A pilot trial of a brief intervention for cannabis use supplemented with a substance-free activity session or relaxation training

OBJECTIVE

Cannabis use is increasing among college students and commonly co-occurs with anxiety symptoms in this age group. Interventions that reduce anxiety may also reduce cannabis use. Behavioral economic theory suggests that substance use reductions are most likely when there is an increase in substance-free reinforcement. This randomized pilot trial evaluated the efficacy of a brief motivational intervention (BMI) for cannabis supplemented by either a substance-free activity session (SFAS) or a relaxation training (RT) session for reducing cannabis use, problems, craving, and anxiety symptoms.

METHOD

One hundred thirty-two college students (Mage = 19.9; 54% female; 67% White, 31% Black) who reported five or more past-month cannabis use days were randomized to: (a) assessment-only (AO); (b) BMI plus SFAS; or (c) BMI plus RT. Participants in the BMI conditions received two individual counselor-administered sessions plus a brief phone booster session. Outcomes were evaluated 1- and 6-months postintervention.

RESULTS

Relative to assessment, both BMI + SFAS and BMI + RT were associated with significant reductions in cannabis problems and craving at 1-month follow-up, and significant reductions in anxiety at 6-month follow-up. Relative to AO, BMI + RT was associated with significant reductions in cannabis use at 1-month follow-up. There were no differences between BMI conditions.

CONCLUSIONS

This pilot trial was not adequately powered to conclusively evaluate relative efficacy but provides preliminary support for the short-term efficacy of both two-session interventions for reducing anxiety and cannabis-related risk among nontreatment seeking emerging adults. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Dose-dependent Relationships of Same-day and Typical Substance Use to Sleep Duration in College Cannabis and Alcohol Users: A Multilevel Modeling Approach Using Daily Diary Data

This study characterized how quantities of cannabis and alcohol use affect sleep. Single-day and typical cannabis and alcohol use patterns were considered to assess acute-chronic use interactions. Linear and non-linear associations assessed dose-dependence. College students (n=337; 52% female) provided 11,417 days of data, with up to five time points per day. Daily self-reported sleep duration, cannabis use quantity, and alcohol use quantity were subjected to linear mixed modeling to capture linear and curvilinear associations between single-day and typical use on same-night and typical sleep. Sleep duration (difference between bedtime and waketime) was the outcome. Quantity of cannabis used each day andtypical quantity used across all days were predictors in the cannabis models. Parallel single-day and typical alcohol variables were predictors in the alcohol models. Follow-up analyses excluded days with alcohol-cannabis co-use. Main effects of single-day and typical cannabis quantity on sleep duration were observed when all cannabis-use days were modeled. Higher than typical doses of single-day and typical cannabis were associated with longer sleep durations, but only to a point; at the highest doses, cannabis shortened sleep. A main effect of single-day alcohol quantity and two interactions (single-day use with both linear and curvilinear typical use) on sleep duration were observed when all alcohol-use days were modeled. Greater alcohol consumption on a given day led to shorter same-night sleep, but typically heavier drinkers required higher doses than typically lighter drinkers to experience these adverse effects. Follow-up models suggested alcohol co-use may contribute to the purported sleep-promoting effects of cannabis.

Associations of daily alcohol, cannabis, combustible tobacco, and e-cigarette use with same-day co-use and poly-use of the other substances

BACKGROUND

Young adults frequently use alcohol, cannabis, and tobacco together. Given the increased prevalence of e-cigarette use and recreational cannabis use, we investigated daily patterns of alcohol, cannabis, and tobacco use and distinguished combustible tobacco from e-cigarettes.

METHODS

Young adult college students (N=341) reporting past-month alcohol and cannabis use "at the same time so that their effects overlapped" completed two 28-day bursts of repeated daily surveys. Exposures were day- and person-level use of each substance. Outcomes were (1) same-day co-use of each remaining substance or (2) poly-use of the other substances.

RESULTS

Daily use of alcohol, cannabis, combustible cigarettes, and e-cigarettes increased the odds of same-day co-use of the other substances (except combustible tobacco with e-cigarettes) and each poly-use outcome. The influence of person-level substance use on daily substance use was less consistent. Only e-cigarette use increased the odds of daily alcohol use. Use of either tobacco product but not alcohol increased the odds of daily cannabis use. Person-level alcohol and cannabis use increased the odds of daily use of either tobacco product but use of one tobacco product was not associated with daily use of the other product.

CONCLUSIONS

These findings increase our understanding of emerging daily patterns of alcohol, cannabis, and tobacco co-use, and the impact of different tobacco products. Future work is needed to extend this research into non-college samples and people who use tobacco but do not use alcohol and cannabis simultaneously, and examine daily chronologies of multiple substances that could serve as dynamic markers of risk.

Acute Consequences Associated With Co-use of Alcohol and Cannabis: A Daily Survey Analysis

OBJECTIVE

Co-use of alcohol and cannabis has been associated with more total negative consequences than single-substance use, but results have been mixed depending on whether the single substance was alcohol or cannabis. The present study used within-person analyses to examine whether co-use increased the risk for experiencing specific acute negative consequences.

METHOD

College students who were co-users of alcohol and cannabis (N = 341; M age = 19.8 years; 51.3% female; 74.8% White) completed 56 days of five daily surveys across two bursts. We used generalized linear mixed effects models to examine the effects of type of substance use day on specific negative consequences, controlling for consumption and covariates.

RESULTS

Relative to both alcohol-only and co-use days, cannabis-only days were associated with decreased likelihood of experiencing hangover, blackout, nausea/vomiting, injury, rude/aggressive behavior, and unwanted sex. Relative to alcohol-only days, cannabis-only and co-use days were associated with an increased likelihood of driving high/drunk. Finally, there was an increased likelihood of hangovers on alcohol-only days compared with co-use days.

CONCLUSIONS

Days with different types of substance use differed in specific consequences. Most of the negative co-use consequences investigated here appear to be driven by alcohol consumption rather than cannabis use. The results also indicated that these young adults were more likely to endorse driving under the influence of cannabis than alcohol. Interventions for co-use should target alcohol consumption to reduce negative consequences such as blackout, injury, rude/aggressive behavior, and unwanted sex and highlight the dangers of driving under the influence of cannabis.

Does abstaining from alcohol in high school moderate intervention effects for college students? Implications for tiered intervention strategies

Brief motivational intervention (BMI) and personalized feedback intervention (PFI) are individual-focused brief alcohol intervention approaches that have been proven efficacious for reducing alcohol use among college students and young adults. Although the efficacy of these two intervention approaches has been well established, little is known about the factors that may modify their effects on alcohol outcomes. In particular, high school drinking may be a risk factor for continued and heightened use of alcohol in college, and thus may influence the outcomes of BMI and PFI. The purpose of this study was to investigate whether high school drinking was associated with different intervention outcomes among students who received PFI compared to those who received BMI. We conducted moderation analyses examining 348 mandated students (60.1% male; 73.3% White; and 61.5% first-year student) who were randomly assigned to either a BMI or a PFI and whose alcohol consumption was assessed at 4-month and 15-month follow-ups. Results from marginalized zero-inflated Poisson models showed that high school drinking moderated the effects of PFI and BMI at the 4-month follow-up but not at the 15-month follow-up. Specifically, students who reported no drinking in their senior year of high school consumed a 49% higher mean number of drinks after receiving BMI than PFI at the 4-month follow-up. The results suggest that alcohol consumption in high school may be informative when screening and allocating students to appropriate alcohol interventions to meet their different needs.

The role of alcohol and cannabis co-use in drinking rate and its impact on consequences

BACKGROUND

The impact of alcohol and cannabis co-use on college student drinking and related outcomes is complex. Specific characteristics or patterns of co-use events beyond drinking quantity may be important to the experience of consequences. The present study used repeated daily surveys to examine the association between co-use (versus use of alcohol only) and drinking rate on negative consequences.

METHODS

The sample included 318 college students (M_age  = 19.8, 47% female, 76% non-Hispanic White) who were co-users of alcohol and cannabis, recruited from three U.S. college campuses. Participants completed 56 days of data collection (number of drinking days ranged from 1 to 38). Two measures of drinking rate were examined: (1) daily rate (number of drinks divided by number of hours spent drinking per day); and (2) peak hour rate (maximum number of drinks consumed in a single hour) to account for anomalous drinking days of long duration. Generalized linear mixed models examined: (1) associations of co-use with peak hour rate (model 1a) and daily rate (model 1b); (2) associations of peak hour rate (model 2a) and daily rate (model 2b) with experiencing any negative consequence; and (3) interactions of co-use with peak hour rate (model 3a) and daily rate (model 3b) on experiencing a consequence.

RESULTS

Co-use was positively associated with peak hour rate but not daily rate. Both peak hour and daily rate positively predicted likelihood of experiencing a negative consequence. The interaction of both peak hour and daily rate by co-use was significant such that the association of rate with experiencing a consequence was stronger on alcohol-only days compared to co-use days.

CONCLUSIONS

Daily drinking rate and peak hour drinking rate are unique and should be considered when discussing drinking patterns. Both predict negative consequences and may be important aspects of interventions for negative drinking-related outcomes among college students.

Nuanced relations between simultaneous alcohol and cannabis use motives and negative consequences among college students: The role of multiple product use

Simultaneous alcohol and marijuana (SAM) use is common, but it exacerbates negative consequences. Individuals use alcohol and cannabis products in different ways and have distinct reasons for use. The present study examines day-level effects of motives on consequences on SAM-use days, accounting for consumption, and tests whether using multiple alcohol (e.g., beer + liquor) and/or cannabis (e.g., concentrate + leaf) products on the same day mediates these relations. College students engaging in SAM use at least once in the past month (N = 281; Mage = 20.17) completed two bursts of 28 consecutive days of data collection. We examined within-person effects of motives (effect-enhancement, social, offered [it was offered], coping) on number of negative consequences and on experiencing hangover, nausea, or blackout; and indirect effects via two concurrent mediators: using multiple alcohol products and multiple cannabis products. Total effect models showed effect-enhancement motives were related to nausea, social motives to number of total consequences and hangover, and coping motives to blackout. Effect-enhancement, social, and offered motives evinced significant indirect effects on consequence outcomes via multiple alcohol, but not cannabis, product use. Coping motives did not exhibit significant indirect effects, and were related to multiple cannabis, but not alcohol, product use, although all other motives were related to both mediators. Findings support recent work demonstrating within-person relations between social motives and negative consequences on SAM-use days. Limiting the number of alcohol products consumed on SAM-use days may be beneficial, particularly for young adults using to enhance intoxication or for social reasons. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Substance-Specific Risk Factors among Young Adults: Potential Prevention Targets across Cannabis-Permissive Environments

PURPOSE

This study examined levels of substance-specific risk factors such as perception of harm from substance use among young adults in a range of cannabis-permissive environments. The main objective was to inform future preventive interventions aimed at reducing cannabis use in the context of increasingly permissive environments.

METHODS

Data came from the Community Youth Development Study (CYDS) collected in 2016 when participants were about 23 years old (n = 1,722 participants residing in 46 U.S. states). Young adults self-reported their perceptions about the harms related to cannabis, alcohol, and cigarette use; attitudes about and ease of access to cannabis and other substances; and perceived wrongfulness and social acceptability of cannabis, alcohol, and cigarette use and of selling of cannabis and other illegal drugs.

RESULTS

Young adults in more permissive cannabis contexts reported higher levels of all cannabis-specific risk factors (e.g., greater access to and more favorable attitudes about cannabis use), except for perception of harm from regular cannabis use. However, permissiveness of the cannabis environment was not associated with heightened levels of risk factors for other substance use (such as alcohol, cigarettes, and opioids).

CONCLUSIONS

Future preventive interventions for young adults living in more permissive cannabis contexts may need to focus on cannabis-specific risk factors in particular and go beyond considerations of harm from regular use. Future studies should replicate these findings with other samples.

Motives, Frequency, and Consequences of Cannabis Use Among College Students

We investigated profiles of cannabis use motives among current cannabis-consuming college students. Then we assessed profile differences in demographic characteristics, social contexts of use, regulatory environment, alcohol use, negative affect, negative consequences, and cannabis use. Participants ( N = 1, 213) were from three universities in states with different cannabis legislation. Six profiles emerged: Low Motives, Low to Moderate Enhance, High Enhance, High Enhance & Social + Moderate Expand, High Enhance & Cope, and High Motives. Profiles differed in social contexts of use, sex, alcohol use, negative affect, and regulatory environment. Profiles endorsing high and multiple motives had higher cannabis use and negative consequences, relative to profiles with low or fewer motives. Profiles characterized by high avoidance motives (i.e., coping) had the highest cannabis use and consequences. Interventions targeting types and intensity of motives for cannabis-use may help reduce use and related consequences among college students who use cannabis.

Understanding Heterogeneity Among Simultaneous Alcohol and Marijuana Users: Latent Classes Derived From Daily Diary Data

OBJECTIVE

Simultaneous use of alcohol and marijuana (SAM) is common among U.S. college students, but little research has examined specific substance use behaviors during SAM use episodes. This study identified latent classes of SAM users based on their SAM, alcohol-only, and marijuana-only use episodes.

METHOD

College student SAM users (N = 284; 50.7% female; M age = 19.8 years) completed up to five surveys each day across two 4-week bursts. Latent class analysis (LCA) was used to characterize SAM users based on seven latent class indicators of use behavior. Sex was examined in relation to latent class membership.

RESULTS

Five unique classes emerged: Frequent Marijuana-Focused SAM users (21%); Frequent Alcohol-Initiating SAM users (29%); Heavy-Drinking Infrequent SAM users (12%); Moderate SAM users (29%); and Light Infrequent SAM users (9%). These groups were differentiated primarily by their frequency of SAM use, form of marijuana, whether marijuana was used on non-SAM occasions, and whether consequences were experienced. Groups differed significantly by sex.

CONCLUSIONS

College student SAM users are heterogeneous with respect not only to their degree of SAM use but also in their pattern of drinking, type of marijuana use, relative focus on alcohol versus marijuana, and risk of experiencing acute negative consequences. Describing this heterogeneity is an important step toward developing interventions for different types of users.

Unplanned versus planned simultaneous alcohol and cannabis use in the daily lives of a predominantly white college student sample: What are the motives, contexts, and outcomes?

OBJECTIVE

Simultaneous alcohol and cannabis use is common among college students and associated with more consumption and consequences compared to single-substance use. This study examined occasions of simultaneous use and compared planned occasions to unplanned occasions with respect to motives, contexts, consumption, and consequences.

METHOD

College student simultaneous users (N = 341; 53% women; 74% White) completed five daily surveys for 54 days. Mixed-effects models examined motives and contexts of simultaneous use occasions as a function of whether alcohol and cannabis use were (a) both planned versus (b) unplanned, no use planned, or (c) unplanned, single-substance use planned and whether alcohol and cannabis consumption and negative simultaneous use-related consequences varied across planned versus unplanned occasions.

RESULTS

Social and enhancement motives were related to planned simultaneous use; offered and coping motives were associated with planned single-substance use that became simultaneous use (vs. planned simultaneous use). Compared to unplanned use, planned simultaneous use was negatively associated with using at home or alone, and positively associated with using with others, more intoxicated people, and more people using cannabis. Planned simultaneous use was associated with more alcohol and cannabis consumption. No significant differences were found for negative consequences.

CONCLUSIONS

Planned simultaneous use was motivated by social and enhancement reasons, whereas planned single-substance use that became simultaneous use was more likely motivated by offers or for coping. Planned simultaneous use resulted in greater consumption, but not negative consequences. Results provide specific motives and contexts associated with unplanned and planned simultaneous use to be incorporated into real-time interventions. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Understanding Heterogeneity Among Simultaneous Alcohol and Marijuana Users: Latent Classes Derived From Daily Diary Data

OBJECTIVE

Simultaneous use of alcohol and marijuana (SAM) is common among U.S. college students, but little research has examined specific substance use behaviors during SAM use episodes. This study identified latent classes of SAM users based on their SAM, alcohol-only, and marijuana-only use episodes.

METHOD

College student SAM users (N = 284; 50.7% female; M age = 19.8 years) completed up to five surveys each day across two 4-week bursts. Latent class analysis (LCA) was used to characterize SAM users based on seven latent class indicators of use behavior. Sex was examined in relation to latent class membership.

RESULTS

Five unique classes emerged: Frequent Marijuana-Focused SAM users (21%); Frequent Alcohol-Initiating SAM users (29%); Heavy-Drinking Infrequent SAM users (12%); Moderate SAM users (29%); and Light Infrequent SAM users (9%). These groups were differentiated primarily by their frequency of SAM use, form of marijuana, whether marijuana was used on non-SAM occasions, and whether consequences were experienced. Groups differed significantly by sex.

CONCLUSIONS

College student SAM users are heterogeneous with respect not only to their degree of SAM use but also in their pattern of drinking, type of marijuana use, relative focus on alcohol versus marijuana, and risk of experiencing acute negative consequences. Describing this heterogeneity is an important step toward developing interventions for different types of users.

Changes in Cannabis Consumption Among College Students During COVID-19

OBJECTIVE

College campuses closed in March 2020 because of the COVID-19 pandemic, disrupting the lives of students. The goal of the present study was to examine whether cannabis use changed from before campus departures prompted by COVID-19 to after campus departures and after the semester ended--and if living situation explained observed changes. We also examined changes in specific formulations of cannabis and self-reported reasons for perceived changes in use frequency.

METHOD

A sample of 223 college student cannabis users (61% female) from three universities completed two online surveys (one in May 2020 assessing cannabis use pre-campus closure [pre-closure] and since campus closed [post-closure-1], and another in September 2020 assessing cannabis use since remote classes ended [post-closure-2]).

RESULTS

Any use of cannabis and use of each specific formulation (leaf, edibles, concentrates) declined from pre-closure to post-closure-1, whereas the frequency of use did not change. Any cannabis use declined for those who stayed living dependently or moved to dependent living. Leaf use declined for all groups, concentrate use declined only for those who moved from independent to dependent living, and edible use declined only for those who stayed living dependently or moved to dependent living. Cannabis use did not change between post-closure-1 and post-closure-2, regardless of living situation stability or transition.

CONCLUSIONS

Overall, among a sample of cannabis-using college students, the prevalence of any cannabis use, but not frequency of use, was reduced during the pandemic. Living with parents appears to be protective against frequent cannabis use.

Changes in Cannabis Consumption Among College Students During COVID-19

OBJECTIVE

College campuses closed in March 2020 because of the COVID-19 pandemic, disrupting the lives of students. The goal of the present study was to examine whether cannabis use changed from before campus departures prompted by COVID-19 to after campus departures and after the semester ended--and if living situation explained observed changes. We also examined changes in specific formulations of cannabis and self-reported reasons for perceived changes in use frequency.

METHOD

A sample of 223 college student cannabis users (61% female) from three universities completed two online surveys (one in May 2020 assessing cannabis use pre-campus closure [pre-closure] and since campus closed [post-closure-1], and another in September 2020 assessing cannabis use since remote classes ended [post-closure-2]).

RESULTS

Any use of cannabis and use of each specific formulation (leaf, edibles, concentrates) declined from pre-closure to post-closure-1, whereas the frequency of use did not change. Any cannabis use declined for those who stayed living dependently or moved to dependent living. Leaf use declined for all groups, concentrate use declined only for those who moved from independent to dependent living, and edible use declined only for those who stayed living dependently or moved to dependent living. Cannabis use did not change between post-closure-1 and post-closure-2, regardless of living situation stability or transition.

CONCLUSIONS

Overall, among a sample of cannabis-using college students, the prevalence of any cannabis use, but not frequency of use, was reduced during the pandemic. Living with parents appears to be protective against frequent cannabis use.

Forgoing plans for alcohol and cannabis use in daily life: Examining reasons for nonuse when use was planned in a predominantly white college student sample

BACKGROUND

The reasons for college students to abstain from alcohol and cannabis use on a given day can inform efforts to prevent or intervene in those behaviors. Research on reasons for alcohol nonuse remains in its nascent stages and no study to date has examined reasons for cannabis nonuse on a given day. Here we examine reasons for nonuse among college students after they planned to use alcohol and/or cannabis.

METHODS

College students (N = 341; M_age  = 19.79; 53% women; 74% White) from 3 universities completed 54 days of data collection across which approximately 50% were nonuse days. Each morning, participants indicated whether they planned to use that day; nonuse reasons were assessed the next morning, if applicable. Generalized linear mixed-effects models were used to disentangle within- and between-person effects.

RESULTS

On a given nonuse day (at the within-person level), "work" and "school" were reasons associated with having no plan to use alcohol and "to feel in control" was linked to having no plan to use cannabis. "Did not want to get high" was related to forgoing plans (did not use when originally planned) for alcohol use at the within-person level. At the between-person level, "no desire" was associated with no plans for alcohol or cannabis use and "did not want to get high" was related to no plans for cannabis use. "School" and "could not get" were related to forgoing plans for alcohol and cannabis use, respectively, at the between-person level.

CONCLUSION

An examination of earlier intentions for alcohol and/or cannabis use on nonuse days yielded novel findings on the intention-behavior gap. Reasons for nonuse can inform intervention and prevention strategies (e.g., those involving social norms or just-in-time adaptive efforts) for alcohol and cannabis use on college campuses.

More Reasons, More Use and Problems? Examining the Influence of Number of Motives on Consumption and Consequences Across Alcohol-Only, Cannabis-Only, and Simultaneous-Use Days

OBJECTIVE

Alcohol and cannabis use as well as their simultaneous use are common among U.S. college students. Reasons for use are proximal predictors of consumption and consequences. Little research has examined possible adverse effects of endorsing multiple motives on a given use day. We examined the effects of the number of motives on consumption and negative consequences for alcohol-only, cannabis-only, and simultaneous-use days.

METHOD

College students (N = 341; 53% women; mean age = 19.79 years) who reported past-month simultaneous alcohol and cannabis use completed 54 days of data collection. We used generalized linear mixed-effects models to examine the effects of endorsing multiple motives on consumption and consequences.

RESULTS

Across models, endorsing more motives than typical on a given use day (within person) and more motives in general (between person) was related to greater alcohol and cannabis consumption. Endorsing more alcohol-only motives and cannabis-only motives than typical resulted in greater odds of experiencing a negative consequence when accounting for consumption. This within-person effect was not statistically significant for simultaneous-use motives/consequences. Endorsing a greater number of motives across the study (i.e., between person) was not significantly related to consequences beyond consumption.

CONCLUSIONS

Research has documented the robust effects of specific motives on substance use outcomes. Our novel findings extend this work by demonstrating the risks associated with endorsing multiple motives on a given use day. In addition to motive type, we recommend that the number of motives endorsed on a given day be considered as a potential risk factor to be targeted to reduce harms associated with substance use.

Real-world simultaneous alcohol and cannabis use: An ecological study of situational motives and social and physical contexts

OBJECTIVE

Given the adverse outcomes associated with simultaneous alcohol and marijuana (SAM) use, understanding factors that give rise to occasions of simultaneous use is critical. This study examines the relationships between situational motives and contexts and three situational outcomes: simultaneous alcohol and marijuana use (SAM) use versus cannabis-only use, number of cannabis uses, and subjective effects.

METHOD

Past-month SAM users (n = 341; 52% female; 75% White; 10% Latinx/Hispanic; age 18-24) from three U.S. college campuses completed 8 weeks of surveys up to five times a day. Three-level generalized linear mixed-effects models tested the effects of situational motives and social and physical contexts on occasion type (SAM vs. cannabis-only), cannabis use, and subjective effects.

RESULTS

Situational social and enhancement motives were related to greater odds of SAM relative to cannabis-only use; expansion motives were reported more often on cannabis-only occasions. Using with others and at friends' places, being with others consuming cannabis, and being with others who are intoxicated were more likely when combining alcohol with cannabis. Increased number of cannabis uses and subjective effects in a social context were evident only on cannabis-only occasions. Using alone and using at home were greater on cannabis-only occasions and were associated with lower cannabis use and subjective effects.

CONCLUSIONS

The combination of alcohol and cannabis use occurs during social situations and when motivated by positive reinforcement but number of cannabis uses is not increased when consuming cannabis with alcohol in social situations. Characterizing the complex interplay of situational factors that contribute to risky use will inform interventions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Understanding the motives, contexts, and consequences of unplanned versus planned drinking in daily life

OBJECTIVE

Problematic alcohol use among college students remains a public health concern; thus, there is a need to understand distinct drinking events, such as unplanned and planned drinking. The present study examined motives and social and physical contexts as correlates of unplanned and planned drinking to help inform prevention and intervention.

METHOD

College student alcohol and cannabis users (N = 341; 53% women) completed 56 days of data collection (two 28-day bursts) with five repeated daily surveys. Three-level generalized linear mixed-effects models were used to examine associations among motives, physical and social contexts, and unplanned versus planned drinking. We also examined whether unplanned or planned drinking resulted in greater consumption and negative consequences.

RESULTS

Social and enhancement motives were related to planned drinking, whereas offered motives (i.e., offers of alcohol) and coping motives were linked to unplanned drinking. Drinking at home, with roommates, or alone was associated with unplanned drinking. Drinking at a bar/restaurant, a party, at a friend's place, with friends, with strangers/acquaintances, with a significant other, or with intoxicated people was linked to planned drinking. Unplanned drinking was related to fewer drinks consumed and fewer negative consequences endorsed.

CONCLUSIONS

Findings showed that planned drinking-irrespective of consumption-was related to more negative consequences than unplanned drinking. In addition to targeting intentions to drink, the present study provided specific motives and social and physical contexts that are associated with planned drinking that could be incorporated into ecological momentary interventions focused on harm reduction. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Contextual influences on simultaneous alcohol and cannabis use in a predominately white sample of college students

Objective: Simultaneous alcohol and cannabis (i.e., marijuana [SAM]) use is highly prevalent among young adults and college students and associated with a number of negative consequences compared to single substance use. The current study examined socio-contextual factors (e.g., physical, situational, social) associated with SAM use versus cannabis-only versus alcohol-only use. Method: Data were collected from college student SAM users (N = 313, 53% women, M age = 19.79; 74% White; 10% Hispanic/Latinx) who completed two bursts (28 days) of online repeated daily surveys (RDS). RDS were collected five times per day during both bursts (3 months apart). Results: Results suggested that odds of being at home were greater for cannabis-only use compared to SAM and SAM compared to alcohol-only use. Odds of being at a friend's place were greater for SAM compared to alcohol-only and cannabis-only use. Odds of being at a party were greater for SAM compared to alcohol-only use and odds of being at a bar or restaurant were greater for alcohol-only compared to SAM use. Results also suggested that odds of having more people in a location consistently were greater for SAM compared to cannabis-only use, and alcohol-only compared to cannabis-only use. Conclusion: Physical and social contexts (parties, friend's homes, and being around more people) are significantly associated with SAM use occasions. These findings are well-aligned with a social-ecological framework and suggest intervention and prevention efforts should take a comprehensive approach to reduce harms associated with SAM use. Future work is needed to examine these associations in diverse samples. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Preliminary impact of the COVID-19 pandemic on smoking and vaping in college students

We examined tobacco use changes in young adult college students in the context of the COVID-19 pandemic, focusing on smoking and vaping. First, we evaluated changes in tobacco use from pre to post campus closure focusing on smoking and electronic nicotine vaping frequency (days) and quantity (cigarettes/cartridges per day). Also, given the potential protective effects of pausing (temporarily or permanently discontinuing) smoking or vaping, we evaluated its predictors. We hypothesized that generalized anxiety and moving home would increase the odds of pausing. We also explored effects of COVID-related news exposure and seeking on tobacco use. We re-contacted young adults two years after they completed a study on alcohol and marijuana co-use. A subset (N = 83; 26.6% of the 312 respondents) were enrolled in college and reported use of cigarettes (n = 35) and/or e-cigarettes (n = 69) in the week prior to their campus closing (PC). Paired sample t-tests compared smoking and vaping frequency and quantity PC to past-week use since closing (SC). Multivariate logistic regression models were fit to examine predictors of pausing. Both smoking and vaping frequency decreased from PC to SC; however, decreased frequency did not correspond to reduced quantity. Twenty-four participants (28.9%) paused past-week use SC. Higher anxiety and moving home (versus living independently) were related to increased odds of pausing, whereas COVID-19 related news exposure and seeking were related to decreased odds of pausing. Characterizing COVID-19 related tobacco use change provides insights into how college students respond to novel health threats and informs potential interventions.

Changes in Alcohol Use and Drinking Context due to the COVID-19 Pandemic: A Multimethod Study of College Student Drinkers

Background

In spring 2020, U.S. universities closed campuses to limit the transmission of COVID‐19, resulting in an abrupt change in residence, reductions in social interaction, and in many cases, movement away from a heavy drinking culture. The present mixed‐methods study explores COVID‐19‐related changes in college student drinking. We characterize concomitant changes in social and location drinking contexts and describe reasons attributed to changes in drinking.

Methods

We conducted two studies of the impact of the COVID‐19 pandemic on drinking behavior, drinking context, and reasons for both increases and decreases in consumption among college students. Study 1 (qualitative) included 18 heavy‐drinking college students (M_age = 20.2; 56% female) who completed semi‐structured interviews. Study 2 (quantitative) included 312 current and former college students who reported use of alcohol and cannabis (M_age = 21.3; 62% female) and who completed an online survey.

Results

In both studies, COVID‐19‐related increases in drinking frequency were accompanied by decreases in quantity, heavy drinking, and drunkenness. Yet, in Study 2, although heavier drinkers reduced their drinking, among non‐heavy drinkers several indices of consumption increased or remained stable . Both studies also provided evidence of reductions in social drinking with friends and roommates and at parties and increased drinking with family. Participants confirmed that their drinking decreased due to reduced social opportunities and/or settings, limited access to alcohol, and reasons related to health and self‐discipline. Increases were attributed to greater opportunity (more time) and boredom and to a lesser extent, lower perceived risk of harm and to cope with distress.

Conclusion

This study documents COVID‐19‐related changes in drinking among college student drinkers that were attributable to changes in context, particularly a shift away from heavy drinking with peers to lighter drinking with family. Given the continued threat of COVID‐19, it is imperative for researchers, administrators, and parents to understand these trends as they may have lasting effects on college student drinking behaviors.

Patterns, Consequences, and Motives in Simultaneous Use of Prescription Stimulant Medication with Alcohol and Marijuana

Nonmedical use of prescription stimulants (NPS) continues to be a concern on college campuses. Previous research demonstrates a strong link between NPS and use of other substances, particularly alcohol and marijuana among college students. Simultaneous use of NPS with other substances has become an increasing concern. Given the high rates of NPS and simultaneous NPS with other substances, research examining substance use patterns and motives among students is warranted. Method: This study evaluated group differences in alcohol and marijuana use patterns, consequences, and motives among college students: a) with no NPS history (No NPS); b) engaged in NPS with no simultaneous use (Non-Sim NPS); and c) engaged in simultaneous NPS with alcohol and/or marijuana (Sim NPS). Participants included 1,108 students from three universities who reported past-year marijuana and alcohol use. Results: Overall, 32.8% reported lifetime NPS with 12.5% indicating NPS in the previous 3 months, of which 51.1% reported simultaneous NPS with alcohol and 40.2% with marijuana. Significant group differences for all drinking and marijuana outcomes were found, with heaviest rates among the Sim NPS group, followed by the Non-Sim NPS group, and the No NPS group. The Sim NPS group reported greater motives for using marijuana to alter the effects of other substances. Conclusions: College students engaged in simultaneous NPS with alcohol and marijuana are a high-risk group that should be the focus of prevention and intervention programs in the campus setting.

Does the Combination Matter? Examining the Influence of Alcohol and Cannabis Product Combinations on Simultaneous Use and Consequences in Daily Life

BACKGROUND

Alcohol and marijuana/cannabis are frequently used simultaneously (i.e., SAM use). SAM use is complex, and the ways in which alcohol and cannabis are simultaneously used may reveal differential effects. The purpose of this study was to examine day-level effects of distinct alcohol and cannabis product combinations on simultaneous use and consequences on that day.

METHODS

College student SAM users (N = 274; 50% women; Mage  = 19.82 years) were recruited to complete 54 days of data collection, including 5 repeated daily surveys each day. We identified 12 distinct product combinations reported during SAM-use days. We tested 4 reference groups, with one reflecting the most common use pattern and 3 potentially risky use patterns. We considered 3 outcomes (negative consequences, number of drinks, and number of cannabis uses) and used generalized linear mixed-effects models disentangling within- from between-person effects in all analyses.

RESULTS

Using multiple products (≥2) of alcohol was consistently linked to higher odds of experiencing a negative consequence. Combining beer with only one cannabis product (leaf or concentrate) was consistently associated with lower odds of a consequence. Combining cannabis with multiple alcohol products was associated with heavier alcohol consumption. Using dual cannabis products also was associated with heavier cannabis consumption, but this pattern was not significantly different than using concentrate only on a given day.

CONCLUSION

This is the first study to examine day-level influences of distinct alcohol and cannabis product combinations on consumption and consequences among young adult SAM users. Findings suggest that mixing alcohol products confers greater risk for negative consequences and heavier consumption, whereas there is little difference in cannabis consumption when using concentrate only vs. 2 cannabis products on a given day, except for concentrate + beer. Our findings support existing protective strategies of not mixing alcohol products and avoiding use of cannabis concentrate for SAM use as well.

Changes in Alcohol Consumption Among College Students Due to COVID-19: Effects of Campus Closure and Residential Change

OBJECTIVE

It is well established that college students increase their drinking when they leave home. This study examined changes in drinking as a result of campus closure due to coronavirus disease 2019 (COVID-19), focusing on the influence of living situation.

METHOD

A sample of 312 college students (mean age = 21.2 years; 62% female; 67% White) responded to an online survey regarding their drinking behavior before and after university closures because of COVID-19. Those participants who lived with peers pre-closure and moved home to live with parents post-closure were compared with those who remained living with peers or remained living with parents in terms of changes in frequency and quantity of drinking.

RESULTS

A comparison of pre- to post-closure drinking indicated significant decreases in the typical number of drinks per week (from 11.5 to 9.9) and maximum drinks per day (from 4.9 to 3.3) and a slight increase in typical drinking days per week (from 3 to 3.2). Patterns of change significantly varied across groups. Those who moved from peers to parents showed significantly greater reductions in drinking days (from 3.1 to 2.7), number of drinks per week (from 13.9 to 8.5), and maximum drinks in one day (from 5.4 to 2.9) than those who remained living with peers or with parents. In contrast, the latter two groups significantly increased their frequency (from 3.0 to 3.7 days and 2.0 to 3.3 days, respectively).

CONCLUSIONS

Participants reduced their quantity of drinking during the COVID-19 pandemic. Returning to live with parents during emerging adulthood may be protective for heavy drinking.

Heaviness of Alcohol Use, Alcohol Problems, and Subjective Intoxication Predict Discrepant Drinking Reports in Daily Life

BACKGROUND

Self-reported consumption is pervasive in alcohol research, though retrospective recall bias is a concern. Fine-grained methods are designed to limit retrospection; yet, discrepancies can arise when comparing responses on fine-grained surveys with responses to retrospective surveys across weeks or months. Many fine-grained studies use both repeated daily surveys (RDS) and end-of-day (EOD) summaries, but little research has examined whether these survey types are consistent. The purpose of this study was to quantify the magnitude and directionality of discrepancy between EOD summaries and RDS and identify alcohol-related predictors of discrepancy.

METHODS

As a part of a larger study, college student alcohol and cannabis users (N = 341; 53% women; Mage  = 19.79 years) were recruited to complete 56 days of data collection, including 5 daily assessments of their substance use and related constructs, one of which included an EOD summary of the previous day. Generalized linear mixed-effects models were used to examine between- and within-person predictors of a 5-category, discrepancy outcome: no discrepancy, low discrepancy where RDS < EOD, low discrepancy where EOD < RDS, high discrepancy where RDS < EOD, and high discrepancy where EOD < RDS.

RESULTS

Discrepancies between EOD and RDS were observed in both directions. Alcohol problems predicted more alcohol consumption reported on the EOD survey than across RDS. Within-person alcohol quantity and hourly rate of consumption were most strongly related to less alcohol consumption reported on the EOD survey. Between- and within-person peak subjective intoxication and within-person liquor consumption were associated with discrepancies in both directions.

CONCLUSIONS

Surveys requiring more retrospection may overestimate alcohol consumption in problematic drinkers and underestimate consumption on days where more alcohol is consumed than typical. Evidence also suggests that greater day-to-day instability in alcohol behavior is linked to less consistent reporting overall. More research is needed to discern factors contributing to inconsistent reporting on fine-grained surveys to maximize the validity of reports.

Factor Structure of the Cannabis Use Disorders Identification Test Revised (CUDIT-R) for Men and Women

The Cannabis Use Disorders Identification Test Revised (CUDIT-R) is an 8-item screening instrument designed to identify recent problematic cannabis use over the past 6 months. The purpose of the present study was to investigate the factor structure of the CUDIT-R separately for male and female college students. Participants included 1,390 male and female college students recruited from three state universities (61% female; Age: M= 19.8, SD= 1.3). We conducted exploratory and confirmatory factor analyses followed by tests of measurement invariance including configural invariance, metric invariance and scalar invariance across men and women. Results confirmed a one-factor structure for the CUDIT-R. The number of factors and item loadings were invariant between men and women. However, intercepts were non-invariant for an item asking about consumption of cannabis use indicating that the endorsement of this item varied between men and women. Follow-up validation tests indicated that using a sum score for analyses is appropriate despite non-invariance. However, more research is needed to determine if the cut-off scores of the CUDIT-R should be reevaluated by gender.

Alcohol and marijuana co-use: Consequences, subjective intoxication, and the operationalization of simultaneous use

BACKGROUND

Alcohol and marijuana are frequently co-used with overlapping effects. However, the absence of consistent operational definitions delineating simultaneous alcohol and marijuana use (SAM) from concurrent use (CAM) challenges consistent inferences about these behaviors. This study first examined whether daily alcohol and marijuana co-use predicted substance-use related consequences and subjective intoxication; and then evaluated whether competing operationalizations of SAM and CAM were associated with differences in these outcomes on co-use days.

METHODS

A sample of 341 young adult college students who reported past-month use of both alcohol and marijuana "at the same time so that their effects overlapped" completed a two-wave survey with paired 28-day daily experience sampling bursts examining alcohol and marijuana co-use. Outcomes were (a) daily substance-use related consequences; and (b) daily subjective intoxication. Focal predictors were daily drinks and marijuana uses; daily co-use versus single-substance use (Aim 1) or CAM versus SAM (Aim 2); and their interaction.

RESULTS

Participants reported more negative consequences on co-use days versus marijuana-only days and greater subjective intoxication relative to alcohol or marijuana-only days. Competing operationalizations of SAM, defined as daily co-use occurring within 1-240 min in increments of 1 min, found no difference in consequences or subjective intoxication regardless of operationalization.

CONCLUSION

Co-use days involve greater risk than alcohol-only or marijuana-only days. Although there was no evidence of additional daily risk from simultaneous use regardless of the timeframe used to operationalize it, investigating these effects remains challenging due to the generally small timeframe between substances on co-use days in this sample.

Complex cannabis use patterns: Associations with cannabis consequences and cannabis use disorder symptomatology

BACKGROUND

Historically, cannabis researchers have assumed a single mode and product of cannabis (e.g., smoking plant). However, patterns of use, products (e.g., concentrates, edibles), and modes (e.g. blunts, vaporizers) are diversifying. This study sought to: 1) classify cannabis users into groups based on their use of the full range of cannabis products, and 2) examine user group differences on demographics, cannabis consequences and cannabis use disorder (CUD) symptomatology.

METHODS

In a sample of college students (data collected in Fall 2017), who used cannabis in the past year (N = 1390), latent class analysis (LCA) was used to characterize cannabis users. We then added demographic characteristics, cannabis consequences, and CUD symptomatology scores separately to LCA models to examine class differences.

RESULTS

Five unique classes emerged: high-frequency all-product users, high-frequency plant/moderate-frequency edible and concentrate users, low-frequency plant users, moderate-frequency plant and edible users, and low-frequency edible users. Demographic characteristics, cannabis consequences, and CUD symptomatology differed across classes characterized by frequency as well as product.

CONCLUSIONS

Results reflect the increasing variety of cannabis products, modes, and use patterns among college students. In this sample, frequency of use remains a strong predictor of cannabis-related consequences, in addition to type of product. As variation in cannabis use patterns continue to evolve, it is essential for researchers to conduct comprehensive assessments.

The Interplay Between Marijuana-Specific Risk Factors and Marijuana Use Over the Course of Adolescence

Permissive attitudes and norms about marijuana use and perceptions of low harm from use are considered risk factors for adolescent marijuana use. However, the relationship between risk and use may be reciprocal and vary across development and socializing domains. We examined the bidirectional relationships between marijuana-specific risk factors in individual, parent, peer, and community domains and adolescent marijuana use. Longitudinal data came from a sample of 2002 adolescents in 12 communities. Controlling for sociodemographic covariates and communities in which the individuals resided, autoregressive cross-lagged models examined predictive associations between the risk factors and marijuana use. After accounting for concurrent relationships between risk and use and stability in behavior over time, early adolescence and the transition to high school were particularly salient developmental time points. Specifically, higher risk in all four domains in grades 7 and 9 predicted greater use 1 year later. Moreover, youth's perception of lax community enforcement of laws regarding adolescent use at all time points predicted increases in marijuana use at the subsequent assessment, and perceived low harm from use was a risk factor that prospectively predicted more marijuana use at most of the time points. Finally, greater frequency of marijuana use predicted higher levels of risk factors at the next time point in most socializing domains throughout adolescence. Prevention programs should take into account developmental transitions, especially in early adolescence and during the transition to high school. They also should focus on the reciprocal relationships between use and risk across multiple socializing domains.

Simultaneous Alcohol and Marijuana Use: A Brief Measure of Motives

OBJECTIVE

Increasing numbers of substance users report simultaneous alcohol and marijuana (SAM) use such that their effects overlap. More research is needed to understand what motivates this behavior, especially to inform interventions that address SAM use. A 26-item measure of SAM motives was designed and tested in previous research. The purpose of the current study was to validate that measure and create a briefer version of it.

METHOD

Using two waves of data from a multi-site sample of college students (n = 1,014), exploratory and confirmatory factor analyses were conducted to develop a brief 11-item SAM Motives Measure (B-SMM). Negative binomial regression analyses were conducted to assess the reliability and validity of both the original and brief measures.

RESULTS

The brief measure contains four subscales (conformity, positive effects, calm/coping, and social) that match the empirically supported motivational model of substance use. Internal consistency of the subscales ranged from .77 to .87. Most subscales significantly predicted frequency and consequences of SAM use both concurrently and prospectively.

CONCLUSIONS

The psychometrically sound measure developed in this study facilitates the examination of SAM motives in clinical settings with time-constrained patient contact and can be valuable for research involving frequent and repeated measures of substance use behaviors.

Consequences of alcohol and marijuana use among college students: Prevalence rates and attributions to substance-specific versus simultaneous use

College students who use alcohol and marijuana often use them simultaneously, so that their effects overlap. The present study examined whether negative consequences experienced by simultaneous alcohol and marijuana (SAM) users vary from those experienced by individuals who use alcohol and marijuana concurrently but not simultaneously (CAM) or single-substance users. We considered 9 types of consequences: cognitive, blackout, vomiting, academic/occupational, social, self-care, physical dependence, risky behaviors, and driving under the influence (DUI). Further, we examined whether consequences experienced by SAM users are attributed to using alcohol, marijuana, or both simultaneously. The sample included past-year alcohol and marijuana users age 18-24 (N = 1,390; 62% female; 69% White; 12% Hispanic) recruited from 3 U.S. college campuses. SAM users experienced a greater overall number of consequences than CAM or alcohol-only users, even controlling for frequency and intensity of alcohol and marijuana use and potentially confounding psychosocial and sociodemographic factors. Experiencing specific consequences differed between simultaneous and concurrent users, but after adjusting for consumption and other covariates, only blackouts differed. In contrast, SAM users were more likely to experience each consequence than alcohol-only users, with strongest effects for DUI, blackouts, and cognitive consequences. Among SAM users, consequences were most likely to be attributed to alcohol and were rarely attributed to simultaneous use. Being a user of both alcohol and marijuana and using alcohol and marijuana together so that their effects overlap each contribute to risk, suggesting there is value in targeting the mechanisms underlying type of user as well as those underlying type of use. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Simultaneous Alcohol and Marijuana Use: A Brief Measure of Motives

OBJECTIVE

Increasing numbers of substance users report simultaneous alcohol and marijuana (SAM) use such that their effects overlap. More research is needed to understand what motivates this behavior, especially to inform interventions that address SAM use. A 26-item measure of SAM motives was designed and tested in previous research. The purpose of the current study was to validate that measure and create a briefer version of it.

METHOD

Using two waves of data from a multi-site sample of college students (n = 1,014), exploratory and confirmatory factor analyses were conducted to develop a brief 11-item SAM Motives Measure (B-SMM). Negative binomial regression analyses were conducted to assess the reliability and validity of both the original and brief measures.

RESULTS

The brief measure contains four subscales (conformity, positive effects, calm/coping, and social) that match the empirically supported motivational model of substance use. Internal consistency of the subscales ranged from .77 to .87. Most subscales significantly predicted frequency and consequences of SAM use both concurrently and prospectively.

CONCLUSIONS

The psychometrically sound measure developed in this study facilitates the examination of SAM motives in clinical settings with time-constrained patient contact and can be valuable for research involving frequent and repeated measures of substance use behaviors.

Prevalence and Correlates of Concurrent and Simultaneous Cannabis and Cigarette Use among Past-Year Cannabis-Using US College Students

Background: Cannabis and tobacco use are significant public health concerns among young adults, with concurrent (in the same time period) and simultaneous (at the same time so the effects overlap) use of both substances on the rise. Few studies have examined these behaviors among college students. Objective: We examined the prevalence of concurrent and simultaneous cannabis and cigarette (combustible or electronic) use among a sample of college students and characterized the psychosocial predictors of concurrent and simultaneous use compared to using cannabis alone. Methods: Data on past-3 months cannabis and cigarette use were collected on 1352 college students who were past-year cannabis and alcohol users yielding four groups: cannabis-only users (n = 686), concurrent cannabis and cigarette users (CCAC; n = 235), simultaneous cannabis and cigarette users (SCAC; n = 293), and non-recent users of either substance (n = 138). Multinomial logistic regression analyses were utilized to predict group membership. Results: Relative to the cannabis-only group, White, compared to Non-White students, males, compared to females, frequent, compared to infrequent, alcohol users, including those who used alcohol simultaneously with cigarettes, and illicit drug users were more likely to belong to the CCAC or SCAC group. Conclusions: Findings suggest the need for unique intervention efforts to prevent onset or reduce co-use among male and White students as well as illicit drug users and frequent alcohol users.

Simultaneous Alcohol and Marijuana Use Among College Students: Patterns, Correlates, Norms, and Consequences

BACKGROUND

Alcohol and marijuana users often engage in simultaneous alcohol and marijuana (SAM) use (i.e., using the 2 substances together so that their effects overlap), which can result in more negative consequences than using either substance alone. Nevertheless, little is known about SAM use among contemporary college students to aid in the development of preventive interventions. This study examined SAM use patterns, demographic correlates of SAM use, and normative influences on SAM use and related negative consequences among college students.

METHODS

Students who had used alcohol and marijuana in the past year were recruited from 3 state universities in states with different laws regarding recreational marijuana use (N = 1,389). They completed an online survey, which assessed their own alcohol, marijuana, and SAM use and related consequences, their perceptions of the proportion of same-gender peers and close friends who engaged in SAM use, marijuana access, and demographic characteristics.

RESULTS

About three-fourths of participants reported at least 1 occasion of SAM use in the past year with an average frequency of twice per month among SAM users. There were significant differences in SAM use prevalence and frequency by sociodemographic characteristics controlling for past-year alcohol and marijuana frequency. Students in a state with decriminalized recreational marijuana use reported higher frequency of past-year SAM use than students in states with legalized or criminalized use. There were significant demographic differences in perceived norms regarding SAM use among close friends and same-gender peers. SAM users endorsed significantly higher perceived peer and friend norms than nonusers. Also, higher perceived norms predicted more frequent SAM use and more negative consequences of use.

CONCLUSIONS

Results indicate a need for prevention programs on college campuses that address SAM use. Interventions that use personalized normative feedback may be effective.

Multivariate Higher-Order IRT Model and MCMC Algorithm for Linking Individual Participant Data From Multiple Studies

Many clinical and psychological constructs are conceptualized to have multivariate higher-order constructs that give rise to multidimensional lower-order traits. Although recent measurement models and computing algorithms can accommodate item response data with a higher-order structure, there are few measurement models and computing techniques that can be employed in the context of complex research synthesis, such as meta-analysis of individual participant data or integrative data analysis. The current study was aimed at modeling complex item responses that can arise when underlying domain-specific, lower-order traits are hierarchically related to multiple higher-order traits for individual participant data from multiple studies. We formulated a multi-group, multivariate higher-order item response theory (HO-IRT) model from a Bayesian perspective and developed a new Markov chain Monte Carlo (MCMC) algorithm to simultaneously estimate the (a) structural parameters of the first- and second-order latent traits across multiple groups and (b) item parameters of the model. Results from a simulation study support the feasibility of the MCMC algorithm. From the analysis of real data, we found that a bivariate HO-IRT model with different correlation/covariance structures for different studies fit the data best, compared to a univariate HO-IRT model or other alternate models with unreasonable assumptions (i.e., the same means and covariances across studies). Although more work is needed to further develop the method and to disseminate it, the multi-group multivariate HO-IRT model holds promise to derive a common metric for individual participant data from multiple studies in research synthesis studies for robust inference and for new discoveries.

Does Substance Use Exacerbate Escalation along Developmental Pathways of Covert and Overt Externalizing Behaviors among Young Men?

OBJECTIVES

The delinquency Pathways Model proposes that the majority of those who engage in serious delinquent acts have gone through a sequence of externalizing behaviors from less to more serious delinquent behaviors. This study examined whether frequency of alcohol, marijuana, and hard drugs exacerbated escalation through the covert and overt pathways.

METHODS

Data came from the youngest cohort of the Pittsburgh Youth Study (N = 503). The young men were followed from mean age 7 through mean age 20. Sequences of offending were based on ages of onset of covert and overt delinquent behaviors. Survival analyses were conducted to examine the associations of frequency of use with risk for and timing of movement from the lowest to highest level in each pathway.

RESULTS

Frequency of alcohol and marijuana use was related to greater risk of moving from the lowest to highest level in both pathways and hard drug use vs. nonuse was associated with moving from minor aggression to violence.

CONCLUSIONS

Reducing frequency of substance use may interrupt escalation through the covert and overt pathways for young men once they enter the first level.

The association between regular marijuana use and adult mental health outcomes

OBJECTIVE

The present study is a prospective examination of the relationship between regular marijuana use from adolescence through young adulthood and mental health outcomes at age 33.

METHODS

Data came from a gender-balanced, ethnically diverse longitudinal panel of 808 participants from Seattle, Washington. Outcomes included symptom counts for six mental health disorders. Regular marijuana use was tracked during adolescence and young adulthood. Regression analyses controlled for demographics and early environment, behaviors, and individual risk factors.

RESULTS

Nonusers of marijuana reported fewer symptoms of alcohol use disorder, nicotine dependence, and generalized anxiety disorder than any category of marijuana users. More persistent regular marijuana use in young adulthood was positively related to more symptoms of cannabis use disorder, alcohol use disorder, and nicotine dependence at age 33.

CONCLUSIONS

Findings highlight the importance of avoiding regular marijuana use, especially chronic use in young adulthood. Comprehensive prevention and intervention efforts focusing on marijuana and other substance use might be particularly important in the context of recent legalization of recreational marijuana use in Washington and other U.S. states.

Early predictors of maturing out of marijuana use among young men

OBJECTIVE

Although several studies have delineated risk factors for adolescent regular marijuana use, few studies have identified those factors that differentiate who will and will not eventually stop using marijuana during young adulthood. This study examined the extent to which adolescent risk factors, including individual attitudes, temperament, and behaviors and peer, family, and neighborhood factors, could prospectively identify which adolescence-onset monthly marijuana users (AMMU) would stop using marijuana in young adulthood and whether race moderated these associations.

METHOD

Data came from 503 young men who were followed annually from the first grade through mean age 20 and then re-interviewed at mean ages 26 and 29. Young men who used marijuana at least monthly at least one year between ages 14 and 17 (N=140) were compared to their peers who had not tried marijuana by age 17 (N=244). The former group was divided into those who used at least weekly in adulthood (N=54) and those who did not use at all in adulthood (N=66) and these groups were compared to each other.

RESULTS

Logistic regression analyses indicated that all except one of the adolescent risk factors significantly differentiated AMMU from nonusers. None of the predictors differentiated those who matured out from those who used weekly in young adulthood.

CONCLUSIONS

Future research on marijuana cessation should incorporate subjective life experiences, such as reasons for using and negative consequences from use, to help identify adolescents who are at risk for problematic use in adulthood.

Do drinking motives distinguish extreme drinking college students from their peers?

OBJECTIVE

The literature highlights the need to move beyond the traditional heavy episodic ("binge") drinking criteria when trying to identify at-risk college drinkers. Thus, recent attention has focused on more extreme levels of drinking. This study examines whether drinking motives can distinguish college student extreme drinkers from lighter drinkers.

METHOD

We used data from 3518 college student current drinkers (63.4% women) who participated in eight different studies at five different college campuses across the United States; a subsample of these students was followed up at 6months post-baseline. At baseline and follow-up, drinkers were divided into three groups: nonbinge drinkers (<4 drinks for women and 5 for men on their maximum drinking occasion), binge drinkers (4-7 drinks for women; 5-9 for men), and extreme drinkers (8+ for women and 10+ for men).

RESULTS

At baseline, extreme drinkers, compared to nonbinge and binge drinkers, reported greater social, enhancement, and coping motives, as well as greater quantity and frequency of drinking per week and more alcohol-related problems. Those who were not extreme drinkers at baseline and later became extreme drinkers at follow-up reported significantly greater increases in social and enhancement motives, compared to those who remained nonextreme drinkers. Those who were extreme drinkers at baseline and reduced their drinking 6months later, compared to those who remained extreme drinkers, reported greater reductions in enhancement and coping motives.

CONCLUSIONS

Focusing on drinking motives might be an efficacious target for preventive intervention programs to reduce extreme drinking among college students.

Changes in Substance use during the Transition to Adulthood: A Comparison of College Students and Their Noncollege Age Peers

This study examines transitions in alcohol, cigarette, and marijuana use and alcohol- and marijuana-related problems from late adolescence through young adulthood. Men and women who attend college are compared to their peers who do not to determine if the situational/socialization effects of college are unique during this developmental period. Prospective data from a community sample were collected at ages 18, 21, and 30 years. ANOVAs revealed that 18 year olds who transition out of high school, regardless of college status, reported higher levels of substance use than their peers who were still in high school. In addition, nonstudents compared to college students reported higher levels of cigarette and marijuana use in adolescence, emerging adulthood, and young adulthood and higher levels of alcohol- and marijuana-related problems in adolescence and young adulthood. Latent growth curve analyses revealed that college status was related to lower levels of alcohol and marijuana problems at age 18, greater increases from ages 18 to 21, and greater decreases from ages 21 to 30 even after controlling for level and growth in use. Overall, the findings suggest that nonstudents may be a more important target group than college students for drug use prevention efforts during emerging adulthood.

Trends in Alcohol use, Cocaine use, and Crime: 1989–1998

The widespread belief that illicit drugs are closely associated with crime has contributed to America's “War on Drugs” and attendant increases in arrests, convictions, and prison populations. However, the links between alcohol and crime have received less attention from policy makers and the public despite consistent evidence that alcohol is more likely than other drugs to be associated with violence. This study explores the relationship between alcohol and cocaine use and crime from 1989–1998, based on findings from the Drug Use Forecasting/Arrestee Drug and Alcohol Monitoring Program and the Uniform Crime Reports Program. We examine correlations among cocaine use, alcohol use, property crime, and violent crime at the city level to determine if there is a consistent pattern across cities over time. The analyses show a wide variation across cities in the links between both alcohol and cocaine use and violent and property crime rates over the 10-year period. However, the association between the annual rates of alcohol use and violent crime is stronger than that of alcohol use and property crime. These associations for alcohol remain in multivariate analyses, including statistical controls for temporal autocorrelation, SES, and heroin use. Cocaine use, in contrast, is not closely associated with either property or violent crime rates in the multivariate analyses. The findings suggest that to reduce violent crime rates, policy makers need to focus on addressing the contribution of alcohol. Furthermore, given the variation found across sites, efforts to reduce the drug/alcohol-crime links need to be tailored to local patterns and problems.

Unfazed or Dazed and Confused: Does Early Adolescent Marijuana Use Cause Sustained Impairments in Attention and Academic Functioning?

There is some suggestion that heavy marijuana use during early adolescence (prior to age 17) may cause significant impairments in attention and academic functioning that remain despite sustained periods of abstinence. However, no longitudinal studies have examined whether both male and female adolescents who engage in low (less than once a month) to moderate (at least once a monthly) marijuana use experience increased problems with attention and academic performance, and whether these problems remain following sustained abstinence. The current study used within-individual change models to control for all potential pre-existing and time-stable confounds when examining this potential causal association in two gender-specific longitudinal samples assessed annually from ages 11 to 16 (Pittsburgh Youth Study N = 479; Pittsburgh Girls Study N = 2296). Analyses also controlled for the potential influence of several pertinent time-varying factors (e.g., other substance use, peer delinquency). Prior to controlling for time-varying confounds, analyses indicated that adolescents tended to experience an increase in parent-reported attention and academic problems, relative to their pre-onset levels, during years when they used marijuana. After controlling for several time-varying confounds, only the association between marijuana use and attention problems in the sample of girls remained statistically significant. There was no evidence indicating that adolescents who used marijuana experienced lingering attention and academic problems, relative to their pre-onset levels, after abstaining from use for at least a year. These results suggest that adolescents who engage in low to moderate marijuana use experience an increase in observable attention and academic problems, but these problems appear to be minimal and are eliminated following sustained abstinence.

Brief motivational interventions for college student drinking may not be as powerful as we think: an individual participant-level data meta-analysis

BACKGROUND

For over 2 decades, brief motivational interventions (BMIs) have been implemented on college campuses to reduce heavy drinking and related negative consequences. Such interventions include in-person motivational interviews (MIs), often incorporating personalized feedback (PF), and stand-alone PF interventions delivered via mail, computer, or the Web. Both narrative and meta-analytic reviews using aggregate data from published studies suggest at least short-term efficacy of BMIs, although overall effect sizes have been small.

METHODS

This study was an individual participant-level data (IPD) meta-analysis of 17 randomized clinical trials evaluating BMIs. Unlike typical meta-analysis based on summary data, IPD meta-analysis allows for an analysis that correctly accommodates the sampling, sample characteristics, and distributions of the pooled data. In particular, highly skewed distributions with many zeroes are typical for drinking outcomes, but have not been adequately accounted for in existing studies. Data are from Project INTEGRATE, one of the largest IPD meta-analysis projects to date in alcohol intervention research, representing 6,713 individuals each with 2 to 5 repeated measures up to 12 months postbaseline.

RESULTS

We used Bayesian multilevel over dispersed Poisson hurdle models to estimate intervention effects on drinks per week and peak drinking, and Gaussian models for alcohol problems. Estimates of overall intervention effects were very small and not statistically significant for any of the outcomes. We further conducted post hoc comparisons of 3 intervention types (individual MI with PF, PF only, and group MI) versus control. There was a small, statistically significant reduction in alcohol problems among participants who received an individual MI with PF. Short-term and long-term results were similar.

CONCLUSIONS

This study questions the efficacy and magnitude of effects of BMIs for college drinking prevention and intervention and suggests a need for the development of more effective intervention strategies.

Are there secondary effects on marijuana use from brief alcohol interventions for college students?

OBJECTIVE

This study examined whether brief motivational interventions (BMIs) designed for reducing heavy drinking among college students have secondary effects on reducing marijuana use.

METHOD

The data came from Project INTEGRATE, which combined data from 24 independent trials of BMIs and other individual-focused interventions designed to reduce heavy drinking and related problems among college students. We analyzed data from 10 samples across nine studies that used random assignment of participants into either a BMI or a control group and assessed marijuana use outcomes (N = 6,768; 41.5% men; 73.2% White; 57.7% first-year students; 19.2% current marijuana users at baseline). We derived three marijuana use groups within studies by cross-tabulating baseline and follow-up data: Nonusers, Reducers, and Stayers/Increasers.

RESULTS

Peto's one-step odds ratio analyses for meta-analysis revealed no significant intervention effects on marijuana use at either short-term (1-3 month) or long-term (6-12 month) follow-up. Subsequent exploratory analyses showed that those who reduced drinking were more likely to be a marijuana Reducer or Nonuser, compared with a Stayer/Increaser, at both follow-ups.

CONCLUSIONS

The BMIs to reduce heavy drinking evaluated in this study did not reduce marijuana use. However, our exploratory results suggest that if we can develop interventions for college students that effectively reduce drinking, we may also reduce their marijuana use. Furthermore, as recreational use of marijuana becomes legal or decriminalized and marijuana becomes more readily available, it may be necessary to develop interventions specifically targeting marijuana use among college students.

GROWING UP IS HARD TO DO: AN EMPIRICAL EVALUATION OF MATURATION AND DESISTANCE

PURPOSE

With an increase in longitudinal datasets and analyses, scholars have made theoretical advances toward understanding desistance, using biological, social, and psychological factors. In an effort to integrate the theoretical views on desistance, some scholars have argued that each of these views represents a piece of adult maturation. Yet to date, research has not empirically examined an integrated perspective. The purpose of this study is to conduct an exploratory examination of various "domains" of maturation to determine whether they explain desistance from crime separately and as a whole.

METHODS

Using the Rutgers Health and Human Development Project, a longitudinal study spanning ages 12-31, we develop exploratory measures of maturation in five domains: 1) adult social roles, 2) identity/cognitive, 3) psychosocial, 4) civic, and 5) neurocognitive. We then utilize growth curve models to examine the relationship between these domains and crime over time.

RESULTS

Although each of the domains is associated with crime at the bivariate level, only three (i.e., psychosocial, identity/cognitive transformation, and adult social role) remain significant in the growth curve models (2 in within-individual analyses). In addition, a combined measure of maturation is related to crime, indicating that greater maturation through emerging adulthood has a negative effect on criminal behavior and is, therefore, a factor influencing desistance.

CONCLUSIONS

Maturation emerges as a promising approach to integrating the multiple theoretical views that characterize the literature on desistance from crime. Further research should develop additional domains and determine the best approach for measurement.

Divergent marijuana trajectories among men: Socioeconomic, relationship, and life satisfaction outcomes in the mid-30s

BACKGROUND

Given recent changes in marijuana policy in the United States, it is important to understand the long-term effects of marijuana use on adult functioning. We examined whether men who displayed different trajectories of marijuana use from adolescence through emerging adulthood (age ∼15-26) differed in terms of socioeconomic, social, and life satisfaction outcomes in their mid-30s.

METHODS

Data came from a longitudinal sample of men who were recruited in early adolescence (N=506) and followed into adulthood. Four trajectory groups based on patterns of marijuana use from adolescence into emerging adulthood were compared on adult outcomes (age ∼36) before and after controlling for co-occurring use of other substances and several pre-existing confounding factors in early adolescence. The potential moderating effect of race was also examined.

RESULTS

Although there were initially group differences across all domains, once pre-existing confounds and co-occurring other substance use were included in the model, groups only differed in terms of partner and friend marijuana use. Chronic marijuana users reported the highest proportions of both. Frequent and persistent marijuana use was associated with lower socioeconomic status (SES) for Black men only.

CONCLUSIONS

After statistically accounting for confounding variables, chronic marijuana users were not at a heightened risk for maladjustment in adulthood except for lower SES among Black men. Chronic users were more likely to have friends and partners who also used marijuana. Future studies should take into account pre-existing differences when examining outcomes of marijuana use.

A Hierarchical Multi-Unidimensional IRT Approach for Analyzing Sparse, Multi-Group Data for Integrative Data Analysis

The present paper proposes a hierarchical, multi-unidimensional two-parameter logistic item response theory (2PL-MUIRT) model extended for a large number of groups. The proposed model was motivated by a large-scale integrative data analysis (IDA) study which combined data (N = 24,336) from 24 independent alcohol intervention studies. IDA projects face unique challenges that are different from those encountered in individual studies, such as the need to establish a common scoring metric across studies and to handle missingness in the pooled data. To address these challenges, we developed a Markov chain Monte Carlo (MCMC) algorithm for a hierarchical 2PL-MUIRT model for multiple groups in which not only were the item parameters and latent traits estimated, but the means and covariance structures for multiple dimensions were also estimated across different groups. Compared to a few existing MCMC algorithms for multidimensional IRT models that constrain the item parameters to facilitate estimation of the covariance matrix, we adapted an MCMC algorithm so that we could directly estimate the correlation matrix for the anchor group without any constraints on the item parameters. The feasibility of the MCMC algorithm and the validity of the basic calibration procedure were examined using a simulation study. Results showed that model parameters could be adequately recovered, and estimated latent trait scores closely approximated true latent trait scores. The algorithm was then applied to analyze real data (69 items across 20 studies for 22,608 participants). The posterior predictive model check showed that the model fit all items well, and the correlations between the MCMC scores and original scores were overall quite high. An additional simulation study demonstrated robustness of the MCMC procedures in the context of the high proportion of missingness in data. The Bayesian hierarchical IRT model using the MCMC algorithms developed in the current study has the potential to be widely implemented for IDA studies or multi-site studies, and can be further refined to meet more complicated needs in applied research.