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

Longitudinal patterns of alcohol and cannabis use among US young adults: Correlates and implications for problematic health outcomes

INTRODUCTION

Alcohol and cannabis use are common during young adulthood. Less is known regarding correlates of alcohol-cannabis use patterns and related problematic health outcomes.

METHODS

Using longitudinal survey data (Fall 2018, 2019, 2020) from 2,194 young adults (YAs; ages 18-34), bivariate analyses and multivariable logistic regressions examined: (1) Wave 1 (W1) sociodemographics and psychosocial factors (i.e., adverse childhood experiences [ACEs], depressive symptoms, personality traits, parent and peer alcohol and cannabis use) in relation to W3 past-month use group (i.e., use of neither, alcohol only, cannabis only, both/co-use); and (2) W3 use group in relation to W5 problematic alcohol use (Alcohol Use Disorder Identification Test), problematic cannabis use (Cannabis Use Disorder Identification Test), and depressive/anxiety symptoms (Patient Health Questionnaire - 4 item).

RESULTS

Overall, 42.3% reported W3 alcohol-only use, 34.9% co-use, 17.8% no use, and 5.0% cannabis-only use. Those reporting W3 co-use reported greater W1 extraversion, openness, friend alcohol/cannabis use, and were more likely to report parent cannabis use (vs. no use); reported less conscientiousness, greater friend cannabis use, and were more likely to report depressive symptoms and parent cannabis use (vs. alcohol-only use); and reported greater friend alcohol use, and were more likely to report parent alcohol use (vs. cannabis-only use). W3 co-use was associated with higher odds of W5 problematic alcohol use (vs. alcohol-only use) and problematic cannabis use (vs. cannabis-only use).

CONCLUSIONS

Substance use messaging and interventions should consider YAs' alcohol-cannabis co-use and the unique correlates of such use.

Examining within-person associations between alcohol and cannabis use and hooking up among adolescents and young adults in the United States

OBJECTIVE

This study examined daily associations between alcohol use, cannabis use, and simultaneous alcohol and cannabis/marijuana (SAM) use with the likelihood of hooking up (uncommitted sexual encounter that may or may not include intercourse).

METHOD

We used a longitudinal measurement burst ecological momentary assessment (EMA) design with 3-week EMA bursts with daily measurements repeated quarterly across 12 months. 1,009 (57 % female, Mean age = 20.00 [SD = 3.21]) Texan adolescents and young adults ages 15-25 participated in the study. Mixed effects logistic regression models were estimated using maximum likelihood estimation to evaluate the associations between substance use and hooking up.

RESULTS

Within-person results indicated that participants were more likely to hook up on days with alcohol use and on days with cannabis use, but not on days with SAM use. Participants were also more likely to hook up on drinking days with higher-than-usual alcohol use. Between-person results indicated that participants who used alcohol more often or cannabis more often on average were more likely to hook up, and participants who tended to drink more on drinking days were more likely to hook up.

CONCLUSIONS

Given the significant daily-level associations between alcohol and cannabis use and hooking up behavior, public health initiatives should focus on developing interventions to reduce alcohol and cannabis use and promote safer hooking up behavior among adolescents and young adults.

Simultaneous Alcohol and Cannabis Use and High-Risk Sexual Behaviors

Background

Alcohol and cannabis use rates are highest in college-aged young adults, and both alcohol and cannabis use are independently related to high-risk sexual behaviors (HRSBs). HRSBs (e.g., sex without protection against sexually transmitted infections) are a prevalent public health problem in college students, with little research examining simultaneous alcohol and cannabis use (i.e., using both alcohol and cannabis at the same time so the effects overlap) and HRSBs.

Method

We examined simultaneous alcohol and cannabis-related HRSB frequency, gender differences in simultaneous alcohol and cannabis-related HRSBs, and differences in HRSBs between simultaneous and non-simultaneous users. Alcohol and cannabis using college students (N = 534; Average Age = 19; 66.9% reported identifying as female) were recruited through a psychology department's human subjects research pool and completed a one-time, online, self-report survey.

Results

One-third of participants engaged in simultaneous alcohol and cannabis use prior to sexual intercourse in the past 3 months. Additionally, over one-third of participants reported heavy drinking (4/5 or more drinks for women/men) simultaneously with cannabis use prior to sexual intercourse in the past 3 months. Simultaneous alcohol and cannabis use was significantly and positively related to sexual intercourse after simultaneous use and after heavy drinking simultaneously with cannabis use. Past year simultaneous alcohol and cannabis users, relative to non-simultaneous users, reported increased incidents of sex without protection against sexually transmitted infections. No gender differences in simultaneous alcohol and cannabis-related HRSBs were found.

Conclusions

Future research should continue examining simultaneous alcohol and cannabis use and HRSBs.

Changes in co-use of alcohol and cannabis among Nordic adolescents in the 21st century: Results from the European School Survey Project on Alcohol and Other Drugs study

INTRODUCTION

In the 21st century, there has been a decline in alcohol use among adolescents in most Nordic countries, while trends of cannabis use have diverged. We explore how alcohol and cannabis use, respectively, and co-use of the two substances, have changed among Nordic adolescents. Three hypotheses are used to frame the study: (i) cannabis use has substituted alcohol use; (ii) there has been a parallel decline in both substances; and/or (iii) there has been a 'hardening' of users, implying that alcohol users increasingly use cannabis.

METHODS

Data from the European School Survey Project on Alcohol and Other Drugs, conducted among 15- to 16-year-olds in Denmark, Finland, Iceland, Norway and Sweden (N = 74,700, 49% boys), were used to explore trends of past-year alcohol and cannabis use in the period 2003-2019.

RESULTS

The proportion of adolescents reporting alcohol use decreased significantly in all Nordic countries except Denmark. The proportion of those using cannabis only was low (0.0%-0.7%) and stable in all countries. The total number of substance use occasions declined among all adolescents in all countries but Denmark. Among alcohol users, cannabis use became increasingly prevalent in all countries but Denmark.

DISCUSSION AND CONCLUSIONS

We found no support for the 'parallel decline hypothesis' in alcohol and cannabis use among Nordic adolescents. Partially in line with the 'substitution hypothesis', cannabis use accounted for an increasing proportion of all substance use occasions. Our results suggests that the co-use of alcohol and cannabis has become more common, thus also providing support to the 'hardening' hypothesis.

The Mediating Effect of Danger Invulnerability in the Relationship Between Sensation Seeking and Gambling Among University Students

The association between sensation-seeking and gambling is well established, yet the research on mediators of this relationship is limited. The proposed model of the present study includes sensation seeking as an antecedent variable, danger invulnerability as a mediator, and gambling frequency as an outcome variable.Self-report data obtained from a convenient sample of 641 university students aged 18-40 years (Mage = 21.25; F = 52.7%, M = 47.3%) were analysed. This study supported proposed hypothesis that both sensation seeking and danger invulnerability are in significant positive relation with the frequency of gambling. Moreover, the results show that tested mediation model fit the data well, and that danger invulnerability completely mediates the relationship between sensation seeking and gambling frequency, such that higher sensation seeking is related to higher danger invulnerability and higher danger invulnerability is related to higher gambling frequency. The model explained 42.4% of the variance in danger invulnerability and 32.7% of the variance in gambling frequency. This study underscores the importance of examining both the direct and indirect effects of different variables on gambling behaviour.

Latent Classes of Simultaneous Alcohol and Cannabis Use and Associations with Consequences using Daily Data

Objective

Simultaneous alcohol and cannabis use (i.e., marijuana, [SAM], using alcohol and cannabis so effects overlap) is associated with increased consumption and consequences compared to single-substance use. SAM use prevalence is increasing, yet there is heterogeneity in use patterns among those engaging in SAM use, which may lead to differential consequences.

Method

This study drew on daily data to characterize latent profiles of cannabis, alcohol, and SAM use patterns and to test class differences on related consequences after 3 months among college students engaging in SAM use (77.08% White, 51.67% female). Class indicators were 10 person-level substance use variables derived from repeated daily surveys.

Results

Results yielded a three-class solution: Heavy Alcohol, Cannabis, and SAM (Heavy Use, n = 105); Heavy Alcohol-Light Cannabis (n = 75); and Light Alcohol-Heavy Cannabis (n = 60). There were significant person-level differences between classes on all substance use indicators (e.g., quantity and frequency of alcohol, cannabis, and SAM) but not sex or race/ethnicity. At 3-month follow-up, the Heavy Use class endorsed more SAM consequences than the other classes. The Heavy Use class did not differ on alcohol or cannabis consequences compared to the Heavy Alcohol-Light Cannabis or Light Alcohol-Heavy Cannabis classes, respectively. The Light Alcohol-Heavy Cannabis class endorsed the fewest alcohol consequences. The Heavy Alcohol-Light Cannabis class endorsed the fewest cannabis consequences.

Conclusions

Findings highlight distinct patterns of co-use and their association with consequences at follow-up. Heavy alcohol or cannabis use was associated with consequences for that substance, but heavy use of only one substance was not indicative of SAM-specific consequences.

Assessment of simultaneous alcohol and cannabis use and its related consequences and cognitions in college students: A narrative review

As rates of students using cannabis continue to rise, simultaneous use of alcohol and cannabis (such that their effects overlap; commonly referred to as simultaneous alcohol and marijuana [SAM] use) is prevalent among college students who use both substances. Although research focusing on SAM use and related cognitions and consequences continues to grow, there are no common established measures, as approaches vary across studies. This narrative review identifies current methods for assessing SAM use and measures of SAM-related consequences and cognitions (motives and expectancies) among college students, evaluates how they were developed, identifies gaps in the literature, and provides recommendations for future directions of assessment. We conclude that the assessment of SAM use is limited by difficulties in the assessment of cannabis quantity and potency. However, and the lack of a psychometrically validated measure of SAM consequences. However, measures of SAM motives and expectancies have been published with support from psychometric examinations such as exploratory factor analysis, confirmatory factor analysis, and measurement invariance. Research is needed that incorporates qualitative approaches in the development of SAM use measures so that unique items specific to SAM use rather than single-substance use can be identified. Additionally, validation of these measures is needed across different samples that vary demographically, such as by race and gender or sex. Future research should consider the development of a measure of protective behavioral strategies  specific to SAM use to inform interventions that target the reduction of negative consequences of SAM use.

Normative Perceptions of Sexual Behavior and Alcohol Use among Bisexual Women

Background: As compared to heterosexual and lesbian women, bisexual women report higher rates of alcohol, other substance use, and risky sexual behavior, and they experience more negative outcomes from these behaviors. Descriptive norms (i.e., perceptions of others' behavior) are an important predictor of risky behaviors, but scant research has examined whether bisexual women's perceptions of other bisexual women's alcohol use and sexual behavior are associated with their own alcohol or drug use during sex. Objectives: Consequently, the present study examined (1) whether perceived sex norms were related to engagement in sex and (2) the relative influence of drinking and sex norms on engaging in sex while drinking among bisexual women. Method: Data were collected from 225 self-identified bisexual women who completed an online survey about their typical weekly alcohol use, engagement in alcohol or drug use during sex in the past 30 days, and normative perceptions of drinking and sexual behavior. Results: Regression models demonstrated both sexual norms and drinking frequency norms were positively associated with alcohol or drug use during sex. In addition, only perceived norms of other bisexual women, compared to perceived norms of lesbian and heterosexual women, predicted engagement in sex. Conclusions: Bisexual women may be susceptible to normative perceptions, given their connectedness to a marginalized social group. Thus, alcohol prevention and intervention efforts aimed at reducing risky consequences among bisexual women should specifically consider drinking and sexual norms of other bisexual women.

Substance Misuse in Elite Athletes: Early Detection, Brief Intervention and Referral to Treatment

Sports medicine physicians and athletic trainers regularly encounter athletes who misuse substances that put them at risk for adverse health, social, interpersonal, academic, psychological, and performance effects. The three most encountered substances are alcohol (binge drinking), cannabis (marijuana), and tobacco/nicotine vaping. Early detection using self-report screening instruments, adverse consequences questionnaires, and urine testing are reviewed. Brief interventions that involve personalized feedback, goal setting, support system involvement, psychoeducation, contingency management, and/or motivational interviewing are highlighted. Lack of response to brief intervention or progression to a substance use disorder should prompt the consideration of referral to a substance specialty level of care.

Sex and Gender Differences in Simultaneous Alcohol and Cannabis Use: a Narrative Review

Purpose of Review

The aim is to review recent literature on sex and gender differences in patterns of use, motives, pharmacological effects, and consequences of simultaneous alcohol and cannabis use (SAC).

Recent Findings

Men engage in SAC more frequently than women. Women may have more substance-specific motives for use, while men tend to consistently endorse social/enhancement motives for both alcohol and cannabis. Regarding pharmacological effects, women experience the same subjective effects as men do at lower levels of use, with some evidence that women modulate cannabis use during simultaneous use episodes to avoid greater subjective intoxication. Finally, women appear more vulnerable to experiencing a range of positive and negative consequences from SAC relative to men.

Summary

Research has identified several important sex/gender differences in SAC and its correlates and consequences. However, research has primarily focused on white and cisgender populations, with a need for more research among racial/ethnic and gender minorities.

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.

Examining Differences in Emotion Dysregulation Between Emerging Adult Alcohol-Only Users, Abstainers, and Simultaneous Users

Objective

Simultaneous use of alcohol and cannabis is associated with more negative consequences than use of either substance alone. Research suggests that emotion dysregulation is linked to alcohol, cannabis, and polysubstance use. However, no previous research has examined whether emotion dysregulation scores differ among individuals without past month substance use (abstainers), individuals who report past-month alcohol use only (no past month cannabis or simultaneous use; alcohol-only users), and individuals who engage in past-month simultaneous alcohol and cannabis use (simultaneous users). Our aim was to examine differences in overall levels of emotion dysregulation and emotion dysregulation subscales between these groups.

Methods

The sample included 468 college students. Participants completed an online survey assessing demographics, emotion dysregulation, average number of drinks per week, days of monthly cannabis use, and simultaneous use of alcohol and cannabis.

Results

A one-way ANOVA showed significant differences in emotion dysregulation between alcohol-only users, abstainers, and simultaneous users. A Bonferroni post hoc analysis revealed significant differences in emotion dysregulation for simultaneous users (p = .004) compared to alcohol-only users and abstainers. A series of ANOVAs were run to examine emotion dysregulation subscale scores and significant differences were found for impulse control difficulties (p = .003) and limited access to emotion regulation strategies (p = .005) for simultaneous users compared to alcohol-only users and abstainers, and for non-acceptance of emotional responses (p = .018) for simultaneous users compared to and alcohol-only users.

Conclusion

These findings indicate that simultaneous users have higher levels of emotion dysregulation, higher levels of impulse control difficulties, greater non-acceptance of emotions, and greater lack of access to emotion regulation strategies compared to abstainers and alcohol-only users.

Alcohol and cannabis use among rural university students: A quantitative analysis of barriers to care, student resilience, and school climate

Objective: This article examines impacts of student resilience, school climate, and barriers to mental health care on problematic drinking behavior and cannabis use among rural university students. Participants: A total of 948 students from a public university in a southeastern state that completed the 2019-2020 Healthy Minds Study. Methods: Cross-tabulations and multivariate logistic regression analyses were employed to test study hypotheses. Results: Students who binge drink are more likely to engage in problematic drinking behaviors than students who do not binge drink; students who engage in problematic drinking are more likely to use cannabis than those who do not engage in problematic drinking. As students face more barriers to mental health care, they are more likely to engage in problematic drinking and cannabis use; students who are more resilient are less likely to engage in problematic drinking. Conclusions: To promote health and wellbeing, universities must understand factors that impact substance use among students.

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.

Evaluating substance use outcomes of recreational cannabis legalization using a unique co-twin control design

Background: As more states pass recreational cannabis legalization (RCL), we must understand how RCL affects substance use.Objectives: The current study aims to examine the effect of RCL on lifetime and past-year use of cannabis, alcohol, tobacco, and other drugs, frequency of cannabis, alcohol, and tobacco use, co-use of cannabis with alcohol and tobacco, and consequences from cannabis and alcohol use.Methods: We used a unique, co-twin control design of twin pairs who were discordant for living in a state with RCL between 2018 and 2021. The sample consisted of 3,830 adult twins (41% male), including 232 twin pairs discordant for RCL. Problems from alcohol and cannabis use were assessed via the Brief Marijuana Consequences Questionnaire and the Brief Young Adult Alcohol Consequences Questionnaire.Results: Results indicated that the twin living in an RCL state was more likely to endorse past-year cannabis use (OR = 1.56, p = .009), greater number of cannabis use days in the past 6 months (β = 0.47, p = .019), but not more negative consequences from cannabis use (β = 0.21, p = .456) compared to their co-twin in a non-RCL state. There were no differences within-twin pairs in frequency of alcohol use (β=-0.05, p = .601), but the RCL twin reported fewer negative consequences from alcohol use (β=-0.29, p = .016) compared to their co-twin in a non-RCL state. We did not observe any other differences within-twin pairs on other outcomes.Conclusion: These results suggest that living in an RCL state is associated with greater cannabis frequency but not more negative consequences from cannabis use than living in a non-RCL state.

A longitudinal mediational investigation of risk pathways among cannabis use, interpersonal trauma exposure, and trauma-related distress

OBJECTIVE

College students are at high risk for cannabis use, interpersonal trauma (IPT) exposure, and trauma-related distress (TRD). Two phenotypic etiologic models posited to explain associations between cannabis use and trauma-related phenotypes are the self-medication (trauma/TRD → cannabis use) and high-risk (cannabis use → trauma/TRD) hypotheses. The primary objective of the present study was to investigate direct and indirect associations among cannabis use, IPT exposure, and TRD above and beyond established covariates.

METHOD

The current study used data from the first assessment (i.e., baseline survey at Year 1 Fall) and two follow-up assessments (i.e., Year 1 Spring and Year 2 Spring) from an ongoing longitudinal study on college behavioral health. Participants were 4 cohorts of college students (n = 9,889) who completed measures of demographics, substance use, IPT, and TRD. Indirect effects of IPT on cannabis through TRD (i.e., self-medication) and cannabis on TRD through IPT (i.e., high-risk), including tests of covariate effects (e.g., gender, age, race, cohort, alcohol, nicotine), were simultaneously estimated using a longitudinal mediation modeling framework.

RESULTS

Results suggest that more IPT exposure increases risk for TRD and subsequent nonexperimental (use 6+ times) cannabis use, and that experimental (use 1-5 times) and nonexperimental cannabis use increases risk for IPT exposure and subsequent TRD.

CONCLUSIONS

Both the self-medication and high-risk hypotheses were supported. Findings support a bidirectional causal relationship between cannabis use and trauma-related phenotypes. Additionally, results highlight areas for colleges to intervene among students to help reduce cannabis use and create a safer environment. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Recreational Marijuana Legalization, Local Retail Availability, and Alcohol and Marijuana Use and Co-Use Among California High School Students

OBJECTIVE

This study examined whether recreational marijuana legalization (RML) and local retail availability were associated with marijuana and alcohol use and co-use among adolescents.

METHOD

We investigated associations between RML and past-30-day marijuana and alcohol use and co-use, and moderating effects of retail availability of marijuana and alcohol, using data from the 2010-2011 to 2018-2019 California Healthy Kids Surveys (CHKS) of 9th and 11th grade students in 38 California cities. Multilevel mixed-effects logistic regression analyses were conducted, controlling for secular trends and student and city demographics. Additional analyses examined associations of RML and retail availability with co-use among subgroups of drinkers and marijuana users.

RESULTS

For the full sample, RML was inversely associated with alcohol use but was not significantly associated with marijuana use or co-use with alcohol. However, significant interactions between RML and marijuana outlet density showed that there were increases in marijuana and alcohol co-use and alcohol following legalization in cities with higher densities of marijuana outlets. RML was positively associated with co-use among non-heavy and heavy drinkers, but inversely related to co-use among occasional and frequent marijuana users. A significant positive interaction between RML and marijuana outlet density indicated that RML was associated with increases in co-use for occasional marijuana users in cities with higher densities of marijuana outlets.

CONCLUSIONS

RML was associated with increases in marijuana and alcohol co-use and alcohol use among California high school students, particularly those in cities with higher densities of retail cannabis stores, although this varied across alcohol and marijuana use subgroups.

Applying the prototype willingness model to day-level simultaneous alcohol and cannabis use

OBJECTIVE

The prototype willingness model (PWM) provides a framework for understanding simultaneous alcohol and cannabis use by highlighting important psychosocial (e.g., attitudes, norms) predictors of and pathways (via willingness and/or intentions) to simultaneous use. We examined both the PWM reasoned and social reaction pathways in relation to simultaneous use.

METHOD

Eighty-nine young adults self-monitored alcohol, cannabis, and simultaneous use and related constructs for 30 days via daily assessments.

RESULTS

Day-level simultaneous use specific attitudes, norms, perceived vulnerability, intentions, and willingness each predicted simultaneous use, while only day-level intentions and willingness predicted number of negative consequences. We observed significant indirect effects for the two social reaction pathways examined (from descriptive norms to willingness to simultaneous use; from perceived vulnerability to willingness to simultaneous use). Only direct effects were seen for the cognitions in the reasoned pathway; injunctive norms predicted simultaneous use, and attitudes predicted simultaneous use with no mediation by intentions.

CONCLUSIONS

Findings support applying the PWM to event-level simultaneous use among young adults. Future work should establish if PWM day-level constructs are modifiable targets that may be utilized in intervention work focused on reducing simultaneous use and related harms. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

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.

Associations between Alcohol-Free Sources of Reinforcement and the Frequency of Alcohol and Cannabis Co-Use among College Freshmen

Co-use of alcohol and cannabis is common among young adults in the United States. A behavioral economics framework indicates that greater engagement in substance-free sources of reinforcement may be protective against co-use frequency. The current study tested the association between proportionate alcohol-free reinforcement and the frequency of co-use among college freshmen. Participants (N = 86) were freshmen who enrolled in a freshman orientation course and completed surveys at the beginning of the semester. Past month alcohol use, cannabis use, and reinforcement from alcohol-free and alcohol-involved activities were assessed. A zero-inflated Poisson regression was used to test the association between proportionate alcohol-free reinforcement and days of co-use. The results indicated that proportionate alcohol-free reinforcement was negatively associated with co-use days in the count model when controlling for alcohol use days and gender as covariates (β: -3.28, p = 0.016). Proportionate alcohol-free reinforcement did not significantly differentiate individuals who did not engage in co-use in the zero-inflated model (β: -1.68, p = 0.497). The study suggested that greater proportionate alcohol-free reinforcement may be associated with lower engagement in the co-use of alcohol and cannabis among young adults. Increasing engagement in alcohol-free sources of reinforcement may be considered a target for co-use prevention or harm reduction efforts.

Who's at greatest risk? Latent profiles of alcohol and cannabis use and related consequences among college students

BACKGROUND

There is significant heterogeneity in alcohol and cannabis use patterns among college students, with some engaging in use patterns that heighten their risk for adverse consequences. Person-centered approaches can help identify those subgroups of students with riskier use patterns. Latent Profile Analyses (LPA) were conducted to identify subgroups based on alcohol and cannabis use frequency and quantity, to explore demographic covariates and to examine mean differences across subgroups on alcohol- and cannabis-related consequences, simultaneous use, and other substance use.

METHODS

Participants were 2,423 college students (Mage = 20.1; 72  % female) recruited from seven US universities who endorsed past-month alcohol and cannabis use and completed an online survey of substance use behaviors.

RESULTS

A four-profile solution was the best fitting model. Profile 1 represented "light, infrequent alcohol and cannabis use" (73.8 %), Profile 2 represented "heavy, infrequent alcohol and moderate, frequent cannabis use" (15.9 %), Profile 3 represented "moderate, frequent alcohol and cannabis use" (5.6 %) and Profile 4 represented "very heavy, frequent alcohol and heavy, frequent cannabis use" (4.7 %). Students who identify as male, White non-Hispanic, and/or Greek-affiliated were more likely to be in the heavy alcohol use profiles. Profiles 3 and 4 represent high-risk profiles, with both having a higher likelihood of simultaneous use, Profile 3 endorsing more cannabis consequences, and Profile 4 endorsing more alcohol consequences.

CONCLUSION

Results suggest that heavy alcohol or heavy co-use heightens risk for serious adverse consequences.

A qualitative examination of the decision-making process of simultaneous alcohol and cannabis use: Intentions and willingness

BACKGROUND

Alcohol and cannabis use are common among young adults and most young adults who use both substances have used them simultaneously (i.e., using both substances so their effects overlap). Because simultaneous use is associated with a greater number and severity of consequences than single substance use, research is needed to examine the decision-making process of engaging in this high-risk behavior. We conducted a qualitative examination of intentions (i.e., plans) and willingness (i.e., one's openness to engage in the behavior if an opportunity presents itself) to engage in simultaneous use from the perspective of young adults who frequently report this substance use behavior.

METHODS

We recruited 36 young adults who reported simultaneous use and heavy drinking (4+/5+ drinks for women/men; 64% women, ages 18 to 25) to participate in semi-structured interviews. All interviews were double coded for thematic analysis and both novel and a priori themes were found.

RESULTS

Young adults distinguished between intending to engage in simultaneous use and being willing to engage in simultaneous use. They reported that intentions and willingness varied from occasion to occasion. They also reported that context and alcohol consumption influenced their willingness to engage in simultaneous use. Peer pressure or offers increased their willingness to use cannabis while drinking and having current or next-day responsibilities decreased their willingness to engage in simultaneous use. Additionally, planned simultaneous use occasions were characterized as being special events where young adults consumed more substances, but were more likely to monitor their use than unplanned occasions.

CONCLUSIONS

Intentions and willingness may be important proximal predictors of simultaneous use of alcohol and cannabis. Building off this qualitative work, quantitative research should identify which factors influence the decision-making process to engage in simultaneous use and determine when intentions and willingness are most predictive of risky simultaneous use behavior.

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.

Sharing pro-marijuana messaging on social media: The moderating role of legislation

ObjectivesThis study investigates whether recreational marijuana legislation and perceived social norms (descriptive and injunctive) affect college students' propensity to share pro-marijuana messages. We examine which referent group (close friends, typical student, parents) most influence those norms. Participants: A sample of 343 college students participated in the study. Of these students, 214 were from Washington State, where recreational marijuana is legal, and 129 were from Wyoming, where recreational marijuana is illegal. Method: Data, from an online survey, were analyzed through PROCESS analyses. Results: College students in Washington State who believed a typical peer would want them to share pro-marijuana messaging were marginally more likely to share pro-marijuana messages than their counterparts in Wyoming. However, among students who thought a typical peer would not approve of them sharing pro-marijuana messaging, the opposite pattern emerged. Conclusion: Restrictive recreational marijuana legislation does not uniformly abate related message sharing on social media.

Event-level contextual predictors of high-intensity drinking events among young adults

BACKGROUND

Drinking events are characterized by social and physical contexts that are associated with level of alcohol consumption. Ecologically valid data is needed to delineate aspects of the drinking context that are most likely to precipitate excessive alcohol consumption.

METHODS

We utilized event-level data from a longitudinal study that included repeated daily surveys administered in two 28-day bursts. Data from 341 college student past-month alcohol and cannabis users (Mage=19.79; 53 % women; 74 % White) produced a total of 4107 alcohol use days. Generalized linear mixed effects models were used to predict drinking level (moderate: 1-3/1-4 for women/men; heavy-episodic drinking (HED): 4-7/5-9; high-intensity drinking (HID), 8+/10+) by social (e.g., with friends) and physical (e.g., at a party) contexts. We conducted analyses for the first and last drink reported, controlling demographic and study characteristics.

RESULTS

Being at a party, friend's house, or with strangers at the last drink reported were associated with HID compared to HED, while being at home, alone, or with family were protective for HID. No first drink contexts were associated with HID relative to HED. Witnessing others who were intoxicated was consistently associated with HID.

CONCLUSIONS

Social settings such as parties and those with intoxicated persons were associated with risk for HID. The context of drinks at the end of an event are salient signals of level of alcohol consumption. Preventive interventions, particularly those that deliver strategies in real time, should consider accounting for contextual risk factors to reduce harms associated with excessive alcohol consumption.

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).

Using Young Adult Language to Describe the Effects of Simultaneous Alcohol and Marijuana Use: Implications for Assessment

Introduction: Prevalence of alcohol and marijuana use is highest in young adulthood and an increasing number of young adults report simultaneous alcohol and marijuana (SAM) use, which is consistently linked with numerous negative consequences. To better understand reasons for engaging in SAM use and to refine measurement of subjective effects of SAM use, this study aimed to identify (1) how young adults describe subjective experiences during a SAM use occasion and (2) how language describing subjective effects changes as a function of level of alcohol and marijuana use. Methods: Using Amazon's Mechanical Turk (MTurk), 323 participants (53.6% women, 68.4% White, M age = 23.0 years) who reported past-month heavy episodic drinking and past-month SAM use were asked to list words to describe how they feel when using only alcohol, only marijuana, and various combinations of alcohol and marijuana. Results: SAM use language varied as a function of age and substance use behavior but was not associated with sex or race. Large differences in the terms used to describe subjective effects were observed when comparing different combinations of alcohol and marijuana use; most notably the term "cross-faded" appeared primarily when engaging at the heaviest combinations of alcohol and marijuana. Conclusion: Young adults have a wide range of vocabulary for describing subjective effects of SAM use, and subjective effects vary as a function of the level of each substance used. Future research should consider integrating such contemporary language when measuring subjective effects of SAM use.

The anticipated effects of simultaneous alcohol and cannabis use: Initial development and preliminary validation

Social learning theories suggest that outcome expectancies are strong determinants of behavior, and studies find that alcohol and cannabis expectancies are associated with negative substance use outcomes. However, there are no measures to date that assess expectancies for simultaneous alcohol and cannabis use (SAM), often referred to as SAM, despite strong links with negative consequences and rising time trends. The present study sought to provide initial validation of test scores for the Anticipated Effects of Simultaneous Alcohol and Cannabis Use Scale (AE-SAM), using a sample of past month college student simultaneous users (N = 434). Exploratory factor analysis and confirmatory factor analysis conducted in random half samples suggested five expectancy factors, representing high arousal positive, high arousal negative (alcohol driven), high arousal negative (cannabis driven), low arousal positive, and low arousal negative expectancies. The factor structure was invariant across sex, race/ethnicity, and simultaneous use frequency, and demonstrated convergent and discriminant validity with other alcohol/cannabis expectancy measures. AE-SAM high arousal positive expectancies were associated with simultaneous use frequency and heavier drinking/cannabis use, AE-SAM high arousal negative (cannabis driven) expectancies were associated with less frequent simultaneous use and more negative alcohol consequences, and AE-SAM low arousal negative expectancies were associated with less cannabis use. Effects of AE-SAM high arousal positive and high arousal negative (cannabis driven) expectancies remained, above and beyond other expectancy measures, suggesting that AE-SAM expectancies provide additional information beyond single substance expectancies. The results demonstrate the feasibility and utility of assessing simultaneous use expectancies, and lay groundwork for future research on simultaneous use expectancies in relation to alcohol and cannabis couse outcomes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Simultaneous alcohol and marijuana use among college students in the United States, 2006-2019

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US college students’ simultaneous alcohol and marijuana (SAM) use rate was rising.

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There was an upward trend of SAM use among Black college students (2006–2019).

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Hispanic and Asian American/Pacific Islander students’ trend remained stable.

Objective

Simultaneous alcohol and marijuana (SAM) use exposes college students to a myriad of adverse consequences. However, there is no recent nationally representative study on SAM use among college students in the United States (US). To provide an update to the literature, the present study aimed to examine the trends, prevalence, and correlates of SAM use among US college students between 2006 and 2019, using nationally representative data.

Method

We used data from the 2006–2019 National Survey on Drug Use and Health (NSDUH) and the analytic sample was limited to the 55,669 full-time college student respondents (ages 18–22). Using logistic regression analysis, we assessed trends in SAM use prevalence and examined sociodemographic and psycho-social-behavioral correlates of SAM use.

Results

The proportion of US college students who reported SAM use increased significantly from 8.13% (2006–2010) to 8.44% (2015–2019). However, examination by race/ethnicity revealed that the increasing trend was largely driven by Black college students, whose SAM use prevalence increased significantly from 5.50% (2006–2010) to 9.30% (2015–2019), reflecting a 69.09% increase. SAM use rates did not change significantly among other racial/ethnic groups.

Conclusions

This study uncovered an upward trend and prevalence of SAM use among US college students, calling for more research and public health interventions in this area. At-risk subgroups that warrant more attention include college students who are Black, female, above the legal drinking age, have a lower than $20,000 household income, and reside in small metropolitan areas.

Classifying risky cannabis involvement in young adults using the Marijuana Consequences Questionnaire (MACQ)

BACKGROUND

Despite the growing prevalence of cannabis use and associated consequences among U.S. young adults, relatively little is known about precisely what level of marijuana involvement may be problematic.

METHOD

With this study we sought to identify empirically-derived cut-scores for the Marijuana Consequences Questionnaire (MACQ) that would distinguish among levels of cannabis risk in a sample of young adult college students (N = 496). We also examined how these levels of cannabis risk corresponded to a variety of indicators of cannabis involvement, including frequency of use, intoxication, other measures of cannabis consequences, and indicators of more severe cannabis involvement (e.g., physiological dependence, loss of control over use, cannabis use disorder).

RESULTS

Receiver operating characteristic analyses yielded cutoffs that distinguished among three distinct levels of risk, "Low", "Moderate", and "High". These empirically derived cut scores showed strong overall differentiation among classifications, with good sensitivity and specificity. MACQ-based risk levels were validated across several indices of cannabis involvement. Cutoffs differed across genders.

CONCLUSIONS

Findings offer a new application for the MACQ, allowing for the identification of those at greatest risk. As such, this measure may be used to facilitate appropriately targeted intervention.

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.

Are Drinking Cognitions Associated with Marijuana and Concurrent Alcohol and Marijuana Use among Adolescents and Young Adults?

Background

Concurrent use of alcohol and marijuana (i.e., CAM use) is the most common poly-drug use pattern among adolescents and young adults and is associated with negative outcomes. Research indicates that Prototype Willingness Model (PWM) drinking cognitions are associated with alcohol use. This secondary analysis was conducted to explore cross-sectional associations between PWM drinking cognitions, alcohol, marijuana, and CAM use.

Methods

Adolescents and young adults between 15-25 years (N = 124, M age = 18.7) completed a baseline assessment as part of a larger study, including questions on alcohol and marijuana use, and PWM drinking cognitions.

Results

In the social reaction pathway, descriptive norms, perceived vulnerability, and prototype favorability, but not willingness were associated with greater alcohol use, whereas in the reasoned pathway attitudes and intentions were associated with frequency of drinking whereas injunctive norms were not. Both willingness and intention to drink were related to marijuana and CAM use when controlling for alcohol use frequency. Greater willingness to drink was the only significant predictor of marijuana use, and only descriptive norms predicted CAM use. However, of the cognitions within the reasoned pathway, greater attitudes toward drinking and drinking intention were related to greater marijuana and CAM use. Results also indicated that CAM users displayed higher levels of certain risk cognitions than non-users or single substance users.

Conclusions

Findings support and extend the utility of the PWM by indicating that specific alcohol cognitions are associated with alcohol, marijuana, and CAM use in adolescents and young adults.

Joint risk prediction for hazardous use of alcohol, cannabis, and tobacco among adolescents: A preliminary study using statistical and machine learning

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A risk prediction model for hazardous substance use among adolescents is proposed.

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The model predicts risk of hazardous use of alcohol, cannabis, and tobacco jointly.

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It uses statistical and machine learning methods for modeling of multiple outcomes.

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It may help identify adolescent users at elevated risk of hazardous substance use.

For some, substance use during adolescence may be a stepping stone on the way to substance use disorders in adulthood. Risk prediction models may help identify adolescent users at elevated risk for hazardous substance use. This preliminary analysis used cross-sectional data (n = 270, ages 13–18) from the baseline dataset of a randomized controlled trial intervening with adolescent alcohol and/or cannabis use. Models were developed for jointly predicting quantitative scores on three measures of hazardous substance use (Rutgers Alcohol Problems Index, Adolescent Cannabis Problem Questionnaire, and Hooked on Nicotine Checklist) based on personal risk factors using two statistical and machine learning methods: multivariate covariance generalized linear models (MCGLM) and penalized multivariate regression with a lasso penalty. The predictive accuracy of a model was evaluated using root mean squared error computed via leave-one-out cross-validation. The final proposed model was an MCGLM model. It has eleven risk factors: age, early life stress, age of first tobacco use, age of first cannabis use, lifetime use of other substances, age of first use of other substances, maternal education, parental attachment, family cigarette use, family history of hazardous alcohol use, and family history of hazardous cannabis use. Different subsets of these risk factors feature in the three outcome-specific components of this joint model. The quantitative risk estimate provided by the proposed model may help identify adolescent substance users of cannabis, alcohol, and tobacco who may be at an elevated risk of developing hazardous substance 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.

Recreational Marijuana Legalization and Co-use With Alcohol Among Adolescents

INTRODUCTION

Little is known about the possible impacts of recreational marijuana legalization on alcohol and marijuana co-use among underage youth. This study examines the association between recreational marijuana legalization in California in 2016 and alcohol and marijuana co-use among adolescents. Additional analyses investigate the associations between recreational marijuana legalization and co-use among past 30-day drinkers and marijuana users and the frequency of alcohol and marijuana use among co-users.

METHODS

This study used annual cross-sectional data from 7th, 9th, and 11th graders (N=3,319,329) who participated in the California Healthy Kids Survey from 2010-2011 to 2018-2019. Measures included past 30-day alcohol and marijuana use and student demographic characteristics, survey year, pre-post recreational marijuana legalization, and urbanicity. Multilevel regression analyses were conducted in 2021.

RESULTS

Recreational marijuana legalization was associated with greater odds of past 30-day alcohol and marijuana co-use in the total sample (OR=1.06, 95% CI=1.05, 1.07). Recreational marijuana legalization was more strongly associated with co-use among adolescents who reported past 30-day alcohol use (OR=1.58, 95% CI=1.52, 1.62) and heavy drinking (OR=1.25, 95% CI=1.21, 1.29) but was inversely related to co-use among past 30-day marijuana users (OR=0.76, 95% CI=0.74, 0.78). Among past 30-day co-users, there was a positive association with the frequency of marijuana use (β=0.36, SE=0.07).

CONCLUSIONS

Recreational marijuana legalization may increase the risk of alcohol and marijuana co-use among adolescents. Greater restrictions on the numbers of alcohol and marijuana retail outlets and hours of operation and advertising and higher taxes on alcohol and marijuana products may help reduce the availability of these substances to adolescents.

Simultaneous Alcohol and Marijuana Use Among Young Adults: A Scoping Review of Prevalence, Patterns, Psychosocial Correlates, and Consequences

BACKGROUND

Alcohol and marijuana are commonly used by young adults, and use of both substances, particularly at the same time, is prevalent among this population. Understanding the prevalence, patterns, correlates, and consequences of simultaneous alcohol and marijuana (SAM) use is important to inform interventions. However, this literature is complicated by myriad terms used to describe SAM use, including use with overlapping effects and same-day co-use.

OBJECTIVES

This scoping review identifies and describes the peer-reviewed literature focused on SAM use by young adults and distinguishes simultaneous use from same-day co-use of alcohol and marijuana. This review also provides a narrative summary of the prevalence of SAM use, patterns of SAM and other substance use, psychosocial correlates, and consequences of SAM use.

ELIGIBILITY CRITERIA

This review is limited to papers written in English and published in peer-reviewed journals between January 2000 and August 2021. It includes papers assessing simultaneous use or same-day co-use of alcohol and marijuana among young adults ages 18 to 30. Review papers, qualitative interviews, experimental lab studies, policy work, toxicology or medical reports, and papers focused on neurological outcomes are excluded.

SOURCES OF EVIDENCE

PubMed, PsycINFO, and Web of Science databases were searched. Databases were selected and the search strategy developed in consultation with an information specialist.

CHARTING METHODS

A data charting form was utilized to specify which information would be extracted from included papers. Eight categories of data were extracted: (1) research questions and hypotheses; (2) sample characteristics; (3) study procedures; (4) definition of SAM use; (5) prevalence of SAM use; (6) patterns of SAM and other substance use; (7) psychosocial correlates of SAM use; and (8) consequences of SAM use.

RESULTS

A total of 1,282 papers were identified through initial search terms. Through double-blind title/abstract screening and full-text review, the review was narrowed to 74 papers that met review inclusion criteria. Review of these papers demonstrated that SAM use was prevalent among young adults, particularly among those who reported heavier quantities and more frequent use of alcohol and marijuana. Enhancement-related motives for use were consistently positively associated with SAM use. SAM use was associated with greater perceived positive and negative consequences of alcohol and/or marijuana use. Inconsistencies in prevalence, patterns, correlates, and consequences were found between studies, which may be due to large variations in measurement of SAM use, populations studied, methodological design (e.g., cross-sectional vs. intensive longitudinal), and the covariates included in models.

CONCLUSIONS

The literature on simultaneous use and same-day co-use of alcohol and marijuana has expanded rapidly. Of the 74 included papers (61 on SAM use; 13 on same-day co-use), 60 papers (47 on SAM use; 13 on same-day co-use) were published within the last 5 years. Future research focusing on the ways in which SAM use confers acute risk, above and beyond the risks associated with separate consumption of alcohol and marijuana, is needed for understanding potential targets for intervention.

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.

Simultaneous use of marijuana and alcohol: Potential prevention targets among young adults who use alcohol

Simultaneous alcohol and marijuana use (SAM) such that their effects overlap has emerged as a behavior that is riskier than using either substance separately. It has been associated with high-risk binge drinking and driving while intoxicated during young adulthood, and it has been demonstrated to cause greater physical and mental impairment than use of alcohol or marijuana separately. To identify intervention and prevention targets specific to SAM, we examined the relationships between alcohol- and marijuana-specific beliefs and attitudes (risk factors) and self-reported SAM compared to non-simultaneous co-use (CAM) and alcohol use only in the past 30 days in a sample of young adults (n = 1,023, mean age = 23.17; SD = 0.43). Of those who reported drinking alcohol in the past 30 days, 20.7% reported SAM, 12.6% reported CAM, and 66.6% reported using only alcohol. Results from multinomial logistic regression analyses indicated that some marijuana-specific risk factors (e.g., belief that it is not at all wrong for someone their age to use marijuana) differentiated SAM or CAM from alcohol use only, but alcohol-specific risk factors generally did not. However, the perceptions that parents approved of their using marijuana or frequently drinking heavily were associated with a greater likelihood of SAM compared to CAM (OR ranged from 2.25 to 3.53). Findings point to the salience of individuals' attitudes and beliefs around marijuana use and their perception of parental approval of heavy drinking and marijuana use as potential targets for prevention programs targeting risk reduction among young adults.

Young adult concurrent use and simultaneous use of alcohol and marijuana: A cross-national examination among college students in seven countries

Introduction

Many young adults report frequent co-use of alcohol and marijuana, with some individuals engaging in simultaneous use (SAM; use of both substances within the same occasion resulting in an overlap of their effects) and others in concurrent use (CAM; use of both substances during a similar time period [e.g., past 30 days] but not within the same occasion). Emerging work demonstrates that SAM relative to CAM use places individuals at a greater risk for substance-related harms; however, these results primarily rely on U.S. samples. The goal of the present multi-country study was to examine prevalence rates of CAM and SAM use and examine differences in past 30-day SAM/CAM use on alcohol/marijuana substance-related outcomes among college students from seven countries.

Methods

A total of 9171 (70.5% women; Mean age = 20.28, SD = 3.96) college students participated in the cross-sectional online survey study.

Results

Among students who endorsed use of both alcohol and marijuana in the past 30-days (n = 2124), SAM use (75.8%) was far more prevalent than CAM use (24.2%). Moreover, ∼75% of students endorsed SAM use within each country subsample. Regression models showed that SAM vs. CAM use was associated with greater alcohol and marijuana use and negative consequences.

Conclusions

College students from around the world endorse high rates of SAM use, and this pattern of co-use is associated with greater frequency of use and substance-related harms. On college campuses, SAM use should be a target of clinical prevention/intervention efforts and the mechanisms underpinning the unique harms of SAM need to be clarified.

Changes in alcohol use by cannabis use status among adolescents and young adults in the United States: Emerging evidence for both substitution and complementarity

BACKGROUND

The majority of adolescents and young adults (AYA) who use cannabis also use alcohol. Although cannabis use is increasing in the United States (US), it is not known whether the increase contributes to either increased co-use of alcohol and cannabis (e.g., complementarity) or replacement of alcohol with cannabis (e.g., substitution). The current study estimated the prevalence of alcohol use by cannabis use status among US AYA ages 12 to 25 in 2018 and trends in alcohol use by cannabis use status from 2002 to 2018.

METHODS

Data were drawn from the 2002 to 2018 National Survey on Drug Use and Health public use data files. The analytic sample included AYA ages 12 to 25 (2018 sample, n = 26,924; total combined sample 2002 to 2018, n = 576,053). Linear and logistic regression models were used to estimate past-month alcohol use, daily alcohol use, and average quantity of alcohol consumed among AYA with and without past-month cannabis use from 2002 to 2018.

RESULTS

In 2018, any alcohol use and daily alcohol use were significantly more common among AYA who used cannabis use than those who did not use cannabis. Overall, any alcohol use, daily alcohol use, and average drinks per day declined from 2002 to 2018 among AYA irrespective of recent cannabis use. However, the decline in any alcohol use, daily alcohol use, and average alcohol drinks per day was more rapid among AYA who used cannabis (daily and nondaily) than those who did not use cannabis. The rate of decline in average alcohol drinks per day was also higher among AYA with daily compared to nondaily cannabis use.

CONCLUSIONS

Even with declines in alcohol use over time, drinking is much more common among AYA who report cannabis than those without recent cannabis use, which is consistent with complementarity. Yet, because the decline in alcohol use has been more rapid among AYA who use cannabis, there is also evidence of substitution. Thus, the current data on alcohol and cannabis use are consistent with both complementarity and substitution. However, these relationships may change as cannabis legalization expands over time.

The language of subjective alcohol effects: Do young adults vary in their feelings of intoxication?

Among young adults, subjective feelings of alcohol's effects often guide risky decision making. The majority of studies measuring subjective effects have used singular indices ("How drunk do you feel?") which limits our understanding of young adults' full range of subjective states and their individual differences in subjective effects language. Toward a more in-depth understanding of the heterogeneity among alcohol users based on their subjective experiences of alcohol's effects, we identified latent classes of individuals based on their self-generated language describing feelings after drinking and compared these classes across demographic and drinking characteristics. Participants (N = 323, 54% women, 68% White, Ages 18-25 years) were recruited using Amazon's Mechanical Turk (MTurk). Participants listed words they would use to describe how they feel after drinking low, moderate, and heavy amounts of alcohol. Four latent classes of young adults emerged: "happy drinkers" (31%) primarily reported feeling "happy" when drinking; "relaxed drinkers" (24%) reported feeling happy, relaxed, and buzzed; "buzzed drinkers" (18%) reported feeling buzzed and dizzy; and "multiexperience drinkers" (27%) reported feeling buzzed, tipsy, drunk, and wasted. Relaxed drinkers indicated heavier alcohol use and buzzed drinkers reported lower drinking frequency. Classes did not differ by demographic characteristics. Young adult alcohol users can be distinguished based on the language they use to describe their feelings of intoxication. To continue to advance our understanding of subjective effects, it is necessary to take into account the full range of language used and how this language differs by young adult drinking behavior. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Associations between simultaneous alcohol and cannabis use and next-day negative affect among young adults: The role of sex and trait anxiety

BACKGROUND AND AIMS

The simultaneous use of alcohol and cannabis ("simultaneous alcohol and marijuana [SAM] use") is common among young adults and associated with negative substance-related consequences. SAM use may be tied to fluctuating mood states such as negative affect and individual characteristics including trait level of anxiety and sex. However, little is understood about their collective role. In this study, we sought to understand the daily link between SAM use and negative affect and whether this link might differ by both trait anxiety and sex.

METHOD

Participants were 154 young adults (57.8% female, 72.7% White, M age = 20.2) who completed baseline surveys on trait anxiety symptoms and up to 14 consecutive daily surveys on their substance use and affective states.

RESULTS

Multilevel models tested for associations of type of substance use day (i.e., alcohol-only days, cannabis-only days, and no use days relative to SAM use days) with next-day negative affect. Three-way and lower order interactions were tested for substance use day type, anxiety, and sex. Two three-way interactions between cannabis-only days, anxiety, and sex and between alcohol-only days, anxiety, and sex emerged such that SAM use was associated with greater next-day negative affect relative to single substance use days particularly among female participants with elevated anxiety.

CONCLUSIONS

Anxiety and sex are salient factors in the link between SAM use relative to single-substance use and daily negative affect. Study findings reinforce the need to account for all of these factors in order to develop maximally efficacious substance use interventions.

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.

Combined use of alcohol and cannabis: Introduction to the special issue

OBJECTIVE

Combined use of alcohol and cannabis has increased in recent years among certain age groups, and it is well established that individuals who use both alcohol and cannabis (especially if they use both at the same time) are at increased risk for substance-related harms relative to individuals who use only one substance. Far less attention has been placed on the patterns, predictors, and psychological processes associated with alcohol and cannabis co-use, which may inform prevention and intervention programming. Accordingly, this special issue was assembled to advance our understanding of the characteristics and consequences of combined use of alcohol and cannabis.

METHOD

In this introductory article, the Guest Editors present the background for this work and provide an overview of the 14 articles that comprise this special issue.

RESULTS

Studies contained in this special issue capitalize on a variety of methodologies, with a particular focus on investigating typologies of alcohol and cannabis co-use, clarifying motivational and social contexts of co-use, and tracking co-use in daily life via daily diary and ecological momentary assessment designs. Experimental and neuroimaging examinations of co-use are also included. Collectively, the studies generally provide evidence that combined use of alcohol and cannabis is associated with unique characteristics, predictors, consequences, and psychological processes relative to single-substance use.

CONCLUSIONS

The studies in this special issue provide new insight into combined use of alcohol and cannabis. They also highlight a number of promising avenues for future inquiry as the literature on alcohol and cannabis co-use continues to grow. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Unplanned versus planned simultaneous alcohol and marijuana use in relation to substance use and consequences: Results from a longitudinal daily study

Objective: The current study expands the literature on simultaneous alcohol and marijuana (SAM) use by focusing on the distinction between unplanned and planned SAM use to identify potential intervention targets. This study explored whether unplanned or planned SAM use was associated with differences in alcohol and/or marijuana use and consequences. Method: A community sample of young adults (aged 18-25) with recent alcohol and SAM use was recruited [N = 409; mean (SD) = 21.61 (2.17) years; 50.9% female; 48.2% non-Hispanic/Latinx White]. Participants completed five 2-week bursts of online daily surveys (2 ×/day; 81.99% of morning and 82.23% of afternoon surveys completed) and reported on substance use intentions and behavior. Results: Descriptive findings showed that among days on which participants reported SAM use, 41.85% of the days were unplanned SAM use days. Based on daily-level results from multilevel models, on days with unplanned SAM use, young adults reported consuming fewer drinks, fewer hours high from marijuana, and lower subjective intoxication/high, compared to planned SAM use days, thus indicating that planned SAM use was riskier. Unplanned SAM use was not significantly associated with positive or negative consequences related to alcohol or marijuana, after accounting for the number of drinks or hours high from marijuana. Conclusions: Current findings suggest that interventions should target days on which young adults are planning to engage in SAM use. Future work is needed to identify factors that predict planned SAM use on specific occasions and also to disentangle the potential role of unplanned heavy use. (PsycInfo Database Record (c) 2021 APA, all rights reserved).