Search

Background: There is significant conflicting evidence as to how using cannabis while drinking alcohol (ie, simultaneous alcohol and cannabis use) impacts alcohol volume consumed, patterns of drinking, and alcohol-related consequences. The impact of simultaneous use on drinking outcomes may be influenced by several within-person (eg, contextual) and between-person (individual) factors., Objective: This study was designed to examine naturalistic patterns of alcohol and cannabis use to understand how simultaneous use may impact drinking outcomes. The primary aims were to understand the following: (1) if simultaneous use is associated with increased alcohol consumption and riskier patterns of drinking, (2) if simultaneous use leads to increased alcohol consequences, and (3) how contextual circumstances moderate the impact of simultaneous use on consumption and consequences., Methods: Data collection involves a 28-day ambulatory assessment protocol in which a sample of non-treatment-seeking young adults who report simultaneous use of alcohol and cannabis complete ecological momentary assessments (random, event-contingent, and time-contingent surveys) of alcohol and cannabis use, contexts, motives, and consequences on their personal smartphones while continuously wearing an alcohol biosensor bracelet. Participants also complete a baseline assessment, brief internet-based check-in on day 14, and a final session on day 28. Community-based recruitment strategies (eg, social media and flyers) were used to enroll 95 participants to obtain a target sample of 80, accounting for attrition., Results: Recruitment and data collection began in May 2021 and continued through June 2024. Initial results for primary aims are expected in October 2024. As of March 2024, the project had recruited 118 eligible participants, of whom 94 (79.7%) completed the study, exceeding initial projections for the study time frame. Remaining recruitment will provide the capacity to probe cross-level interactions that were not initially statistically powered. Strengths of the project include rigorous data collection, good retention and compliance rates, faster-than-expected enrollment procedures, use of a novel alcohol biosensor, and successful adaptation of recruitment and data collection procedures during the COVID-19 pandemic., Conclusions: This is the first investigation to assess the key momentary predictors and outcomes of simultaneous use as well as self-reported and objective (via alcohol biosensor) measures of alcohol consumption and patterns. The results of this study will inform prevention efforts and studies of individuals who use cannabis who are engaged in alcohol treatment., International Registered Report Identifier (irrid): DERR1-10.2196/58685., (©Rachel L Gunn, Jane Metrik, Nancy P Barnett, Kristina M Jackson, Sharon Lipperman-Kreda, Robert Miranda Jr, Timothy J Trull, Mary Ellen Fernandez. Originally published in JMIR Research Protocols (https://www.researchprotocols.org), 25.09.2024.)

Background: The reasons for college students to abstain from alcohol and cannabis use on a given day can inform efforts to prevent or intervene in those behaviors. Research on reasons for alcohol nonuse remains in its nascent stages and no study to date has examined reasons for cannabis nonuse on a given day. Here we examine reasons for nonuse among college students after they planned to use alcohol and/or cannabis., Methods: College students (N = 341; M age  = 19.79; 53% women; 74% White) from 3 universities completed 54 days of data collection across which approximately 50% were nonuse days. Each morning, participants indicated whether they planned to use that day; nonuse reasons were assessed the next morning, if applicable. Generalized linear mixed-effects models were used to disentangle within- and between-person effects., Results: On a given nonuse day (at the within-person level), "work" and "school" were reasons associated with having no plan to use alcohol and "to feel in control" was linked to having no plan to use cannabis. "Did not want to get high" was related to forgoing plans (did not use when originally planned) for alcohol use at the within-person level. At the between-person level, "no desire" was associated with no plans for alcohol or cannabis use and "did not want to get high" was related to no plans for cannabis use. "School" and "could not get" were related to forgoing plans for alcohol and cannabis use, respectively, at the between-person level., Conclusion: An examination of earlier intentions for alcohol and/or cannabis use on nonuse days yielded novel findings on the intention-behavior gap. Reasons for nonuse can inform intervention and prevention strategies (e.g., those involving social norms or just-in-time adaptive efforts) for alcohol and cannabis use on college campuses., (© 2021 by the Research Society on Alcoholism.)

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

Background: Alcohol and marijuana/cannabis are frequently used simultaneously (i.e., SAM use). SAM use is complex, and the ways in which alcohol and cannabis are simultaneously used may reveal differential effects. The purpose of this study was to examine day-level effects of distinct alcohol and cannabis product combinations on simultaneous use and consequences on that day., Methods: College student SAM users (N = 274; 50% women; M age  = 19.82 years) were recruited to complete 54 days of data collection, including 5 repeated daily surveys each day. We identified 12 distinct product combinations reported during SAM-use days. We tested 4 reference groups, with one reflecting the most common use pattern and 3 potentially risky use patterns. We considered 3 outcomes (negative consequences, number of drinks, and number of cannabis uses) and used generalized linear mixed-effects models disentangling within- from between-person effects in all analyses., Results: Using multiple products (≥2) of alcohol was consistently linked to higher odds of experiencing a negative consequence. Combining beer with only one cannabis product (leaf or concentrate) was consistently associated with lower odds of a consequence. Combining cannabis with multiple alcohol products was associated with heavier alcohol consumption. Using dual cannabis products also was associated with heavier cannabis consumption, but this pattern was not significantly different than using concentrate only on a given day., Conclusion: This is the first study to examine day-level influences of distinct alcohol and cannabis product combinations on consumption and consequences among young adult SAM users. Findings suggest that mixing alcohol products confers greater risk for negative consequences and heavier consumption, whereas there is little difference in cannabis consumption when using concentrate only vs. 2 cannabis products on a given day, except for concentrate + beer. Our findings support existing protective strategies of not mixing alcohol products and avoiding use of cannabis concentrate for SAM use as well., (© 2020 by the Research Society on Alcoholism.)

Background: Alcohol and marijuana are frequently co-used with overlapping effects. However, the absence of consistent operational definitions delineating simultaneous alcohol and marijuana use (SAM) from concurrent use (CAM) challenges consistent inferences about these behaviors. This study first examined whether daily alcohol and marijuana co-use predicted substance-use related consequences and subjective intoxication; and then evaluated whether competing operationalizations of SAM and CAM were associated with differences in these outcomes on co-use days., Methods: A sample of 341 young adult college students who reported past-month use of both alcohol and marijuana "at the same time so that their effects overlapped" completed a two-wave survey with paired 28-day daily experience sampling bursts examining alcohol and marijuana co-use. Outcomes were (a) daily substance-use related consequences; and (b) daily subjective intoxication. Focal predictors were daily drinks and marijuana uses; daily co-use versus single-substance use (Aim 1) or CAM versus SAM (Aim 2); and their interaction., Results: Participants reported more negative consequences on co-use days versus marijuana-only days and greater subjective intoxication relative to alcohol or marijuana-only days. Competing operationalizations of SAM, defined as daily co-use occurring within 1-240 min in increments of 1 min, found no difference in consequences or subjective intoxication regardless of operationalization., Conclusion: Co-use days involve greater risk than alcohol-only or marijuana-only days. Although there was no evidence of additional daily risk from simultaneous use regardless of the timeframe used to operationalize it, investigating these effects remains challenging due to the generally small timeframe between substances on co-use days in this sample., Competing Interests: Declaration of Competing Interest There are no conflicts of interest to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Historically, cannabis researchers have assumed a single mode and product of cannabis (e.g., smoking plant). However, patterns of use, products (e.g., concentrates, edibles), and modes (e.g. blunts, vaporizers) are diversifying. This study sought to: 1) classify cannabis users into groups based on their use of the full range of cannabis products, and 2) examine user group differences on demographics, cannabis consequences and cannabis use disorder (CUD) symptomatology., Methods: In a sample of college students (data collected in Fall 2017), who used cannabis in the past year (N = 1390), latent class analysis (LCA) was used to characterize cannabis users. We then added demographic characteristics, cannabis consequences, and CUD symptomatology scores separately to LCA models to examine class differences., Results: Five unique classes emerged: high-frequency all-product users, high-frequency plant/moderate-frequency edible and concentrate users, low-frequency plant users, moderate-frequency plant and edible users, and low-frequency edible users. Demographic characteristics, cannabis consequences, and CUD symptomatology differed across classes characterized by frequency as well as product., Conclusions: Results reflect the increasing variety of cannabis products, modes, and use patterns among college students. In this sample, frequency of use remains a strong predictor of cannabis-related consequences, in addition to type of product. As variation in cannabis use patterns continue to evolve, it is essential for researchers to conduct comprehensive assessments., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

College entry is associated with marijuana initiation, and co-use of alcohol and marijuana is associated with problematic outcomes, including alcohol-related consequences. The present study explored if: (a) use of marijuana on a given day would be associated with greater alcohol use within the same day; (b) use of marijuana within a given week would be associated with increased alcohol-related consequences in that same week; and (c) the association between marijuana use and alcohol consumption and consequences varies across time or by precollege level of problematic alcohol use. Participants (N = 488 college student drinkers, 59% female) completed assessments of marijuana use, alcohol use, and alcohol consequences across 2 years. Analyses revealed: (a) daily marijuana use predicted greater number of daily drinks and estimated breath alcohol concentration; (b) weekly marijuana use predicted more weekly positive and negative alcohol consequences; (c) the effect of daily marijuana use on alcohol use strengthened over time, while the effect of weekly marijuana use on positive alcohol consequences reduced over time; and (d) precollege level of problematic alcohol use moderated the association between daily marijuana and alcohol use and weekly marijuana use and negative consequences. This study provides the first longitudinal evidence of the association between marijuana use and greater alcohol use and consequences in college students. Future research examining event-level measurement of alcohol and marijuana co-use is important for the prevention of alcohol-related consequences. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Background: The study aims were to examine daily associations between marijuana and alcohol use and the extent to which the association differs as a function of cannabis use disorder (CUD) and/or alcohol use disorder (AUD) diagnosis., Methods: Timeline Followback interview data was collected in a study of veterans (N = 127) recruited from a Veterans Affairs hospital who reported at least 1 day of co-use of marijuana and alcohol in the past 180 days (22,860 observations). Participants reported 40% marijuana use days, 28% drinking days, with 37% meeting DSM-5 criteria for CUD, 40% for AUD, and 15% for both. Use of marijuana on a given day was used to predict a 3-level gender-adjusted drinking variable (heavy: ≥5 (men)/4 (women) drinks; moderate: 1 to 4/3 drinks; or none: 0 drinks). A categorical 4-level variable (no diagnosis, AUD, CUD, or both) was tested as a moderator of the marijuana-alcohol relationship., Results: Multilevel modeling analyses demonstrated that participants were more likely to drink heavily compared to moderately (OR = 2.34) and moderately compared to not drinking (OR = 1.61) on marijuana use days relative to nonuse days. On marijuana use days, those with AUD and those with AUD + CUD were more likely to drink heavily (OR = 1.91; OR = 2.51, respectively), but those with CUD were less likely to drink heavily (OR = 0.32) compared to moderately, nonsignificant differences between any versus moderate drinking in interaction models., Conclusions: Heavy drinking occurs on days when marijuana is also used. This association is particularly evident in individuals diagnosed with both AUD and CUD and AUDs alone but not in those with only CUDs. Findings suggest that alcohol interventions may need to specifically address marijuana use as a risk factor for heavy drinking and AUD., (Copyright © 2018 by the Research Society on Alcoholism.)