across legal environments.

DESIGN

Longitudinal discordant twin and gene-environment interaction models in twins recruited from birth records and assessed prospectively.

SETTING

The United States, including states with different recreational cannabis policies before and after 2014, when recreational cannabis was first legalized.

PARTICIPANTS

Two longitudinal, prospectively assessed samples of American twins aged 24-47 (n = 1425 in legal states, n = 1996 in illegal states), including 111 monozygotic pairs discordant for residence.

MEASUREMENTS

Current cannabis use frequency (measured continuously and ordinally) was the primary outcome, and the predictor was recreational status of cannabis (legal/illegal) in the participant's state of residence at the time of assessment. Covariates include age, sex and cannabis use frequency prior to 2014.

FINDINGS

Accounting for pre-2014 use, residents of legal states used cannabis more frequently than residents of illegal states (b = 0.21, P = 8.08 × 10-5 ). Comparing 111 pairs of monozygotic twins discordant for residence confirmed the effect (b = 0.18, P = 0.014). There was inconclusive evidence for genetic influences on cannabis use frequency that were specific to the legal environment [χ2  = 2.9 × 10-9 , degrees of freedom (d.f.) = 1, P > 0.999]. Existing genetic influences were moderated by the legal environment, as the genetic correlation between marijuana use before and after legalization was lower in states that legalized (rgenetic  = 0.24) compared with states that did not (rgenetic  = 0.78, Pdifference  = 0.016).

CONCLUSIONS

In the United States, there appears to be a ~ 20% average increase in cannabis use frequency attributable to recreational legalization, consistent across increasingly rigorous designs. In addition, the heritability of cannabis use frequency appears to be moderated by legalization.

An empirical evaluation of alternative approaches to adjusting for attrition when analyzing longitudinal survey data on young adults' substance use trajectories

OBJECTIVES

Longitudinal survey data allow for the estimation of developmental trajectories of substance use from adolescence to young adulthood, but these estimates may be subject to attrition bias. Moreover, there is a lack of consensus regarding the most effective statistical methodology to adjust for sample selection and attrition bias when estimating these trajectories. Our objective is to develop specific recommendations regarding adjustment approaches for attrition in longitudinal surveys in practice.

METHODS

Analyzing data from the national U.S. Monitoring the Future panel study following four cohorts of individuals from modal ages 18 to 29/30, we systematically compare alternative approaches to analyzing longitudinal data with a wide range of substance use outcomes, and examine the sensitivity of inferences regarding substance use prevalence and trajectories as a function of college attendance to the approach used.

RESULTS

Our results show that analyzing all available observations in each wave, while simultaneously accounting for the correlations among repeated observations, sample selection, and attrition, is the most effective approach. The adjustment effects are pronounced in wave-specific descriptive estimates but generally modest in covariate-adjusted trajectory modeling.

CONCLUSIONS

The adjustments can refine the precision, and, to some extent, the implications of our findings regarding young adult substance use trajectories.

Individual-, peer-, and parent-level substance use-related factors among 9- and 10-year-olds from the ABCD Study: Prevalence rates and sociodemographic differences

Background

Although a relatively large body of research has identified multiple factors associated with adolescent substance use, less is known about earlier substance-related factors during preadolescence, including curiosity to use substances. The present study examined individual-, peer-, and parent-level domains pertaining to substance use and how these domains vary by sociodemographic subgroups and substance type.

Methods

Participants were 11,864 9- and 10-year-olds from the baseline sample of the Adolescent Brain Cognitive Development (ABCD) Study. Youth-reported measures were curiosity to use substances and perceived peer substance use. Parent-reported measures were availability of and rules about substances. Generalized logistic mixed models (GLMM) were used to compare these measures across alcohol, nicotine, and marijuana and across sociodemographic subgroupings (sex, race/ethnicity, household income, and family history of alcohol problems). GLMM was then used to examine predictors of curiosity to use by substance type.

Results

The most striking descriptive differences were found between race/ethnicity and income categories (e.g., positive associations between greater income and greater availability of alcohol). In multivariable analyses, greater curiosity to use alcohol was associated with being male, higher household income, perceived peer alcohol use, and easy alcohol availability; greater curiosity to use nicotine was associated with being male, perceived peer cigarette use, easy availability of cigarettes, and no parental rules about cigarette use.

Conclusions

This study identified substance use-related individual-, peer-, and parent-level factors among a diverse, national sample. Findings highlight the importance of considering sociodemographic and substance-specific variability and may help identify risk and protective factors preceding adolescent substance use.

Structural sexism and Women's alcohol use in the United States, 1988-2016

BACKGROUND

Women's alcohol consumption and binge drinking have increased concurrent with socio-economic gains and may be related to structural sexism.

METHODS

We examined associations between structural sexism (state-level sex inequality in political/economic status), and alcohol outcomes among women in Monitoring the Future (N = 20,859) from 1988 to 2016 (ages 27-45 in 2016). We controlled for state and individual confounders and tested three mediators: depressive symptoms, restrictive alcohol norms, and college completion.

RESULTS

Increased structural sexism was associated with decreased alcohol consumption frequency (RR: 0.974, 95% CI: 0.971, 0.976) and binge drinking probability (OR: 0.917, 95% CI: 0.909, 0.926). Norms and education but not depressive symptoms partially mediated these relationships.

CONCLUSION

Among women in the midlife in recent years, lower levels of state structural sexism were associated with greater alcohol consumption and binge drinking. These findings suggest that as states become more gender-equal-which confer numerous benefits for women's rights and health-additional resources and messaging may be required to prevent harmful alcohol use among women.

Developmental and etiological patterns of substance use from adolescence to middle age: A longitudinal twin study

BACKGROUND

The common liability to addiction framework suggests the tendency to use substances is largely a general heritable liability, but little is known about how expression of liability varies across development. We evaluated average developmental trajectories and covariation underlying commonly used substances using a genetically informative prospective design spanning three decades.

METHODS

Using a sample of 3762 twins across seven waves of assessment spanning ages 14-40, we modeled these relationships using two complementary approaches: piecewise latent growth and common factor modeling on four measures of alcohol, tobacco, and marijuana use RESULTS: Average use increased across adolescence and either stabilized (alcohol frequency) or declined (all others) in adulthood. Trajectories were heritable (~.35-.75), and genetically correlated with one another (~.40-.80). The random intercepts, centered at age 16, exhibited shared environmental correlations across substances. We found moderate to large phenotypic (rp~.3-.9) and genetic correlations (rg~.3-1) among the longitudinally varying common factors loading on use of each substance at each age. The factor loadings declined with age, reflecting waning influence of common etiology in substance use.

CONCLUSIONS

Trajectories of substance use were strongly correlated with each other and influenced primarily by genetic and non-shared environment. A heritable common factor accounted for co-occurring substance use from mid-adolescence to mid-adulthood, and greater substance specificity emerged with maturation. These results extend and reinforce prior work examining consumption and problem use, providing new evidence over a broad age range showing that substance use behaviors are influenced by a more general liability in adolescence and specificity increases across development.