Patterns of simultaneous and concurrent alcohol and marijuana use among adolescents

Perspectives regarding cannabis use: Results from a qualitative study of individuals engaged in substance use treatment in Georgia and Connecticut

Objective

Cannabis use is increasingly pervasive throughout the U.S. People in treatment for substance use disorders (SUD) may be especially at-risk of harm due to this changing context of cannabis in the U.S. This study's objective was to qualitatively describe experiences and beliefs around cannabis among people who had entered treatment for any SUD in the past 12-months.

Methods

From May to November of 2022, we conducted 27 semi-structured interviews (n=16 in Georgia, n=11 in Connecticut) with individuals in treatment for SUD in Georgia and Connecticut. Interviews were recorded, transcribed, and thematically analyzed using an emergent approach.

Results

All participants had used cannabis in the past. Four themes emerged from the interviews. Participants: (1) perceived cannabis as an important contributor to non-cannabis substance use initiation in adolescence; (2) viewed cannabis as a substance with the potential to improve health with fewer side effects than prescription medications; (3) expressed conflicting opinions regarding cannabis as a trigger or tool to manage cravings for other non-cannabis substances currently; and 4) described concerns related to negative legal, social service, and treatment-related consequences as well as negative peer perception relating to the use of cannabis.

Conclusion

Although participants described cannabis's important role as an initiatory drug in adolescence and young adulthood, many felt that cannabis was a medicinal substance for a range of health challenges. These findings suggest SUD treatment clinicians should address medicinal beliefs related to cannabis among their clients and emphasizes the need for research on cannabis use and SUD treatment outcomes.

The effects of simultaneous alcohol and cannabis use on subjective drug effects: A narrative review across methodologies

Over 75% of young adults who use cannabis also report drinking alcohol, leading to increased risks that include impaired cognition, substance use disorders, and more heavy and frequent substance use. Studies suggest that subjective responses to either alcohol or cannabis can serve as a valuable indicator for identifying individuals at risk of prolonged substance use and use disorder. While laboratory studies show additive effects when alcohol and cannabis are used together, the impact of co-using these substances, specifically with respect to cannabidiol, on an individual's subjective experience remains unclear. This narrative review explores the effects of simultaneous alcohol and cannabis (SAM) use on subjective drug effects, drawing from qualitative research, laboratory experiments, and naturalistic studies. Experimental findings are inconsistent regarding the combined effects of alcohol and cannabis, likely influenced by factors such as dosage, method of administration, and individual substance use histories. Similarly, findings from qualitative and naturalistic studies are mixed regarding subjective drug effects following SAM use. These discrepancies may be due to recall biases, variations in assessment methods, and the measurement in real-world contexts of patterns of SAM use and related experiences. Overall, this narrative review highlights the need for more comprehensive research to understand more fully subjective drug effects of SAM use in diverse populations and settings, emphasizing the importance of frequent and nuanced assessment of SAM use and subjective responses in naturalistic settings.

Feasibility and acceptability of a web-intervention to prevent alcohol and cannabis-impaired driving among adolescents in driver education

Background

Adolescents increasingly view cannabis as a substance with limited harm. Their propensity to engage in risky driving, combined with their relative driving inexperience, places adolescents at heightened risk for harm resulting from impaired driving. Driver education provides an opportunity to help prevent and reduce these risks, yet few interventions address cannabis-impaired driving, especially impairment from simultaneous use of both cannabis and alcohol.

Methods

We adapted a single-session primary care brief intervention (CHAT) for driver education programs. First, we conducted two focus groups with adolescents aged 15-17 years (n = 6; n = 5) enrolled in driver education programs. Their feedback was integrated into a prototype of an online intervention called webCHAT that focuses on preventing alcohol and cannabis-impaired driving. Next, we recruited a new sample of adolescents who user tested webCHAT (n = 8) and provided qualitative and survey feedback. We analyzed qualitative data using classic content analysis and grouped themes according to the feasibility and acceptability of webCHAT.

Results

Participants suggested that webCHAT should have adolescent narrators in short, informal, and interactive videos. In satisfaction surveys (n = 8), 88% of participants would recommend webCHAT to a friend and 88% reported that they learned helpful skills regarding impaired driving. General acceptability was also reflected in interviews (n = 6; 100% would recommend the intervention to a friend, 100% indicated overall positive impressions, and 67% stated it was easy to use). Participants reported that it was helpful to learn about the negative effects of both cannabis and alcohol on driving behavior, voicing that webCHAT would help adolescents make more informed decisions.

Conclusions

Soliciting adolescent perspectives is critical when developing interventions targeting cannabis use because of increasingly permissive attitudes and perceptions of minimal risk associated with use. The current study highlights how feedback can help increase both the feasibility and acceptability of interventions.

Tobacco and alcohol co-use: Lifestyle and sociodemographic factors, and personality aspects as potential predictors in the "Seguimiento Universidad de Navarra" cohort

Tobacco and alcohol co-use are two major lifestyle modifiable risk factors. Understanding the determinants of both behaviors helps to develop interventions to prevent these exposures. However, previous studies have focused on predictors of individual tobacco or alcohol use. This study aims to explore the potential predictors of tobacco and alcohol co-use among Spanish university graduates from the "Seguimiento Universidad de Navarra" (SUN) cohort study. A total of 7175 participants who were co-users of tobacco and alcohol were selected for this cross-sectional analysis. Their mean age was 39.1 years (12.04 SD) and 57.3% were women. Univariate regression models were used to select the potential predictors of tobacco and alcohol co-use, and the areas under the ROC curves (AUC) were calculated. Multivariable logistic regression models were used to create a predictive model. Baseline potential predictors included sociodemographic factors, lifestyle habits, and perceived personality aspects. In the multivariable model, the main significant potential predictors of tobacco and alcohol co-use were driving under the influence of alcohol (odds ratio [OR] = 1.65 [1.43-1.90]), drinking 1-2 cups of coffee daily (OR = 1.50 [1.24-1.84]), drinking three or more cups of coffee daily (OR = 1.61 [1.35-1.91]), and doing more physical activity than recommended (OR = 1.18 [1.02-1.34]) when compared with the reference group. Conversely, those who were married (OR = 0.87 [0.75-0.99], ate at home 7 days a week (OR = 0.69 [0.60-0.80]), or had a high perceived level of competitiveness (OR = 0.83 [0.72-0.95]) had a lower risk of co-use (AUC 0.61 [confidence interval 95% 0.59-0.63]), compared to the reference group. These results could be used by healthcare professionals, especially nurses, to effectively assess patients at higher risk of tobacco and alcohol co-use. [Correction added on 16 February 2024, after first online publication: The abstract section has been revised to provide more clarity in this version.].

Do Subjective Effects from Alcohol and Cannabis Predict Simultaneous Use During a Decision-Making Task?

Background: Simultaneous alcohol and cannabis use is associated with negative outcomes, yet little is known about what motivates the decision of simultaneous use. One possibility is that early-episode subjective effects motivate simultaneous use to complement or replace the first substance's effects. The current study used a hypothetical decision-making task to test this hypothesis. Objectives: College students (N = 486) were presented eight scenarios characterized by alcohol/cannabis subjective effects (i.e., high/low arousal positive [e.g., excited, relaxed], high/low arousal negative [e.g., aggressive, dizzy]) and asked their likelihood of simultaneously using the other substance per scenario. Multilevel modeling tested whether subjective effect scenarios predicted a higher likelihood of simultaneous use and whether ordering moderated this association. Results: Task-based simultaneous use likelihood was associated with self-reported simultaneous use, showing task validity. Scenarios characterized by high/low arousal positive effects were associated with higher likelihood of simultaneous use, whereas high/low arousal negative scenarios were associated with lower likelihood. Alcohol vs. cannabis-first scenarios were associated with higher likelihood of simultaneous use, and significant interactions were observed for high/low arousal positive and high arousal negative effects. High arousal positive scenarios were associated with higher likelihood of simultaneous use when cannabis was used first, low arousal positive scenarios with higher likelihood when alcohol was used first, and high arousal negative scenarios with lower likelihood when cannabis was used first. Conclusions: Beginning-of-episode subjective substance effects may be a promising event-level predictor of simultaneous use, and just-in-time interventions may benefit from targeting the ordering and subjective experiences of alcohol and cannabis use.

Associations between simultaneous use of alcohol and cannabis and cannabis-related problems in 2014-2016: evidence from the Washington panel survey

BACKGROUND

To address the research question of how simultaneous users of alcohol and cannabis differ from concurrent users in risk of cannabis use problems after the recreational marijuana legalization in Washington State.

METHODS

We used generalized estimating equations with a Poisson distribution to analyze the association between simultaneous use of alcohol and marijuana (SAM) and cannabis-related problems compared to concurrent use. The data is a longitudinal sample of drinkers and cannabis users (n = 257, 47% female) aged 18 years and older from Washington State in 2014-2016. We adjusted for survey weights to account for differential probability of selection and response rates. The primary outcome is the past-six-month CUDIT problem subscale (ranging from 0 to 28), which is the total score for seven CUDIT problem items, after excluding the three items that covered marijuana use frequency. Covariates include marijuana use frequency (daily/near daily use, regular use, or infrequent use), marijuana daily quantity, alcohol daily volume, panel survey cycle, medical marijuana recommendation, driving time to nearest marijuana outlet, age of marijuana use onset, and other demographics.

RESULTS

After adjusting for covariates, we found that compared to concurrent use, SAM was significantly positively associated with CUDIT problem subscale (IRR = 1.68, 95% CI: 1.25-2.27, p < 0.001); daily/near daily use of marijuana was strongly significantly associated with CUDIT problem subscale compared with infrequent use (IRR = 5.1, 2.71-9.57, p < 0.001) or regular use (IRR = 3.05, 1.91-4.85, p < 0.001). Secondary analyses using CUDIT total score as the outcome also showed a significant positive association with SAM compared to concurrent use (IRR = 1.17, 1.02-1.34, p < 0.05).

CONCLUSIONS

This study highlighted the importance of SAM, in addition to cannabis use frequency for predicting cannabis-related problems.

Simultaneous Cannabis and Alcohol Use among Medical Cannabis Patients

Background: During the past two decades of cannabis legalization, the prevalence of medical cannabis (MC) use has increased and there has also been an upward trend in alcohol consumption. As less restricted cannabis laws generate more adult cannabis users, there is concern that more individuals may be simultaneously using medical cannabis with alcohol. A few studies have examined simultaneous use of medical cannabis with alcohol, but none of those studies also assessed patients' current or previous non-medical cannabis use. This paper explores simultaneous alcohol and medical cannabis use among medical cannabis patients with a specific focus on previous history of cannabis use and current non-medical cannabis use. Methods: A retrospective cohort study of MC patients (N = 319) from four dispensaries located in New York. Bivariate chi-square tests and multivariable logistic regression are used to estimate the extent to which sociodemographic and other factors were associated with simultaneous use. Results: Approximately 29% of the sample engaged in simultaneous use and a large share of these users report previous (44%) or current (66%) use of cannabis for non-medical purposes. MC patients who either previously or currently use cannabis non-medicinally, men, and patients using MC to treat a pain-related condition, were significantly more likely to report simultaneous alcohol/MC use. Conclusions: Findings indicate that there may be differential risks related to alcohol/MC use, which should be considered by cannabis regulatory policies and prevention/treatment programs. If patients are using cannabis and/or alcohol to manage pain, clinicians should screen for both alcohol and cannabis use risk factors.

Interactive effect of adverse child experiences and suicidal thoughts and behaviors on adolescent alcohol and cannabis use frequency

OBJECTIVE

Adolescents with adverse childhood experiences (ACEs) and suicidality may engage in high levels of substance use to alleviate distress. Most studies of associations among ACEs, suicidality, and substance use rely on retrospective reports by adults. Comparatively less is known about concurrent relationships between ACEs, suicide risk, and substance use in adolescents, which is important for prevention. This study tested if the associations between ACEs and drinking and between ACEs and cannabis use would be even stronger among youth with suicidal ideation or attempt, relative to youth without suicidal ideation or attempt.

METHOD

High schoolers (N = 1,625; 50.8% male; 47.1% female; 2% nonbinary) from western New York completed the Youth Risk Behavior Survey. Ordinal regressions tested main effects and interactions of the number of ACEs and suicidal ideation/behavior (i.e., none, ideation/plan, attempt) on categories of past-month drinking and cannabis days of use, controlling for age, gender, and race/ethnicity.

RESULTS

Significant ACEs by suicide interactions on adolescent drinking indicate that the association between ACEs and drinking was stronger for adolescents with suicide attempt adjusted odds ratio (AOR = 2.63) compared to youth with no ideation or attempt (AOR = 1.56) and suicidal ideation/planning only (AOR = 1.58). Main effects of ACEs (AORs = 1.95-2.08) and suicide attempt (vs. no suicidal ideation/attempt [AOR = 2.11] and suicidal ideation/plan [AOR = 2.11]) were associated with greater cannabis use; interactions were not significant.

CONCLUSIONS

Associations between ACEs and drinking were particularly strong for adolescents with suicide attempt. Conversely, ACEs and suicide attempt were independently associated with cannabis use. Mitigating against ACEs may reduce both adolescent alcohol and cannabis use. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

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.

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.

Subjective effects of simultaneous alcohol and cannabis versus alcohol-only use: A qualitative analysis

OBJECTIVE

Theoretical models of addictive behavior suggest that subjective effects serve as a mechanism through which substance use disorders develop. However, little is known about the subjective effects of simultaneous alcohol and cannabis use, particularly whether simultaneous use (a) heightens specific subjective effects or (b) is related to unique subjective effects relative to single-substance effects. The present study used formative, qualitative data analysis to examine patterns of responses within open-answer text response data on subjective effects of simultaneous use.

METHOD

College students who simultaneously use alcohol and cannabis (N = 443; 68.2% female) were asked to describe how alcohol effects differ on simultaneous alcohol and cannabis use versus alcohol-only use days.

RESULTS

Conventional content analysis revealed nine concepts related to simultaneous (vs. alcohol-only) use subjective effects including as follows: (a) increased/decreased impairment, (b) low arousal/relaxation, (c) balancing/replacement effects, (d) "cross-faded" effects, (e) little-to-no differences, (f) altered sensation and perception, (g) increased negative affective states, (h) increased appetite, and (i) increased/decreased negative consequences. Increased impairment (N = 191) and increased relaxation (N = 110) were the most often endorsed subjective effects, followed by decreased impairment (N = 55), balancing/replacement effects (N = 50) and cross-faded/enhancement effects (N = 44).

CONCLUSIONS

Subjective effects from simultaneous use largely map onto domains of single-substance alcohol and cannabis effects (e.g., relaxation, sociability, cognitive/behavioral impairment), but also include distinct domains related to simultaneous use (e.g., balancing/replacement effects, altered sensation and perception). Future quantitative research is needed to validate measures of subjective effects from simultaneous use and their relations with use behavior. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Cultural and Psychosocial Correlates of co-use among Black-White Biracial Adults

INTRODUCTION

Biracial individuals, a subset of the fastest growing population segment in the United States, frequently experience conflict with ethnic identity, according to marginality theory. Ethnic identity is associated with perceived discrimination and self-esteem, and each of these factors is associated with alcohol and marijuana use. Some research suggests that Black-White biracial individuals have specific challenges with ethnic identity, discrimination, and self-esteem, as well as have disproportionate rates of alcohol and marijuana use separately. Co-use of these substances is linked to more risk behaviors and greater quantity/frequency of use compared to singular use of alcohol or marijuana. However, research examining these cultural and psychosocial factors as correlates of recent co-use among Black-White biracial individuals is limited.

METHOD

The current study examined past-year cultural (i.e., ethnic identity, perceived discrimination) and psychosocial (i.e., age, gender, self-esteem) factors associated with past 30-day co-use (i.e., alcohol, marijuana) among a sample of 195 biracial (Black-White) adults recruited and surveyed via MTurk. We analyzed data using a hierarchical logistic regression.

RESULTS

Results of the final step of logistic regression indicate increases in perceived discrimination were significantly associated with a 1.06 times greater likelihood in 30-day co-use (95% CI [1.002, 1.10]; p = .002). Further, co-use is more common among women than men (OR = 0.50, 95% CI [0.25, 0.98]; p = .04).

CONCLUSIONS

Findings indicate discrimination experienced among Black-White biracial adults is the most culturally relevant correlate of recent co-use in this study, of the factors measured given the framework. As such, substance use treatment with this population may focus on experiences of and coping with discrimination. Since women were also at greater risk for co-use, gender-specific treatments may be beneficial for this population. The article also discussed other culturally relevant treatment considerations.

Experience with dronabinol consumption facilitated a stimulant effect of alcohol and affected alcohol-related changes in frontal cortical endocannabinoid levels in male rats

Combined use of cannabis and alcohol is common in adolescents. However, the extent to which such polydrug exposure affects the brain and behaviors remains under-investigated in preclinical studies. This study tested the hypothesis that combined exposure of Δ-9-tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis, and alcohol will have additive effects on cognitive impairments and altered endocannabinoid levels in the hippocampus and frontal cortex. Male Long Evans rats were provided with daily access to cookies laced with oil or dronabinol, a synthetic THC, during adolescence. Three days after discontinuation of edible THC, the effect of orally administered 3 g/kg alcohol on Barnes maze performance was assessed. The results showed that experience with edible THC facilitated the occurrence of increased moving speed on the maze induced by repeated alcohol administration. However, contrasting to the hypothesis, the combined THC and alcohol exposure did not lead to additive deficits in learning and memory on the Barnes maze. While little effect on endocannabinoid levels was observed in the hippocampus, acute abstinence from alcohol significantly reduced endocannabinoid levels in the frontal cortex. In particular, reduction of N-oleoyl ethanolamine (OEA) and N-stearoyl ethanolamine (SEA) were robust and had an interactive effect with discontinuation from edible THC. These findings add to the scarce literature on THC and alcohol associated changes in endocannabinoid levels and provide insights to future investigations on the roles of OEA and SEA on physiology and behaviors following THC and alcohol co-exposure during adolescence.

Frequency matters: Relations among alcohol and cannabis co-use frequency and alcohol use disorder symptoms in emerging adults

Emerging adult alcohol and cannabis co-use is on the rise and enacts risk for alcohol misuse/alcohol use disorder (AUD). However, few studies have differentiated whether levels of cannabis use (rather than any cannabis use) moderate between-person risk. Considering low-frequency co-users may use both substances via substitution, low-risk/frequency co-use may not enact the same risk for AUD as higher risk co-use. The present study sought to test this assertion. Public access data on emerging adults from the National Study on Drug Use and Health were used (2002-2019; N = 231,681). Participants reported on their past year alcohol use, cannabis use, as well as AUD symptoms. Regression models tested whether levels of cannabis use frequency moderated the association between alcohol use frequency and AUD symptom counts. A significant interaction of cannabis use frequency by alcohol use frequency predicting AUD symptoms was detected. Individuals who co-used alcohol and cannabis reported more AUD symptoms than those who only used alcohol at the same frequency or less. However, co-use was associated with lower AUD symptom counts than alcohol-only use at higher frequency. Findings suggest that all co-users (and alcohol-only users) are not necessarily created equal, and that relations among co-use and risk for AUD symptoms are complex. Rather than a dichotomy of co-users versus alcohol-only users, between-group risk may depend on frequency of both alcohol and cannabis use. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Recreational Cannabis Legalization and Proximity to Cannabis Retailers as Risk Factors for Adolescents' Cannabis Use

Within-person studies are lacking regarding how recreational cannabis legalization (RCL) and the numbers of neighborhood cannabis retailers relate to adolescents' cannabis use. Study participants were 146 offspring (55% girls; 77% White non-Latinx) of men recruited in childhood from neighborhoods with high delinquency rates. Youth were assessed for past-year cannabis and alcohol use one or more times from ages 13 to 20 years (age M[SD] = 16.4 [2.1] years across 422 observations), while they were living in Oregon or Washington from 2005 to 2019 (where cannabis retail stores opened to adults ages 21 years and older in 2014 and 2015, respectively). We calculated distances between addresses of licensed cannabis retailers and participants' homes. Multilevel models that accounted for effects of age on cannabis use did not support that the number of retail stores within 2-, 5-, 10-, or 20-mile radii of adolescents' homes increased likelihood of past-year cannabis use at the within- or between-subjects levels. Likewise, primary models did not support a greater likelihood of cannabis use among youth whose adolescence coincided more fully with the post-RCL period. A secondary model suggested that after adjusting for adolescents' concurrent alcohol use as a marker of general substance use risk, RCL was associated with cannabis use (between-subjects B [95% CI] = .35 [.05-.66], p = .024). Further research is needed with larger prospective samples, at-risk subgroups, and as cannabis markets mature.

Adolescent simultaneous use of alcohol and marijuana by trends in cigarette and nicotine vaping from 2000 to 2020

BACKGROUND

Simultaneous alcohol and marijuana (SAM) use is associated with adverse consequences for youth. While SAM use is overall declining among youth, prior studies indicate increasing marijuana use among US adolescents who ever used cigarettes, suggesting possible moderation of the alcohol-marijuana relationship by cigarette use.

METHODS

We included 43,845 12-th grade students participating in Monitoring the Future data (2000-2020). A 5-level alcohol/marijuana measure was used, including past-year SAM, alcohol-only, marijuana-only, non-simultaneous alcohol and marijuana, or no use. Multinomial logistic regressions estimated associations between time periods (categorized based on sample size: 2000-2005, 2006-2009, 2010-2014, 2015-2020) and the 5-level alcohol/marijuana measure. Models adjusted for sex, race, parental education and survey mode and included interactions of time periods and lifetime cigarette or vaped nicotine use.

RESULTS

While overall SAM among 12th graders decreased from 23.65% to 18.31% between 2000 and 2020, SAM increased among students who never used cigarettes or vaped nicotine (from 5.42% to 7.03%). Among students who ever used cigarettes or vaped nicotine, SAM increased from 39.2% in 2000-2005-44.1% in 2010-2014 then declined to 37.8% in 2015-2020. Adjusted models controlling for demographics indicated that among students with no lifetime cigarette or vaped nicotine use, students in 2015-2020 had 1.40 (95% C.I. 1.15-1.71) times the odds of SAM, and 5.43 (95% C.I. 3.63-8.12) times the odds of marijuana-only (i.e., no alcohol use) compared to students who used neither in 2000-2005. Alcohol-only declined over time in both students who ever and never used cigarettes or nicotine vape products.

CONCLUSION

Paradoxically, while SAM declined in the overall adolescent US population, the prevalence of SAM increased among students who have never smoked cigarettes or vaped nicotine. This effect arises because of a substantial decline in the prevalence of cigarette smoking; smoking is a risk factor for SAM, and fewer students smoke. Increases in vaping are offsetting these changes, however. Preventing adolescent use of cigarettes and nicotine vaped products could have extended benefits for other substance use, including SAM.

Developmental trajectories of alcohol and cannabis concurrent use in a nationally representative sample of United States youths

BACKGROUND

Previous studies have identified common trajectories of single type substance use over the course of adolescence; however, no study to date has examined joint trajectories of cannabis and alcohol concurrent use. Given that expansion of legal cannabis has increased availability, it is important to understand patterns of concurrent use in adolescents and factors that place male and female youth at risk for harmful trajectories of concurrent use. The current study sought to identify joint trajectories of cannabis and alcohol use - and predictors of harmful use trajectories - among male and female adolescents.

METHOD

We used 4 waves of data from 6997 early adolescent participants (age 12-14 years at Wave 1) in the Population Assessment of Tobacco and Health, a nationally representative longitudinal study in the United States. Participants reported their cannabis and alcohol use reassessed yearly for 5 years (2013-2018). We used joint trajectory growth mixture modeling to identify trajectory groups as defined by changes in alcohol and cannabis use over time.

RESULTS

Five classes of alcohol and cannabis concurrent use trajectories were identified. Both internalizing and externalizing symptoms at Wave 1 increased the odds of membership in trajectory groups characterized by more harmful use trajectories. Internalizing symptomatology was a stronger predictor of membership in escalating use trajectories among girls, whereas externalizing symptomatology stronger predictor among boys.

CONCLUSIONS

These findings underscore the utility of jointly considering alcohol and cannabis use when describing common developmental trajectories of use and identifying risk factors for trajectories characterized by harmful use.

Alcohol and cannabis co-use in a national sample of U.S. adults ages 30-80

INTRODUCTION

Growing cannabis legalization has coincided with an increased focus on use of both alcohol and cannabis (AC co-use) among younger people; however, little is known about AC co-use among adults over age 30. This study examines the prevalence of different types of AC co-use among adults, as well as compares AC co-users and alcohol-only users on individual, social network, and neighborhood characteristics.

METHODS

Data come from three annual surveys of a nationally representative sample of 1,770 U.S. adults, initially between the ages of 30-80, conducted between 2019 and 2021. The baseline sample is 52.8 years old on average, 51.8 % female, and 60.1 % non-Hispanic White.

RESULTS

Past month co-use at baseline was reported by 8.4% of adults, and mostly consisted of simultaneous use, with less than 5% of the sample initiating co-use over the two-year follow-up period. Multivariable models indicate AC co-use was cross-sectionally associated with respondents being male, younger, Hispanic (vs White), and having more alcohol use and related problems, and with their social network composition (e.g., having more drinking buddies and cannabis users in the network). However, co-use status was not associated with mental health, physical ailments, or neighborhood quality. Longitudinal analyses indicated that AC co-use at baseline predicted more alcohol use one year later and alcohol related problems two years later among men only.

CONCLUSIONS

AC co-use among adults over age 30 deserves further attention given its prevalence and associations with heavier drinking and related problems. Network-focused interventions may be a promising approach for reducing AC co-use.

Preliminary study of the interactive effects of THC and ethanol on self-reported ability and simulated driving, subjective effects, and cardiovascular responses

RATIONALE

Drug- and alcohol-related motor vehicle accidents are a leading cause of morbidity and mortality worldwide. Compared to alcohol, less is known about the effects of cannabis on driving and even less about their combined effects.

OBJECTIVE

To characterize the combined and separate effects of ethanol and tetrahydrocannabinol (THC) on perceived ability to drive, subjective effects, and simulated driving.

METHODS

In a within-subject (crossover), randomized, placebo-controlled, double-blind, 2 × 2 design, the effects of oral THC (10 mg [dronabinol] or placebo) and low-dose intravenous ethanol (clamped at BAC 0.04% or placebo) on perceived ability to drive, simulated driving (standard deviation of lateral position [SDLP]), subjective effects (e.g., "high"), and physiological effects (e.g., heart rate) were studied in healthy humans (n = 18).

RESULTS

Subjects reported reductions in perceived ability to drive (THC < ethanol < combination) which persisted for ~ 6 h (placebo = ethanol, THC < combination). Ethanol and THC produced synergistic effects on heart rate, significant differences compared to either drug alone on perceived ability to drive and feeling states of intoxication (e.g., high), as well increases in SDLP compared to placebo.

CONCLUSIONS

Perceived ability to drive is reduced under the influence of THC against the backdrop of blood alcohol levels that are below the legal limit. People should be aware that the effects of oral THC on driving may persist for up to six hours from administration. Findings are relevant to the increasingly common practice of combining alcohol and cannabinoids and the effects on driving.

Alcohol and cannabis co-use: Receptiveness to treatments and application to intervention planning

Given the prevalence of alcohol and cannabis co-use among college students, prevention for co-use is crucial. We examined hypothetical receptiveness to substance-specific interventions among students who reported co-use. Students who use alcohol and cannabis were more receptive to alcohol interventions than cannabis interventions. Campus prevention experts should consider offering evidence-based alcohol-focused interventions as a potential pathway for decreasing substance use among college students who engage in co-use.

Study design to evaluate a web-intervention to prevent alcohol and cannabis-impaired driving and use among adolescents in driver education

BACKGROUND

Alcohol and cannabis are the most commonly used substances among adolescents in the U.S. The consequences related to using both substances together are significantly higher relative to use of either substance alone. Teens' propensity to engage in risky driving behaviors (e.g., speeding, rapid lane changes, and texting) and their relative inexperience with the timing and duration of cannabis' effects puts them at heightened risk for experiencing harms related to driving under the influence. Use of alcohol and cannabis peak at age 16, the legal age teens may apply for a provisional driver's license in some states. Targeting novice teen drivers prior to licensure is thus an ideal time for prevention efforts focused on reducing alcohol and/or cannabis initiation, use, and impaired driving.

METHODS

The current study proposes to evaluate the efficacy of webCHAT among 15.5 to 17-year-old adolescents (n = 150) recruited at driver education programs. WebCHAT is a single session online intervention that aims to prevent alcohol and cannabis use and risky driving behaviors. We will recruit adolescents enrolled in driver education programs, and stratify based on whether they used cannabis and/or alcohol in the past 3 months (60% screening negative and 40% screening positive). All participants will receive usual driver education and half will also receive webCHAT. We will test whether webCHAT in addition to usual driver education reduces alcohol and/or cannabis initiation or use and reduces risky driving attitudes and behaviors (intent to drive after drinking/using, riding as a passenger with someone who drank/used) compared to teens in usual driver education over a 6-month period. We will also explore whether variables such as beliefs and perceived norms serve as explanatory mechanisms for our outcomes.

DISCUSSION

The study has the potential to promote public welfare by decreasing adolescent initiation and use of cannabis and alcohol and reducing risky driving behaviors that can have substantial monetary, personal, and social costs. The study recruits adolescents who are at risk for substance use as well as those who are not and it is delivered remotely during a teachable moment when adolescents receive driver education. Trial registration This study was registered with ClinicalTrials.gov on July 13, 2021 (NCT04959461). https://clinicaltrials.gov/ct2/show/NCT04959461.

Characteristics of drinking episodes associated with simultaneous alcohol and cannabis use among underage drinkers in the United States

BACKGROUND

Simultaneous alcohol and cannabis (SAC) use is associated with more negative consequences than independent use of alcohol or cannabis. Contextual characteristics of drinking episodes are associated with the quantity of alcohol consumed and related risk. This study examined whether drinking contexts may also be associated with SAC use.

METHODS

National Survey on Drug Use and Health (NSDUH) 2010-2019 data from past 30-day drinkers aged 12-20 (n = 39,456) were used. A weighted multivariable logistic regression model examined associations between contextual characteristics (alcohol source, number of people, drinking location) and SAC use during their most recent drinking occasion. Models adjusted for survey year, heavy episodic drinking, age, sex, race/ethnicity, student status, and metropolitan area status.

RESULTS

More than one-in-five drinkers reported SAC use. Compared to getting alcohol from parents/family, those who took it from a home (OR = 1.51,95 %CI = 1.24,1.84), got it for free another way (OR = 2.30,95 %CI = 2.05,2.59), paid someone else for it (OR = 2.83,95 %CI = 2.46,3.25), or purchased it themselves (OR = 3.12,95 %CI = 2.66,3.67) had higher odds of SAC use. Compared to drinking alone, drinking with more than one person was associated with higher odds of SAC use (OR = 1.36,95 %CI = 1.12,1.66). Compared to drinking in their home, drinking in a bar (OR = 0.51,95 %CI = 0.41,0.64) had lower odds of SAC use, whereas drinking in someone else's home (OR = 1.12,95 %CI = 1.02,1.22), a car (OR = 1.36,95 %CI = 1.04,1.77), or multiple locations (OR = 1.29,95 %CI = 1.09,1.53) had higher odds of SAC use.

CONCLUSIONS

Findings suggest that alcohol-related contextual characteristics are associated with SAC use among underage drinkers. Laws addressing underage alcohol consumption, including social host liability and sales to minors laws, may also decrease simultaneous cannabis use.

Prescription drug and alcohol simultaneous co-ingestion in U.S. young adults: Prevalence and correlates

Simultaneous co-ingestion of prescription medication (e.g., opioid, tranquilizer/sedative, stimulant) and alcohol is associated with overdose and elevated substance use, but no studies have examined prescription drug misuse (PDM) and alcohol co-ingestion in U.S. young adults (18-25 years), despite the high rates of PDM in this age group. We used the 2015-19 National Survey on Drug Use and Health (young adult N = 69,916) to examine prevalence of past-month PDM-alcohol co-ingestion, PDM characteristics, and sociodemographic, physical health, mental health, and substance use correlates. Logistic regression examined correlates, comparing those without past-year PDM, those with past-year but not past-month PDM, those with past-month PDM without alcohol co-ingestion, and those with past-month PDM and alcohol co-ingestion. An estimated 585,000 young adults engaged in any past-month PDM-alcohol co-ingestion, or between 32.7% (opioids) and 44.6% (tranquilizer/sedatives) of those who were engaged in past-month PDM. Co-ingestion varied by educational status and was more common in males and white or multiracial young adults. All PDM-involved groups had elevated odds of suicidal ideation and other psychopathology, but substance use and substance use disorder (SUD) odds were significantly higher in young adults with co-ingestion, versus all other groups. To illustrate, 41.1% with opioid-alcohol co-ingestion had multiple past-year SUDs, versus 2.0% in those without past-year PDM. Young adults with co-ingestion are particularly likely to have problematic alcohol use and higher rates of SUD. Counseling about the risks of PDM-alcohol co-ingestion and screening for co-ingestion among those at risk are warranted to limit poor outcomes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Alcohol, Marijuana and Other Illicit Drugs Use Throughout Adolescence: Co-occurring Courses and Preadolescent Risk-Factors

This study examined developmental patterns of co-occurrent alcohol, marijuana, and other illicit drugs use during adolescence and the associated preadolescent risk factors in a longitudinal sample of 926 boys from low-socioeconomic, urban neighborhoods. Latent growth mixture modeling revealed six developmental patterns: non-/low-alcohol and non-illicit drug users (61% sample) and five polysubstance user-groups varying in severity based on onset, frequency and type of substances used. In comparisons with non-/low-users, several preadolescent risk factors were associated with increasing severity of polysubstance use. Higher sensation-seeking and lower anxiety were associated with all user-groups. Low self-esteem and family-related risk factors differentiated all user-groups from later-onset users. Higher impulsivity and school problems characterized early-onset and frequent polysubstance users. Impulsive sensation-seekers with lower anxiety and self-esteem cumulated a larger number and higher severity of risk factors and were at risk of early-onset frequent polysubstance use, emphasising the importance of indicated prevention for these high-risk boys.

Age, sex, and race-varying rates of alcohol use, cannabis use, and alcohol and cannabis co-use in veterans vs. non-veterans

BACKGROUND

Military veterans are a high-risk group for health risk behaviors, including alcohol and cannabis use. However, research on veteran vs. non-veteran rates of alcohol/cannabis use are inconsistent across studies. Further, no research has investigated veteran vs. non-veteran rates of alcohol and cannabis co-use, and few studies have tested whether demographic variables, particularly race/ethnicity, moderate group differences. Therefore, the current study tested whether 1) veteran vs. non-veterans differed in rates of alcohol use, cannabis use, and alcohol and cannabis co-use, and 2) whether demographic covariates (age, sex, race/ethnicity) moderated associations.

METHODS

Data on adults (N = 706,897; 53.4% female) were derived from the 2002-2019 National Study on Drug Use and Health. Participant demographics, alcohol use frequency, drinking quantity, and cannabis use frequency were self-reported.

RESULTS

Non-veterans reported higher drinking quantity, cannabis frequency, and co-use. However, being a veteran was a risk factor for heavier drinking for women, ethnic/racial minoritized participants, and adults under the age of 50. Additionally, veteran status was a risk factor for cannabis use frequency in racial/ethnic minoritized participants and women. Similarly, being a veteran was a risk factor for alcohol and cannabis co-use for racial/ethnic minoritized participants, and the buffering effect of being a Veteran on co-use was reduced for older participants and women.

CONCLUSIONS

Results suggest that, at the population level, non-veterans may be heavier alcohol/cannabis users. However, moderating analyses suggested that being a veteran is a risk factor for women, racial/ethnic minoritized individuals, and younger individuals. Findings are discussed in terms of public health implications.

Indirect and direct effects of simultaneous alcohol and cannabis use on alcohol hangovers

INTRODUCTION

Simultaneous use of alcohol and cannabis (i.e., using both on same occasion) is a risk factor for heavier drinking and negative alcohol consequences; however, little research has investigated risk conferred for specific negative consequences. One theoretically relevant negative consequence may be alcohol hangovers; however, no studies have tested cross-sectional or prospective relations between simultaneous use and experiencing alcohol hangovers.

METHOD

The current study (N = 2,964) used public-access data from the National Longitudinal Study on Adolescent to Adult Health (Add Health) to test whether simultaneous alcohol and cannabis use conferred risk for hangover frequency directly or indirectly through heavier drinking. The current study also tested moderated mediation by depressive symptoms, considering simultaneous users have higher levels of depressive symptoms, and depressive symptoms largely mirror those of a hangover.

RESULTS

In a cross-sectional model, simultaneous use was associated with more frequent hangovers both directly and indirectly through heavier drinking. In a prospective model, simultaneous use indirectly predicted more frequent hangovers through heavier drinking; however, the direct path was not significant. None of the paths from simultaneous use to drinking or hangovers were moderated by depressive symptoms in either model.

CONCLUSIONS

The current study suggests that, both concurrently and prospectively, heavier drinking explained significant variance in the relation between simultaneous use and hangover frequency. The significant direct effect of simultaneous use in the cross-sectional model suggests that simultaneous users may have individual characteristics, outside of depressive symptoms, that confer risk for more frequent hangovers above and beyond heavier drinking.

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.

The effects of oral and vaporized cannabis alone, and in combination with alcohol, on driving performance using the STISIM driving simulator: A two-part, double-blind, double-dummy, placebo-controlled, randomized crossover clinical laboratory protocol

The legalization of cannabis for medicinal and non-medicinal purposes, and the corresponding increase in diversity of cannabis products, has resulted an urgent need for cannabis regulatory science. Among the most pressing needs is research related to impairment due to cannabis exposure, especially on driving performance. The present project was designed to evaluate the impact of oral and vaporized cannabis, when administered alone or in combination with alcohol, on simulated driving performance (STISIM driving simulator), cognitive/psychomotor ability, and field sobriety performance. Healthy adults will complete two, double-blind, double-dummy, placebo-controlled, randomized crossover clinical laboratory studies, one with oral cannabis (16 men/16 women) and the second with vaporized cannabis (16 men/16 women). In each study, participants will complete seven experimental sessions during which acute doses of placebo or high Δ9-THC cannabis containing 0, 10, or 25 mg Δ9-THC will be administered both alone and in combination with placebo or alcohol-containing beverages (target breath alcohol concentrations, BAC, of 0.0% or 0.05%). A positive control session (i.e., alcohol at target BAC of 0.08% with placebo cannabis) will also be completed. Simulated driving performance tests (available for download; see Methods), field sobriety assessments, subjective drug effect questionnaires, a mobile device impairment test (DRUID app), and collection of whole blood specimens will be completed repeatedly during each session. Linear mixed models will be used to test for differences across experimental conditions and a priori planned comparisons will be used to determine differences between conditions of interest (e.g., cannabis alone vs cannabis with alcohol). This research is designed to extend prior studies of cannabis and alcohol on driving performance by using oral and vaporized routes of cannabis administration. By increasing understanding of impairment associated with co-use of alcohol and these novel forms of cannabis, this research could inform impairment detection standards for cannabis and alcohol and have important implications for law enforcement, public policy decisions regarding accessibility of these substances, and education of the general population who may use cannabis and/or alcohol. Lastly, this manuscript provides interested researchers with access to the simulated driving scenarios and data extraction tools developed for this study as a means of facilitating future cross-study comparisons, which is important given the heterogeneity in methods used across laboratories in prior research.

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).

Temporal trends in alcohol, cannabis, and simultaneous use among 12th-grade U.S. adolescents from 2000 to 2020: Differences by sex, parental education, and race and ethnicity

BACKGROUND

Simultaneous use of alcohol and cannabis to enhance each other's effect can cause potential harm. Time trends are diverging in adolescent use of alcohol, which is declining, and cannabis, which is increasing among certain subgroups. However, little is known about trends in their simultaneous and non-simultaneous use. Racial and socioeconomic disparities are emerging in cannabis use, which may portend consequences to public health.

METHODS

The 2000 to 2020 Monitoring the Future surveys included approximately 38,000 U.S. 12th-grade students with information on simultaneous use and pertinent demographic factors. A 5-level alcohol/cannabis measure included past-year simultaneous use (i.e., alcohol and cannabis use at the same time), non-simultaneous alcohol and cannabis use, alcohol-use-only, cannabis-use-only, and no use. Multinomial logistic regressions estimated associations (adjusted relative risk ratios; aRRR) with time period (2000 to 2004, 2005 to 2009, 2010 to 2014, 2015 to 2020). Models were adjusted and included interactions with sex, race/ethnicity, and parental education.

RESULTS

Between 2000 and 2020, simultaneous alcohol/cannabis use among 12th graders decreased from 24.4% to 18.7%. From 2015 to 2020 compared to 2000 to 2004, the odds of simultaneous use (adjusted relative risk ratio (aRRR) vs. no use = 0.57, 95% CI [0.50, 0.66]) and alcohol-use-only (aRRR = 0.55, 95% CI [0.49, 0.61]) decreased, while cannabis-use-only odds increased (aRRR = 2.59, 95% CI [1.87, 3.59]). Notably, the prevalence of cannabis-use-only more than doubled from 2011 to 2019. The odds of simultaneous use, alcohol-use-only, and non-simultaneous use of alcohol and cannabis declined more rapidly among males than females, whereas the odds for cannabis-use-only increased faster for females than males. Increases in cannabis-use-only were faster for non-white adolescents.

CONCLUSION

Simultaneous use of alcohol and cannabis is declining among U.S. adolescents, but the decline is slower among females than males. Declines in simultaneous use are largely concomitant with historical declines in alcohol use, indicating that a continued focus on reducing alcohol use among adolescents and young adults has extended benefits to other adolescent substance use. However, cannabis use without any reported past-year alcohol use more than doubled in the last decade, a concerning trend.

A randomized controlled trial of social media interventions for risky drinking among adolescents and emerging adults

PURPOSE

Alcohol use among adolescents and emerging adults is an important public health issue requiring prevention approaches. Herein, we describe outcomes from a randomized controlled trial testing the efficacy of group-based social media interventions targeting risky drinking among youth.

PROCEDURES

Using social media advertisements to screen potential participants, we recruited 955 youth (ages 16-24) reporting recent risky drinking. After completing a baseline assessment, participants were randomized to 8-week secret Facebook group conditions: Social Media Intervention + Incentives for engagement, Social Media Intervention only, and attention-placebo control. Electronic coaches trained in motivational interviewing facilitated interaction in intervention groups. Primary outcomes include past 3-month alcohol use and consequences over 3-, 6-, and 12-month follow-ups. Secondary outcomes include other drug use, consequences, and impaired driving. We also measured intervention engagement and acceptability.

RESULTS

The interventions were well-received, with significantly greater acceptability ratings and engagement in the SMI+I condition relative to other groups. In adjusted analyses, there were no significant differences between interventions and control on alcohol-related outcomes, with all groups showing reductions. Regarding secondary outcomes (70.4% used other drugs), compared to control, the incentivized group reduced other drug use, consequences, and cannabis-impaired driving; the non-incentivized group did not significantly differ from the control condition.

CONCLUSIONS

Among this predominantly poly-substance using sample, findings were mixed, with significant effects of the incentivized social media intervention on drug (but not alcohol) outcomes. Future studies are needed to further refine social media-delivered interventions to reduce alcohol and other drug use.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02809586; University of Michigan HUM#00102242.

Maturing out of alcohol and cannabis co-use: A test of patterns and personality predictors

OBJECTIVE

Reductions in substance involvement into adulthood are thought to represent a normative maturing out of substance use. However, patterns and predictors of maturing out of alcohol and cannabis co-use remain largely unstudied. Therefore, the current study tested developmental trajectories of alcohol and cannabis use from late adolescence into adulthood and whether late adolescent personality traits predicted trajectory class membership.

METHODS

Data come from a longitudinal study of family history of alcohol disorder (N = 458). Age bands were created to model trajectories of drinking quantity, negative alcohol consequences, and cannabis use frequency from late adolescence (age 18-22) to young adulthood (age 23-28) and adulthood (age 29-36). Participants reported on their sensation seeking, conscientiousness, and neuroticism during late adolescence and their typical drinking quantity, negative alcohol consequences, and cannabis use frequency at each age band.

RESULTS

Three trajectory classes were derived from an initial Parallel Process Growth Mixture Model: (1) low-risk maturing out of alcohol-only use, (2) high-risk maturing out of co-use, and (3) high-risk switchers who increased their cannabis use into adulthood. Late adolescent sensation seeking was associated with higher odds of being in both co-use trajectories, whereas a lack of conscientiousness was associated with higher odds of being a co-use switcher.

CONCLUSIONS

We identified heterogeneity in trajectories of co-use, which suggests that a lack of maturing out of alcohol involvement may be accompanied by increased cannabis use. Moreover, late adolescent personality traits may predispose individuals toward riskier developmental trajectories of substance use into adulthood.

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

•

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

•

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

•

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.

A bibliometric analysis of the cannabis and cannabinoid research literature

Background

Cannabis refers to a plant in the family Cannabaceae, which has been used medically, recreationally, and industrially. The last two decades, in particular, have seen a large increase in the volume of literature on this topic. The present bibliometric analysis aims to capture the characteristics of scholarly journal publications on the topic of cannabis and cannabinoid research.

Methods

Searches were run on the Scopus database on April 02, 2021, as follows “(TITLE (cannabi* OR hashish OR marijuana OR marihuana)) AND ( LIMIT-TO ( DOCTYPE,"ar" ) OR LIMIT-TO ( DOCTYPE,"re" ) )”. Results were exported on the same day to prevent discrepancies between daily database updates. Only “article” and “review” publication types were included; no further search limits were applied. The “article” publication type includes publications featuring original research, whereas “review” includes reviews and conference papers. The following data were collected: number of publications (in total and per year), authors, and journals; open access status; publications per journal; journals publishing the highest volume of literature and their impact factors, language of publication; document type; publication country; author affiliations; funding sponsors; most highly cited publications; and most highly published authors. Trends in this subset of publications were identified and presented. Bibliometric networks were constructed using the software tool VOSviewer.

Results

A total of 29 802 publications (10 214 open access), published by 65 109 authors, were published in 5474 journals from 1829 to 2021. The greatest number of publications was published over the last 20 years. The journal that published the largest number of publications was Drug and Alcohol Dependence (n = 705). The most productive countries included the USA (n = 12 420), the UK (n = 2236), and Canada (n = 2062); many of the most common institutional affiliations and funding sponsors originated from these countries.

Conclusions

The number of publications published on the topic of cannabis follows an upward trend. Over the past 20 years, the volume of cannabis research has grown steeply, which can be attributed to a large amount of funding dedicated to researching this topic. Future research should continue to investigate changes in the publication characteristics of emerging research, as the volume of publications on this topic is expected to rapidly grow.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-022-00133-0.

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.

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.

Sex moderates effects of alcohol and cannabis co-use on alcohol and stress reactivity

BACKGROUND

Simultaneous or concurrent use (co-use) of alcohol and cannabis is associated with greater use of both substances over time, academic difficulties, more severe substance use consequences, and adverse impacts on cognitive functioning than the use of a single substance or no substance use. This study examined potential neural mechanisms underlying co-use behaviors in comparison to single substance use. Specifically, we compared alcohol cue reactivity and stress-cue reactivity among individuals who reported frequent same-day co-use of alcohol and cannabis and individuals who reported only alcohol use.

METHODS

The sample included 88 individuals (41 women) who reported only alcohol use and 24 individuals (8 women) who reported co-use of alcohol and cannabis on at least 50% of drinking occasions. All participants completed fMRI stress and alcohol cue reactivity tasks. Because of known sex effects on stress reactivity and alcohol cue reactivity, we tested sex by co-use interactions.

RESULTS

During alcohol cue presentation, co-users had less activation in the thalamus and dorsomedial prefrontal cortex than alcohol-only users, effects that were driven by differences in responses to neutral cues. Examination of stress cue reactivity revealed sex by co-use interactions in the lingual gyrus, with women co-users showing a greater difference between negative and neutral cue reactivity than all other groups. In addition, women co-users had greater connectivity between the nucleus accumbens and both the medial orbitofrontal cortex and the rostral anterior cingulate cortex during negative cue presentation than the other groups.

CONCLUSIONS

These results provide preliminary evidence of enhanced stress cue reactivity in individuals reporting co-use of alcohol and cannabis, particularly women co-users.

A Scoping Review of Gender, Sex and Sexuality Differences in Polysubstance Use in Adolescents and Adults

BACKGROUND

Polysubstance use is a common, problematic behavior that increases risk of harm to self and others. Research suggests that rates may vary based on gender, sex and sexuality. Understanding the current state of this literature may inform prevention and treatment of polysubstance use, leading to reduced public health burden.

OBJECTIVES

This review aimed to synthesize research on gender, sex and sexuality differences in polysubstance use in adults and adolescents.

METHODS

A scoping review was conducted using all EBSCO databases, PubMed and Google Scholar to identify articles examining the effects of gender, sex and sexuality on polysubstance use. Polysubstance use was defined broadly as the use of any combination of substances over any time period and included licit (alcohol, tobacco) and illicit substances, concurrent and simultaneous use, from lifetime to daily use and use at any frequency. Studies were considered if they were published in peer-reviewed journals between January 1990 and October 2020 and were written in English. Publicly available data sources were also utilized to fully capture prevalence data that has not been published elsewhere.

RESULTS

Findings were mostly inconsistent and often conflicting. Only two findings were generally consistent: adult men were overall more likely to report polysubstance use than adult women, and sexual and gender minorities report more frequent polysubstance use than non-minorities.

CONCLUSIONS

Research has been unable to clearly elucidate differences in polysubstance use prevalence and patterns according to gender, sex and sexuality. Several recommendations are offered to advance future research and address limitations of current research.

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.

Patterns of Cannabis and Alcohol Co-Use: Substitution Versus Complementary Effects

PURPOSE

The purpose of this review is to discuss the literature regarding the concurrent use (co-use) of alcohol and cannabis and competing hypotheses as to whether cannabis acts as a substitute for (i.e., replacing the effects of alcohol, resulting in decreased use) or a complement to (i.e., used to enhance the effects of alcohol, resulting in increased use) alcohol. The impact of cannabis use on alcohol-related outcomes has received increased attention in the wake of ongoing legalization of cannabis for both medical and recreational purposes. Evidence for both hypotheses exists in the literature across a broad range of data collection methods and samples and is carefully reviewed here. In addition, various mechanisms by which cannabis may act as an alcohol substitute or complement are explored in depth with the goal of better understanding equivocal findings.

SEARCH METHODS

This review includes articles that were identified from a search for studies on alcohol and cannabis co-use, with a specific focus on studies exploring complementary versus substitution aspects of co-use. Search terms were included in Google Scholar, PsycINFO, MEDLINE, and Web of Science. Eligible studies were those that measured alcohol and cannabis co-use in human samples in laboratory, survey, or ecological momentary assessment studies, or that directly referenced substitution or complementary patterns of use.

SEARCH RESULTS

Search results returned 650 articles, with 95 meeting inclusion criteria.

DISCUSSION AND CONCLUSIONS

Results of this review reveal compelling evidence for both substitution and complementary effects, suggesting nuanced yet significant distinctions across different populations examined in these studies. Several mechanisms for the impact of cannabis use on alcohol-related outcomes are identified, including patterns and context of co-use, timing and order of use, cannabinoid formulation, pharmacokinetic interactions, and user characteristics (including diagnostic status), all of which may influence substitution versus complementary effects. This review will inform future research studies examining this topic in both clinical and community samples and aid in the development of treatment and prevention efforts targeting those populations most vulnerable to negative consequences of co-use. Finally, this review highlights the need for additional research in more diverse samples and the use of mixed-methods designs to examine both pharmacological and contextual influences on co-use.

Adolescent Sibling Associations among Alcohol, Cannabis, and Sexual Risk Behavior: A Test of Interdependence

BACKGROUND

Although siblings are conceptualized as a salient social influence during adolescence, few studies have examined how adolescent siblings influence each other's substance use and risky sexual behavior. Objectives: In this study, we investigated the influence of alcohol use days, cannabis use days, and cannabis and alcohol co-use days on the sexual risk behavior of siblings while accounting for dyadic influence.

METHODS

At the baseline visit for a randomized controlled trial for adolescents referred due to parents' concerns about their substance use ("referred adolescents"; n = 99; M_age=15.95; 38.38% female), we assessed alcohol and cannabis use days as well as sexual risk behavior of the referred adolescents and their sibling (M_age=15.03; 51.52% female). We computed the number of days in the 30 days prior to the baseline that alcohol and cannabis use occurred on the same day. Using a cross-sectional actor partner interdependence model, we tested two models of how adolescents' substance use is associated with their own ("actor effect") and their siblings' ("partner effect") sexual risk behavior-one model for alcohol and cannabis use, and one model for daily co-use.

RESULTS

For referred adolescents and their siblings, within an individual, greater alcohol, cannabis, and daily co-use was significantly associated with sexual risk behavior (actor effects). Furthermore, more sibling co-use days was positively associated with referred adolescent sexual risk behavior (partner effect), representing interdependence.

CONCLUSION

These findings confirm the influence siblings have on one another's risky behavior in adolescence and have implications for prevention and intervention efforts for adolescent substance use.

Adolescent alcohol use predicts cannabis use over a three year follow-up period

Background: Alcohol and cannabis use frequently co-occur, which can result in problems from social and academic impairment to dependence (i.e., alcohol use disorder [AUD] and/or cannabis use disorder [CUD]). The Emergency Department (ED) is an excellent site to identify adolescents with alcohol misuse, conduct a brief intervention, and refer to treatment; however, given time constraints, alcohol use may be the only substance assessed due to its common role in unintentional injury. The current study, a secondary data analysis, assessed the relationship between adolescent alcohol and cannabis use by examining the National Institute of Alcohol Abuse and Alcoholism (NIAAA) two question screen's (2QS) ability to predict future CUD at one, two, and three years post-ED visit. Methods: At baseline, data was collected via tablet self-report surveys from medically and behaviorally stable adolescents 12-17 years old (n = 1,689) treated in 16 pediatric EDs for non-life-threatening injury, illness, or mental health condition. Follow-up surveys were completed via telephone or web-based survey. Logistic regression compared CUD diagnosis odds at one, two, or three-year follow-up between levels constituting a single-level change in baseline risk categorization on the NIAAA 2QS (nondrinker versus low-risk, low- versus moderate-risk, moderate- versus high-risk). Receiver operating characteristic curve methods examined the predictive ability of the baseline NIAAA 2QS cut points for CUD at one, two, or three-year follow-up. Results: Adolescents with low alcohol risk had significantly higher rates of CUD versus nondrinkers (OR range: 1.94-2.76, p < .0001). For low and moderate alcohol risk, there was no difference in CUD rates (OR range: 1.00-1.08). CUD rates were higher in adolescents with high alcohol risk versus moderate risk (OR range: 2.39-4.81, p < .05). Conclusions: Even low levels of baseline alcohol use are associated with risk for a later CUD. The NIAAA 2QS is an appropriate assessment measure to gauge risk for future cannabis use.

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 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 Effects of Alcohol and Cannabis Co-Use on Neurocognitive Function, Brain Structure, and Brain Function

Purpose of review

Given increases in the rates of alcohol and cannabis co-use among adolescents and young adults, this review aims to summarize literature on the effects of alcohol and cannabis co-use on neurocognitive functioning, brain structure, and brain function.

Recent findings

The limited existing studies examining concurrent, recent, and lifetime alcohol and cannabis co-use suggest effects on the brain are likely multifaceted. The majority of studies report that co-use is associated with negative outcomes such as impaired cognitive function and significant alterations in key structural and functional regions of the brain, while others report null effects of co-use compared to non-substance using control and single-substance use groups.

Summary

Current studies lack a general consensus on methodology, definitions of concurrent and simultaneous use, and neuroimaging approaches, which makes it challenging to draw strong conclusions about the effects of co-use. More studies are needed to explore the effects of co-use in the context of simultaneous alcohol and cannabis use.

Cannabis use outcomes by past-month binge drinking status in the general United States population

Cannabis use and binge drinking are increasingly common in the United States, yet little is known about cannabis use patterns among people who engage in binge drinking. This study explored the relationship between several cannabis use outcomes and past-month binge drinking status. Pooled 2015-2018 National Surveys on Drug Use and Health data (N = 226,632) were used to explore the hypothesis that binge drinking is associated with higher prevalence of cannabis outcomes. Cannabis outcomes included past-month and past-year use, daily/almost daily use, and past-year DSM-IV/DSM-5 cannabis use disorder (CUD). Covariates included age, gender, race, total income, and study year. Separate weighted multivariable logistic regressions assessed associations between binge drinking and each cannabis outcome and provided adjusted prevalences of cannabis outcomes by binge drinking status. Past-month binge drinking was positively associated with past-month (OR: 3.72, 95 %CI: 3.56-3.93) and past-year (OR: 3.90, 95 %CI: 3.74-4.06) cannabis use in adjusted regressions. The adjusted odds of DSM-IV and DSM-5 CUD among people who used cannabis were 15 % and 12 % higher among people who engaged in binge drinking than those who did not, respectively (OR: 1.15, 95 %CI: 1.05, 1.26 and OR: 1.12, 95 %CI: 1.03, 1.21). Conversely, the odds of past-month daily cannabis use among people who used cannabis and reported binge drinking was 18 % lower than those who did not (OR: 0.82, 95 %CI: 0.74, 0.91). Our findings provide evidence of associations between binge drinking and cannabis use. Future studies should explore associations between cannabis and other alcohol use behaviors, including heavy drinking, and simultaneous alcohol and cannabis use.

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).

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).