Depressive Symptoms in Adolescence and Young Adulthood.

Importance: Depressive symptoms have increased among US adolescents since 2010. It remains unclear as to what extent this increase will persist into young adulthood, potentially turning the youth mental health crisis into a young adult mental health crisis. Objective: To test the association between birth cohort and adolescent depressive symptoms at ages 18, 19 to 20, and 21 to 22 years and changes in these symptoms by cohort. Design, Setting, and Participants: This panel cohort study analyzed data from the Monitoring the Future longitudinal survey from 1990 to 2019, including birth cohorts from 1972 to 2001. Survey respondents were recruited from US high schools in 12th grade and were approximately aged 18 years (at baseline) through age 21 to 22 years (during mail and web follow-up). Data analysis was conducted from April to October 2023. Exposure: Depressive symptoms score (>12 vs ≤12, with >12 representing top-decile scores) on a scale examining affective items (eg, "Life often seems meaningless"). Main Outcomes and Measures: High (vs lower) depressive symptoms at ages 19 to 20 years and 21 to 22 years. Results: The 36 552 respondents included 18 597 females (50.5%), and most reported having a parent who graduated from college (44.8%). Among females, 19.1% (95% CI, 16.7%-21.4%) of the most recent birth cohort (born: 1997-2001) had high depressive symptoms at age 18 years, higher than any previous birth cohort. While prevalence declined by age 21 to 22 years, it remained higher than previous cohorts at that age. Among males, 13.4% (95% CI, 11.2%-15.6%) of the most recent birth cohort had high depressive symptoms at age 18 years, and prevalence increased through young adulthood. Males with high baseline depressive symptoms had 10.24 (95% CI, 7.01-14.97) times the odds of symptoms at age 19 to 20 years and 6.20 (95% CI, 3.93-9.78) times the odds of symptoms at age 21 to 22 years. Females with high baseline depressive symptoms had 9.16 (95% CI, 6.57-12.76) times the odds of symptoms at age 19 to 20 years and 7.28 (95% CI, 4.92-10.78) times the odds of symptoms at age 21 to 22 years. The magnitude of the associations did not vary over time. Population attributable fractions indicated that the total proportion of young adult symptoms associated with depressive symptoms at age 18 years among females has increased; in the most recent birth cohort, 55.25% (95% CI, 38.11%-65.13%) of depressive symptoms at age 21 to 22 years were associated with symptoms at age 18 years. Conclusions and Relevance: This panel cohort study found that increases in depressive symptoms in adolescence persisted into young adulthood, suggesting the need for primary prevention and mental health resources during the adolescent years.

Day-level correlates of nicotine and cannabis vaping among young adults in the United States.

Over the past two decades, vaping has increased in popularity among young adults. Yet, little is known about the daily activities or contexts associated with vaping behavior. The current study examined whether nicotine vaping, cannabis vaping, and dual-substance vaping (i.e., vaping both nicotine and cannabis) fluctuated in tandem with alcohol use and activities on a given day. Data came from the Monitoring the Future Vaping Supplement, a national sample of U.S. young adults. A subsample of people who vaped (N = 330 people) completed up to 14 daily surveys (N = 3686 days). Multilevel logistic regressions separated within- and between-person characteristics and controlled for combustible nicotine and cannabis use, day of the week, and demographic characteristics. Weights accounted for the complex survey design and attrition. Results demonstrated that nicotine vaping was more common on days when participants drank moderately or binge drank (compared to not drinking), used cigarettes, and spent more time at bars and parties than usual. Cannabis vaping on a given day was more likely on days when young adults drank moderately and spent more time at bars/parties. Likewise, moderate drinking, spending more time at bars/parties than usual, and spending less time on schoolwork than usual was associated with a higher likelihood of dual-substance vaping on a given day. Our findings highlight when young adults vape nicotine and cannabis, while also identifying proximal correlates of these behaviors to inform intervention and cessation efforts.

Simultaneous use of alcohol and cannabis and attenuated age-related declines in alcohol and cannabis use disorder symptoms across young adulthood.

Most young adults naturally mature out of high-risk substance use patterns, but it is important to identify factors that may impede normative declines. Use of alcohol and cannabis simultaneously (i.e., simultaneous alcohol and marijuana/cannabis [SAM]) is cross-sectionally associated with alcohol and cannabis concerns, and SAM use increases acute risks at the daily level. However, less is known about long-term risks of SAM use and, specifically, how SAM use relates to maturing out of alcohol and cannabis use. Using four consecutive years of survey data from young adults who reported SAM use (N=409; 1636 responses; aged 18-25 at baseline), we first estimated age-related changes in symptoms of alcohol and cannabis use disorder (AUD/CUD) using multilevel growth modeling. Findings supported a maturing out process, as both AUD and CUD symptom severity significantly declined across young adulthood, on average (4 % and 5 % per year respectively, with significant acceleration). Cross-level interactions tested whether participants' mean SAM use frequency across all four timepoints moderated age-related trajectories in AUD/CUD symptom severity. Significant interactions indicated that, relative to less-frequent SAM use, participants with more frequent SAM use showed less steep declines in AUD (1 % decrease per year vs. 6 % per year) and CUD symptoms (0 % decrease per year vs. 7 % per year); thus, SAM frequency was associated with slower/delayed maturing out of hazardous alcohol and cannabis use. Findings highlight that SAM use may be a correlate or risk-factor for prolonged high-risk substance use during young adulthood that relates to deviations from maturing out processes.

Planned and unplanned drinking to get drunk: A registered report examining willingness, drinking motives, and protective behavioral strategies using ecological momentary assessment.

OBJECTIVE: We examined alcohol use and consequences across five categories of same-day drinking intentions and willingness and tested whether same-day motives and protective strategies predicted differences in outcomes across categories of intentions and willingness. METHOD: In a 14-week ecological momentary assessment design, undergraduate student participants (N = 196) reported drinking intentions and behaviors over 13 surveys weekly (four morning surveys [Thursday through Sunday]; three midday, early, and late evening surveys [Thursday through Saturday]). On average, participants were 20.61 years old (SD = 1.50; range 17-25), 63% identified as female (n = 124), 29% as male (n = 57), and 8% identified as neither male nor female (n = 15; i.e., nonbinary; transgender; genderqueer; agender). Participants reported numbers of drinks consumed on the evening (past 2 hr) and morning (previous day) surveys. Multilevel generalized linear models tested effects of drinking intentions/willingness categories, motives, protective strategies, and interactions between key variables on alcohol use and consequences in several models. RESULTS: Rates and quantities of drinking were highest on planned drinking days, and especially high when students planned to get drunk. When enhancement and social motives were elevated, students were more likely to drink and consumed more drinks even on unplanned drinking days, and especially when socializing with others. Effects of coping motives were weaker and sparse. Harm reduction protective strategies were associated with more positive and negative consequences with little variation across planned and unplanned drinking days. CONCLUSION: Jointly considering drinking intentions and willingness narrows the intention-behavior gap in student drinking and suggests potential areas of focus for messaging around responsible drinking. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Initiation of high-intensity drinking and subsequent substance use in young adulthood.

High-intensity drinking (HID; 10+ drinks/occasion) is associated with acute and long-term risks, including use of other substances. Earlier HID initiation is associated with high-risk alcohol use in young adulthood. Less is known about when HID initiation occurs relative to other substances and how it is associated with subsequent substance use. This study examined survey data from 468 respondents (35.5% female, 65.5% non-Hispanic white) who reported initiating HID by age 20. Weighted descriptive statistics of year of initiation for HID, marijuana, and nicotine were obtained. Weighted linear and logistic regressions examined associations between year and order of HID initiation and age 20 substance use (i.e., nicotine vaping, cigarette use, other tobacco use, marijuana use, marijuana vaping, simultaneous alcohol and marijuana use, and other illicit drug use) and alcohol use disorder (AUD) symptoms. Over half of participants initiated HID after marijuana (54.6%) and nicotine (54.4%). Later HID initiation was associated with fewer AUD symptoms and lower odds of all outcomes except marijuana and other illicit drug use. Initiating HID before marijuana was associated with lower odds of marijuana use outcomes and other illicit drug use at age 20. Initiating HID before nicotine was associated with lower odds of all substance use outcomes at age 20. Earlier HID initiation was associated with risk for subsequent substance use, but initiating HID earlier than other substances was not. Given its association with both alcohol-related outcomes and other substance use in young adulthood, earlier HID initiation is an important target for screening and intervention.

Interaction Between State-Level Cigarette Prices and County-Level Tobacco 21 Coverage on Cigarette Smoking Outcomes Among US Adolescents.

PURPOSE: To examine whether Tobacco 21 (T21) law coverage moderated associations between cigarette prices and adolescent smoking and associated disparities. METHODS: We used nationally representative, repeated cross-sectional 2014-2020 Monitoring the Future study data (n = 20,547-96,083) to examine associations between state-level average cigarette price per pack and county-level T21 coverage (100% vs. < 100%) on past 30-day smoking participation, first and daily cigarette smoking initiation, and smoking intentions in US adolescents in eighth, 10th, and 12th grade. We implemented weighted, grade-stratified, modified Poisson regression models to test for interactions between price and T21 coverage for each outcome. We also tested for disparities by sex, race and ethnicity, parental education, and college educational expectations. RESULTS: Higher cigarette prices were associated with a lower probability of past 30-day smoking participation among eighth graders in counties with < 100% T21 coverage (average marginal effect = -0.003, 95% confidence interval = -0.006, 0.000) but not among eighth graders in counties with 100% T21 coverage (average marginal effect = 0.001, 95% confidence interval = -0.001, 0.004) (p for interaction = 0.005). There were no associations with other smoking outcomes or grades or evidence of differential associations by sociodemographic factors. DISCUSSION: Our findings suggested that higher cigarette prices were associated with lower adolescent smoking among eighth graders living in counties with < 100% T21 coverage. However, no such association was observed in other grades or smoking outcomes. Further investigation is necessary to determine the best combination of policies to reduce adolescent smoking, related sociodemographic disparities, and the use of other tobacco products in areas with fewer tobacco control policies.

Prevalence and correlates of daily-level reasons not to drink among young adults who use alcohol.

BACKGROUND: This study examined reasons not to drink in young adults in relation to demographics, alcohol use patterns, timing (weekend vs. weekday), and typical drinking motives. METHODS: Young adults who reported past 30-day alcohol use and at least one nondrinking day (n = 614; mean age = 21.5 years ±0.53) completed a survey of alcohol-related measures (e.g., typical drinking motives) and up to 14 daily surveys that included 12 reasons not to drink assessed on nondrinking days. Multilevel logistic regressions were estimated for each reason not to drink and related covariates. RESULTS: The most common reasons not to drink on a given day were "wasn't interested in drinking" (83.4% of nondrinking days) and "didn't want to get drunk" (81.8% of nondrinking days), with over 96% of participants endorsing each of these at least once. On days (11.6%; by 29.5% of participants) when another drug was used instead of alcohol, 81.8% used cannabis. Sex, race/ethnicity, weekend (vs. weekday), and drinking motives were differentially linked to reasons not to drink. Reporting high-intensity drinking (i.e., ≥10 drinking on a day) versus binge (5-9 drinks on a day) in the past 2 weeks was linked to "had a hangover recently" (odds ratio = 2.85) as a reason not to drink. CONCLUSIONS: Findings suggest that reasons not to drink reflect personal decisions and highlight ways to acknowledge situational barriers (e.g., saving money for food and essentials) that can be emphasized in brief interventions. Furthermore, reasons not to drink and alcohol motives may work in tandem within the motivational model to impact alcohol use behaviors.

First semester college experiences: Associations with substance use and mental health.

Introduction: Substance use (SU) and mental health (MH) concerns often occur as students transition from high school to college and may be associated with first semester experiences. Methods: Incoming first-year college students at a U.S., predominantly white, midwestern university were recruited for an intervention study. Participants reported on substance use, mental health, and college experiences at the end of their first semester of college (n = 781; 62.9 % female, mean age = 18.06 [SD = 0.24]; 77.2 % non-Hispanic white; 84.6 % heterosexual). Data for these current analyses were cross-sectional. Results: Identifying as Black, Indigenous, or another Person of Color, as a sexual minority, or as female was associated with more challenging first semester experiences. Social experiences that represent more social engagement were associated with greater substance use. College experiences reflecting an easier transition were associated with fewer mental health concerns. Alcohol use moderated the relation between academic challenges and mental health with stronger associations found at greater levels of alcohol use. Conclusions: First semester experiences were related to student mental health and substance use, suggesting the importance of early, targeted support for students to adjust to campus life.

Latent transition analysis of time-varying cannabis use motives to inform adaptive interventions.

OBJECTIVE: The rising prevalence of daily cannabis use among older adolescents and young adults in the United States has significant public health implications. As a result, more individuals may be seeking or in need of treatment for adverse outcomes (e.g., cannabis use disorder) arising from excessive cannabis use. Our objective was to explore the potential of self-reported motives for cannabis use as a foundation for developing adaptive interventions tailored to reduce cannabis consumption over time or in certain circumstances. We aimed to understand how transitions in these motives, which can be collected with varying frequencies (yearly, monthly, daily), predict the frequency and adverse outcomes of cannabis use. METHOD: We conducted secondary analyses on data collected at different frequencies from four studies: the Medical Cannabis Certification Cohort Study (n = 801, biannually), the Cannabis, Health, and Young Adults Project (n = 359, annually), the Monitoring the Future Panel Study (n = 7,851, biennially), and the Text Messaging Study (n = 87, daily). These studies collected time-varying motives for cannabis use and distal measures of cannabis use from adolescents, young adults, and adults. We applied latent transition analysis with random intercepts to analyze the data. RESULTS: We identified the types of transitions in latent motive classes that are predictive of adverse outcomes in the future, specifically transitions into or staying in classes characterized by multiple motives. CONCLUSIONS: The identification of such transitions has direct implications for the development of adaptive interventions designed to prevent adverse health outcomes related to cannabis use. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Reasons for alcohol use from 1976 to 2020 in the United States among individuals aged 18 to 30: Historical changes and mediation of cohort effects in binge drinking.

BACKGROUND: Alcohol use is declining among US adolescents/early young adults and increasing among other adults, with increases in adult binge drinking more concentrated in females than males. Reasons for drinking are historically patterned by age and sex, and if historically variant, could suggest that changes over time could in part explain age- and sex-differential cohort effects. METHODS: We analyzed longitudinal Monitoring the Future data for individuals born from 1958 to 1990. These individuals were aged 29/30 from 1987 to 2020, and first surveyed at age 18 from 1976 to 2008 (N = 14,190). Five reasons for drinking were analyzed (social, enhancement, avoid problems, relax, boredom). Drinking for social reasons and to relax were most prevalent. Total effects of birth cohort predicting past-2-week binge drinking were estimated with polynomial regression models by age; indirect effects through mediators were estimated. RESULTS: Drinking reasons exhibited dynamic time trends across birth cohort and sex. Notable increases were observed in social reasons: among women aged 29/30, social reasons increased from 53% to 87% from 1987 to 2020. Social reasons to drink had prominent positive indirect effects at adult ages (age 23/24 and above among men; age 19 and above among women), indicating that binge drinking would have increased less were it not for the increase in social reasons for drinking. Social reasons also mediated adult male/female differences, indicating that part of the reason sex differences are diminishing is the more rapid increases in social reasons for drinking among women. Indirect effects were also observed for drinking to relax and for boredom, and limited indirect effects were observed for enhancement and to avoid problems. CONCLUSION: Changing endorsement of drinking reasons, especially social reasons, among US adult drinkers mediate cohort effects in binge drinking in the US adult population and explain in part why binge drinking is converging by sex.

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.

Short-term changes in social role statuses across young adulthood and their relation to heavy drinking in a given month.

Young adulthood is a developmental period during which individuals experience shifts in their social roles in various domains, which coincides with a period of time that is also high risk for lifetime peaks in alcohol use. The current study examined age-related changes in heavy episodic drinking (HED) and high-intensity drinking (HID) and associations with short-term (i.e., monthly) variation in young adults' social roles over a 2.5-year period in a community sample of young adults who reported past-year alcohol use (N = 778, baseline age range 18-23). Results showed probabilities of past-month HED and HID changed in a nonlinear fashion across ages 18-26 with greater probabilities of use at younger ages. Most participants did not report being in the same social role status every sampled month, underscoring the presence of short-term role variation. Living with parents and being in a serious romantic relationship in a given month were negatively associated with past-month HED. Living with parents in a given month was also negatively associated with past-month HID. Being a 4-year college student and being employed full-time in a given month were not significantly related to either outcome. Findings provided partial evidence that monthly statuses were associated with heavy drinking. Several avenues for future research are described in light of the findings.

Morning cannabis use in young adults: Associations with overall levels of use, negative consequences, and cannabis use disorder symptoms across 2.5 years.

BACKGROUND: Emerging research suggests morning cannabis use may be associated with using more cannabis and experiencing more cannabis-related consequences. This paper examined whether months when young adults reported morning cannabis use (use between 6:00AM and 12:00PM) were associated with cannabis use frequency, negative cannabis-related consequences, and changes in cannabis use disorder (CUD) symptoms. METHODS: Participants were 778 young adults (Mage=21.11 years, 58.5% female) enrolled in a longitudinal study on substance use and social role transitions. Eligible participants were 18-23 years old at screening and reported past-year alcohol use. Participants completed a baseline survey, 24 consecutive monthly surveys, and a follow-up survey 30 months after baseline. Aims were tested using multilevel models and multiple regression. RESULTS: Analyses were limited to cannabis use months (N=4719; 28.9% of sampled months) and participants who reported cannabis use at least once (N=542; 69.7% of all participants). Morning use was reported in 12.3% of cannabis use months and at least once by 23.6% of participants who reported using cannabis. Relative to non-morning use months, morning use months were associated with greater cannabis use frequency and more negative consequences. However, the association between morning use and negative consequences was not statistically significant after controlling for cannabis use frequency. The percentage of cannabis use months with morning use was positively associated with increased CUD symptoms at the 30-month follow-up, relative to baseline. CONCLUSIONS: Morning cannabis use may be a useful marker of high-risk cannabis use and may contribute to the maintenance and worsening of CUD over time.

Historical Trends in Cannabis Use Among U.S. Adults Ages 19-55, 2013-2021.

OBJECTIVE: The current study used U.S. national data to examine trends in cannabis use from 2013 to 2021, focusing on changes in cannabis prevalence during young and middle adulthood and whether trends differed by sociodemographic characteristics. METHOD: Data from 2013 to 2021 from 21,182 respondents ages 19-30 and 29,871 ages 35-55 in the national Monitoring the Future panel study (followed since they were in 12th grade in 1976-2020) were used to model historical trends in cannabis prevalence (any 12-month use, any 30-day use, and near-daily use [≥20 occasions in the past 30 days]). RESULTS: Prevalence of 12-month, 30-day, and near-daily cannabis use significantly increased from 2013 to 2021 for both young and middle adults. Trends for all three behaviors indicated either consistent linear increases or two-slope increases in which the slope estimate was larger in more recent years. Historical increases in 12-month and 30-day use were similar for young and middle adulthood; the historical increase in near-daily use among middle adults had some evidence for a possible pandemic-related deviation. Historical trends did not differ by race/ethnicity or college degree. Trends for 12-month and 30-day use differed by sex, with women increasing more than men over time, especially during middle adulthood. CONCLUSIONS: Significant increases in the prevalence of cannabis use have occurred over the past decade for young and middle adults across sociodemographic groups, with some indication that near-daily use increased among middle adults at the onset of the pandemic. Although men continue to have a higher prevalence than women, the gap has narrowed, with greater increases in cannabis use among women.

Negative consequences associated with daily alcohol use as a nonlinear function of number of drinks in a daily diary study.

INTRODUCTION: Drinking intensity among young adults is associated with greater negative alcohol-related consequences, but often studied using categorical drinking thresholds. This study examined how alcohol-related consequences varied as a continuous function of number of drinks consumed, without imposing thresholds, to identify drink ranges for which risk is greatest. METHODS: Analyses included daily surveys from the Young Adult Daily Life study (2019-22) in which individuals reported drinking 1 or more alcoholic drinks (n=5219 days; 832 individuals). Time-varying effect models estimated total number of negative alcohol-related consequences and five individual consequences (hangover, drank more than planned, nausea/vomiting, did something embarrassing, blacked out) as a function of the number of drinks consumed among young adult males and females. RESULTS: Often, increases in the number and prevalence of negative consequences were a nonlinear function of the number of drinks consumed. Females reported few negative consequences on 1-to-3-drink occasions but steep increases in consequences on 4-to-9-drink occasions. Among females, the prevalence of blacking out increased six-fold from 4-drink (3.4%; 95% CI=2.6,4.7) to 9-drink occasions (20.6%; 95% CI=16.1,26.1). Among males, the prevalence of some consequences, while not linear, increased across the full drink range. Blacking out among males increased from 9.6% (95% CI=6.2,14.7) on 10-drink occasions to 23.9% (95% CI=15.0,35.8) on 15-drink occasions. CONCLUSIONS: Substantial heterogeneity is missed when typical drinking categories are used. In particular, variability in consequences across levels of the traditional binge drinking category suggests that important differences in risk may be missed when assessed as a uniform category.

Trends in coping reasons for marijuana use among U.S. adolescents from 2016 to 2022.

OBJECTIVE: This study examines historical trends in coping reasons for marijuana use among adolescents (1976-2022) and explores sociodemographic variations in recent years (2016-2022). METHOD: Data from U.S. national samples of 12th grade adolescents in the Monitoring the Future (MTF) study were used to examine long-term trends (1976-2022, N = 43,237) and recent differences by sociodemographic characteristics (2016-2022, N = 3,816). Measures included marijuana use, coping reasons for use, and sociodemographic characteristics. RESULTS: The most prevalent coping reason across time was "relax," endorsed by 52.9% of past 12-month users. Coping reasons mostly exhibited significant increases over time. Sociodemographic factors were associated with coping reasons. Females had higher odds of using marijuana to escape problems and get through the day (vs. males). Black respondents were more likely to use marijuana to get through the day, and Hispanic respondents were more likely to use to relax (vs. White respondents). Those with lower (vs. higher) parental education were more likely to use due to anger/frustration and to escape problems. Adolescents who used marijuana frequently (vs. less often) had higher odds of endorsing all coping reasons. There was no robust evidence of interactions between sociodemographic characteristics and year. CONCLUSIONS: Results indicate a consistent increase in coping reasons for adolescent marijuana use over time, with variations based on sociodemographic characteristics. The findings highlight the importance of understanding subpopulations of adolescents who have higher risk of coping-related marijuana use.

Predictors of morning cannabis use among young adults: Between- and within-person associations from 24 consecutive months of data.

Morning cannabis use is associated with heavier, frequent cannabis use and more cannabis-related negative consequences, yet little empirical research has examined its predictors. Using 24 months of longitudinal data, the present study tested demographic, psychosocial, and behavioral predictors of morning cannabis use among young adults at the monthly- and person-levels. Young adults (N = 778) were part of a larger study on substance use and social role transitions; participants completed a baseline survey and up to 24 consecutive monthly surveys. Hypotheses were tested using logistic multilevel models to estimate odds ratios for any vs. no morning use in a given month. At the monthly level, social anxiety motives and cannabis use frequency on a given month were positively associated with morning cannabis use. At the person level, typical coping motives, average cannabis use frequency, and male sex were positively associated with morning cannabis use. Findings advance our understanding of individual and psychosocial predictors of morning cannabis use among young adults. Notably, social anxiety motives may represent a malleable target for intervention efforts that could reduce risky use patterns associated with morning use. Such efforts may be especially prudent for young men, as our findings indicated morning cannabis use probabilities were much higher for men than women.

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.

Modified interactive Q-learning for attenuating the impact of model misspecification with treatment effect heterogeneity.

A sequential multiple assignment randomized trial, which incorporates multiple stages of randomization, is a popular approach for collecting data to inform personalized and adaptive treatments. There is an extensive literature on statistical methods to analyze data collected in sequential multiple assignment randomized trials and estimate the optimal dynamic treatment regime. Q-learning with linear regression is widely used for this purpose due to its ease of implementation. However, model misspecification is a common problem with this approach, and little attention has been given to the impact of model misspecification when treatment effects are heterogeneous across subjects. This article describes the integrative impact of two possible types of model misspecification related to treatment effect heterogeneity: omitted early-stage treatment effects in late-stage main effect model, and violated linearity assumption between pseudo-outcomes and predictors despite non-linearity arising from the optimization operation. The proposed method, aiming to deal with both types of misspecification concomitantly, builds interactive models into modified parametric Q-learning with Murphy's regret function. Simulations show that the proposed method is robust to both sources of model misspecification. The proposed method is applied to a two-stage sequential multiple assignment randomized trial with embedded tailoring aimed at reducing binge drinking in first-year college students.