Alcohol and cannabis use among college students: Substitutes or complements?

Does cannabis substitute or complement alcohol after recreational cannabis legalization in the Washington State? A three-level mixed-effects modeling

BACKGROUND

Whether cannabis substitute or complement alcohol remains inconclusive. Little is known about the daily-level associations between cannabis and alcohol use by cannabis user type (medical vs. recreational use) in people who use alcohol and cannabis within a legalized environment.

METHODS

Adult participants were from four waves of Washington Panel Survey during 2014-2016, who consumed both cannabis and alcohol in the past six months. Daily measurements of alcohol and cannabis use in the past week were collected at each wave. Our outcome variable was continuous alcoholic drinks, the exposure was any cannabis use. We applied three-level negative binomial models to account for within-person wave-to-wave and between-person variations, deriving pure within-person within-wave associations between cannabis and alcohol use at the daily level. A cross-level interaction between day-level cannabis use and wave-level medical cannabis recommendation investigated the potential differential substitution/complementarity patterns by medical recommendation status.

RESULTS

259 respondents with 440 person-waves and 3,051 daily observations were included. We found a statistically significant pure Level 1 (within-person daily-level) effect of cannabis use among recreational cannabis users (IRR = 1.37, 95 % CI: 1.05-1.79, p = 0.02), showing a complementary use pattern. We also found a statistically significant cross-level interaction between medical cannabis recommendation and cannabis use at Level 1 (IRR = 0.57, 95 % CI: 0.34-0.96, p = 0.03), indicating that, differently from recreational users, medical cannabis users may have a substitution use pattern.

CONCLUSIONS

Cannabis user type may inform co-use patterns. This study suggested recreational cannabis users tended to use alcohol and cannabis in a complementary manner in Washington State following the legalization of recreational use.

Is there a relationship between abuse of alcohol and illicit drugs seen in hair results?

Combined use of alcohol and illicit drugs is a serious health and social problem. In this study, it was examined, whether a relationship between alcohol and drug abuse can be ascertained by comparison of alcohol marker and drug concentrations in hair. In the frame of a social support system for families with parental abuse of illicit drugs, hair samples were analyzed between 2011 and 2022 for methadone, heroin (6-acetylmorphine), cocaine, amphetamine, ecstasy (MDMA), cannabinoids (THC), and the alcohol markers ethyl glucuronide (EtG) and ethyl palmitate (EtPa). For 1314 hair samples from adolescent and adult family members, the hair results show a prevalence of combined occasional or regular drug use and social or abusive alcohol use of 41%-60% except heroin (35%). The drug concentrations were statistically compared in the three categories of abstinence or moderate drinking, social drinking, and alcohol abuse. For the most frequently detected drug cocaine (n = 703), a significant increase of the concentrations with rising alcohol consumption was found. The frequent detection of cocaethylene proved the preferred simultaneous intake of both substances. For THC (n = 489), no significant difference between the alcohol consumer groups was seen. Concerning the less frequently detected methadone (n = 89), 6-acetylmorphine (n = 92), amphetamine (n = 123), and MDMA (n = 105), no clear trend between drug and alcohol marker results was determined. It is concluded that the evaluation of hair results is an appropriate way to study the extent of combined drug-alcohol consumption and complements other studies based on acquisition of consumption data by interview or questionnaire.

Order of Cannabis and Alcohol Use on Pregaming and Non-Pregaming Days Among College Students

OBJECTIVE

Pregaming is common among college students and is associated with heavy drinking and negative alcohol-related consequences. The use of cannabis on pregaming days may exacerbate negative alcohol-related consequences, and the ordering of when cannabis is used on these days may buffer against or intensify these consequences. Considering the growing rates of simultaneous use of cannabis and alcohol among college students, it is necessary to examine the role of pregaming behaviors in the context of cannabis use and its effects on alcohol-related consequences.

METHOD

In the present study, college students (N = 485) completed a baseline survey and 14 days of daily surveys, reporting on daily alcohol and cannabis use and alcohol-related negative consequences. Multilevel structural equation models were fit to evaluate cannabis outcomes on pregaming versus non-pregaming drinking days and ordering effects on alcohol-related consequences, controlling for number of drinks, age, and sex.

RESULTS

Across all drinking days, pregaming on that day as well as cannabis use during drinking on that day were associated with a greater risk for alcohol-related consequences. On days that did not involve pregaming, the use of cannabis before drinking was associated with a greater risk for negative alcohol-related consequences, whereas cannabis use after drinking was associated with less risk for consequences. These effects were observed on non-pregaming days only and not on days with pregaming.

CONCLUSIONS

Findings have implications for brief interventions with students, as analyses suggested that both cannabis use and pregaming--independent of number of drinks consumed--are risky behaviors associated with alcohol-related consequences.

Latent profile analysis of college students' alcohol and cannabis co-use patterns after recreational cannabis legalization

OBJECTIVE

Evidence is mixed on how young adults' cannabis and alcohol use and co-use patterns have changed following recreational cannabis legalization (RCL). Incorporating measures of frequency and intensity of use we examined changes in college students' use and co-use patterns following RCL.

METHOD

Four-year college students (n = 845,589) ages 18-24 years participated in the National College Health Assessment between 2008 and 2018, including students from 7 states that enacted RCL and 42 that did not. Latent profile analyses identified six patterns of use from four indicator variables tapping frequency of cannabis use and frequency and intensity of alcohol use: Abstainers, Light Alcohol Only, Heavy Alcohol Only, Predominantly Heavy Cannabis Use, Moderate Co-use, and Heavy Co-use.

RESULTS

Regression models that adjusted for time and person- and institution-level covariates indicated that students' exposure to RCL was associated with lower odds of being in the two alcohol-only use classes, higher odds of being in the Predominantly Heavy Cannabis Use, Heavy Co-Use and Abstainers classes, and was not significantly related to Moderate Co-Use class membership.

CONCLUSIONS

RCL was positively associated with patterns of frequent cannabis use and frequent and intense co-use but also with abstinence. Use of alcohol-only became less prevalent after RCL. Research on how RCL influences the prevalence of problematic patterns of substance use will inform and improve prevention efforts.

Cannabis donation as a harm reduction strategy: a case study

BACKGROUND

The United States (US) continues to experience unprecedented rates of overdose mortality and there is increased need to identify effective harm reduction practices. Research from Canada describes cannabis donation through harm reduction agencies as an adjunctive strategy to mitigate the negative consequences of more harmful drugs. This case study describes the operational logistics, feasibility, and potential benefits of a cannabis donation program that was operated through a harm reduction program in rural Michigan.

CASE PRESENTATION

We applied a community driven research approach to gather information from harm reduction program staff about the implementation and evolution of cannabis donation efforts in Michigan. We also examined 20-months (September 2021 through May 2023) of administrative data from a cannabis company to compare the sale and donation of cannabis products. Ten cannabis-experienced harm reduction clients received cannabis donations, with clinical staff determining client interest and appropriateness, and providing weekly pick-up or delivery. To expand product availability and sustainability, we examined administrative data from a commercialcannabis company that volunteered to provide donations. This administrative data suggests that while flower products constitute most of the adult and medical sales, edible, oil, and topical products predominated donations. Further, cost analysis suggests that donations represent only 1% of total gross sales and account for much less than the expected yearly donation amount.

CONCLUSIONS

Research suggests there is potential to reduce alcohol and drug use related harms of more dangerous substances through substitution with cannabis. This case study is the first to document cannabis donation as a harm reduction practice in the US and suggests potential for sustainability dependent on state laws. Findings from this case study provide a starting point for inquiry into cannabis donation as a harm reduction strategy in the US; future research is needed to fully understand the individual-level outcomes, public health impacts, necessary legal regulations, and best practices for cannabis donation programs through harm reduction organizations.

A 2-year follow-up of the effects of combined binge drinking and cannabis consumption on academic performance and adjustment in Spanish third-year university students

Introduction

The study was based on 2-year follow-up of the effects of binge drinking and cannabis co-consumption on academic performance and adjustment in Spanish Third-Year University Students and to further explore the impact of academic adjustment on this relationship.

Methods

A total of 144 students (aged 19-20 years) enrolled in the third year of university completed the study. The students were recruited during in first academic year (T1) via a survey that included items regarding the use of alcohol (AUDIT-C), cannabis and other drugs and demographic variables. Then, participants meeting the study criteria were then selected and invited by e-mail to a clinical (face-to face) structured interview. The participants completed a calendar of alcohol consumption during the 6 months prior to the interview (Alcohol Timeline Follow back), and recorded cannabis consumption in 3 months prior to the interview. To examine the effects of alcohol and cannabis co-consumption on the outcome variables, we categorized participants into three consumption groups (i.e., control, BD, and BDCA) based on the number of BD days and cannabis unit scores.

Results

Binge drinking and cannabis co-consumption in first-year students was significantly associated with poor academic performance and adjustment after 2 years of undergraduate study. Relative to controls, co-consumers (BDCA) reported significantly lower academic and personal-emotional adjustment to university as well as poorer performance. Mediation analysis showed that academic adjustment explains the mechanism by which BDCAs perform less well, mediating the relationship between co-consumption and academic performance, with an indirect effect representing 64.61% of the total effect. Furthermore, the mediating effect of academic adjustment was maintained after controlling for academic adjustment and baseline grade point average (T1).

Conclusion

This prospective follow-up study helps to further our knowledge of how combined binge drinking and cannabis consumption may affect university adjustment and academic success in Spanish university students Overall, the study results should encourage health professionals, educational psychologists and academic institutions to take ownership of the need for support and involvement in prevention, as well as for provision of guidelines for implementing appropriate intervention strategies.

The Alcohol and Polysubstance Behaviors of Mandated College Students Prior to Collegiate Sporting Events: An Assessment of Pregaming

Background: Despite a litany of education and prevention efforts seeking to curtail alcohol and other drug (AOD) use behaviors of United States (U.S.) college students, AOD use remains pervasive among the American college student population. Socio-cultural reinforcement of AOD behaviors, such as pregaming (PG), are often considered normative aspects of the collegiate experience, potentially introducing, and/or exacerbating, AOD use among U.S. college students. Objective: Due to the unique relationship PG has with the U.S. college experience and sports culture, this study explored the relationship between PG prior to a live sporting event and frequency of alcohol use, and the likelihood of persons who pregame also engaging in polysubstance use (>1 substance during drinking/use event). Methods: This study was conducted with college students (n = 816) attending a large public university in the Southeastern Conference (SEC) who violated campus alcohol use policies. Results: Beyond the influence of important demographic covariates, PG (p < .001) was significantly associated with a greater frequency of alcohol use. Moreover, students who participated in PG festivities were nearly 2.5 times more likely to participate in polysubstance use. Discussion: PG prior to live collegiate sporting events has clear public health and policy implications. Future efforts should institute and enforce risk-management policies on college campuses and employ event-specific alcohol and polysubstance use prevention and intervention strategies.

How Does Being under the Influence Affect Willingness to Experience Overlapping Effects of Alcohol and Marijuana?

OBJECTIVE

This study tested how individuals anticipate they will respond to opportunities to engage in simultaneous alcohol and marijuana (SAM) use.

METHODS

Two studies utilizing a within-subjects design were conducted. Study 1 was conducted in Spring 2021 and a replication (Study 2) was conducted in Fall 2021. Participants were presented with pairs of scenarios. One scenario pair compared how willing participants expected to be to get drunk if they were sober vs. high. Another pair compared how willing participants would be to take a hit of marijuana if they were sober vs. drunk. College attending young adults (Study 1: N = 173; female = 81%; Study 2: N = 212; female = 49.1%) with varying degrees of substance use experience were recruited.

RESULTS

In Study 1 participants reported greater willingness to get drunk when sober than when high. This was qualified by a statistically significant interaction whereby differences were greater among those who had more experience with past 30-day heavy drinking. Similar findings emerged for willingness to use marijuana. Participants anticipated greater willingness to use marijuana when sober than when drunk. This was also qualified by a statistically significant interaction whereby differences were greater among experimental or established users of marijuana than among abstainers. Study 2 findings replicated those from Study 1.

CONCLUSIONS

College attending young adults state greater willingness to remain under the influence of one substance than to engage in SAM use when opportunities arise. Simultaneous use of alcohol and marijuana among college students is likely an exception, not the rule. Implications for prevention are discussed.

Ratings of executive function as a risk factor for adolescents' frequent cannabis use: A prospective longitudinal study

OBJECTIVE

We examined the extent to which behavioral ratings of children's executive function (EF) in early adolescence predicted adolescents' cannabis use, and whether associations were independent of parents' cannabis and alcohol use and adolescents' alcohol use.

METHOD

Participants were 198 offspring (44% boys) of 127 mothers and 106 fathers. Parents and teachers completed the Behavior Rating Inventory of Executive Function (BRIEF) at ages 11-14 years. Youth were interviewed repeatedly from ages 14 to 20 years regarding frequency of cannabis and alcohol use. Two-level models regressed dichotomous cannabis outcomes (annual, weekly, or daily use) on age at the within-person level and the random intercept of cannabis use on EF, parent substance use, and covariates (age 7 IQ indicators, child gender, parent education, and mean of ages assessed) at the between-person level.

RESULTS

Poorer child EF predicted significantly (p < .05) higher likelihood of weekly (b[SE] = .64[.24]) and daily (b[SE] = .65[.25]), but not annual (b[SE] = .38[.22]), cannabis use. Parent cannabis use (b[SE] = .53[.25] to .81[.39], p < .05) independently predicted all three outcomes, and effects were distinct from those explained by parent alcohol use (b[SE] = .66[.29] to .81[.35], p < .05). EF remained a significant predictor of weekly and daily cannabis use after adjusting for parental alcohol and cannabis use, and adolescents' alcohol use.

CONCLUSIONS

Children exhibiting poorer EF were more likely to use cannabis weekly and daily in later adolescence. Whereas literature suggests poorer EF may be a consequence of cannabis use, these findings suggest EF should be considered prior to cannabis use initiation. EF during childhood may be a fruitful prevention target. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Associations between alcohol and cannabis use order, frequency, quantity, and consequences in a college sample of individuals who co-use alcohol and cannabis

BACKGROUND AND OBJECTIVES

Using both alcohol and cannabis (either at the same time or at different times) is common among college students, and is called "co-use." Using these substances simultaneously, such that their effects overlap, is thought to be an especially risky co-use pattern. Gaining a better understanding of how co-use patterns relate to substance use and consequences could aid prevention and intervention efforts.

METHODS

We examined college students (N = 401) who reported using both alcohol and cannabis at least once in the past 30 days. Path analysis was used to explore relations among co-use patterns (number of days in a typical week that participants used both alcohol and cannabis; the number of days using alcohol first, cannabis first, alcohol last, and cannabis last; the number of days of simultaneous use), past-30-day alcohol and cannabis consequences, use frequency, and typical quantities used.

RESULTS

Each additional day of using alcohol first was associated with fewer past-30-day cannabis consequences. Each additional day of using cannabis first was associated with fewer alcohol-related consequences. Each additional day of using alcohol and cannabis on the same day and each additional day of simultaneous use were both associated with less cannabis used and alcohol consumed in a typical week.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

This study is among the first to identify associations between alcohol and cannabis order and outcomes (i.e., consequences and consumption). Results suggest that modifying which substance is used first on a given day could be a practical intervention strategy for individuals who co-use alcohol and cannabis.

Changes in secondary substance use after the onset of the COVID-19 pandemic among people who use cannabis: Findings from a web-based sample of adults in the United States

The coronavirus disease 2019 (COVID-19) pandemic has had widespread impacts on mental health and substance use. Increases in cannabis use have been documented in the United States, but little is known about how other substance use has changed among people who use cannabis. We sought to examine changes in alcohol, tobacco, opioid, and stimulant use during COVID-19 and explore how these changes relate to patterns of cannabis use. Data were obtained from a web-based survey of adults in the United States who use cannabis (n = 1,471) administered in September 2020. Using data reported in retrospective (prepandemic) and time-of-survey assessment periods, we explored changes in the prevalence of regular (≥ weekly) alcohol, tobacco, opioid, and stimulant use during COVID-19 among respondents who used medical and nonmedical cannabis. We used modified Poisson regression to examine cannabis-related correlates of increasing or decreasing secondary substance use during the pandemic. There was a slight but significant increase in ≥weekly alcohol use in the medical use group only (41.4%-47.0%, p = .034). ≥ Weekly tobacco, opioid, and stimulant use did not change significantly. Pandemic-concurrent shifts in secondary substance use depended on interacting cannabis-related factors including medical cannabis use, prepandemic cannabis frequency, and pandemic-concurrent frequency changes. For example, ≥ weekly prepandemic cannabis use was significantly and positively associated with decreasing opioid use frequency among the medical cannabis use group only. Assessments of the pandemic's effects on substance use should consider relationships between cannabis and other substances, which may differ according to cannabis-specific behaviors, motives, and contexts of use. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Relationships between sales of legal medical cannabis and alcohol in Canada. Health Policy 2023;128:28-33. [PMID: 36443110 DOI: 10.1016/j.healthpol.2022.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The extent to which legalizing cannabis use might lead to increased or decreased alcohol use has important implications for public health, economic growth, and government policy. This study analyzed Canada's monthly per capita sales of alcohol and legal medical cannabis using fixed effect panel data linear regressions. The data covered seven Canadian regions from January 2011 to September 2018, and controlled for changing levels of retail activity, alcohol prices, tertiary education, unemployment, and impaired driving penalties. The analysis estimated that each dollar of legal medical cannabis sold was associated with an average alcohol sales decrease of roughly $0.74 to $0.84. This suggests that medical cannabis was an economic substitute for alcohol in Canada, and that the country's 2017-2018 alcohol sales were roughly 1.8% lower than they would have been without legal medical cannabis. The results therefore indirectly imply that reduced alcohol consumption might have partly offset cannabis legalization's health and economic impacts.

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

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

Alcohol Use Motives and Cannabis Use among Young Adults: Between- and Within-Person Associations Based on Monthly Data from a Community Sample

Objective: Alcohol use motives may characterize types of drinking that have unique associations with cannabis use and illuminate psychological processes underlying cannabis use. This study examined how alcohol use motives, both on average across two years and in a particular month, were associated with any and frequent cannabis use. Method: A young adult community sample (n = 486; 54% female, age 18-23 at enrollment) who used alcohol and cannabis in the year prior to study enrollment provided two years of monthly data. Multilevel logistic regression models predicting any and frequent (10+ occasions) past-month cannabis use estimated both between- and within-person effects of alcohol use motives, controlling for frequency of alcohol use and demographic covariates. Results: Alcohol use frequency was positively associated with any cannabis use at the between- and within-person levels and frequent cannabis use at the within-person level. Across two years, individuals who had higher average coping drinking motives and lower average social and conformity drinking motives were more likely to use cannabis frequently. Further, between-person variation in social motives was negatively associated with any cannabis use. Within-person, months with greater enhancement and social motives were associated with higher probability of any cannabis use. Conclusions: Using alcohol for coping reasons, rather than other-focused social reasons, indicated greater risk for frequent cannabis use, although drinking for social and enhancement reasons in a particular month signaled slightly increased short-term probability of any cannabis use. Assessment of alcohol motives may help guide targeting and timing of prevention related to cannabis use.

Do alcohol and cannabis substitute or complement each other? Analysis from behavioral economics for formulating public policy on substance use in Colombia

After alcohol and tobacco, cannabis is the third most used substance among young Colombian adults, and many consume alcohol and cannabis concomitantly. However, academics have debated whether these substances substitute or complement each other among consumers. Understanding the relationship between the price and demand for psychoactive substances can clarify consumption patterns and help to develop strategies to reduce harmful consumption. This paper summarizes worldwide evidence of both complementary and substitution relationships and discusses the most probable relationship types in Colombia based on its substance use patterns and current regulations. Like other countries, Colombia is considering legalizing recreational cannabis use. However, there is a growing concern that legalization would increase the negative impacts of cannabis and increase alcohol use among the young adult population. The lack of Colombian empirical studies about the impacts of legal changes on the cannabis market makes it difficult to predict how such changes would affect demand and price elasticities.

Cannabis Use, Use Motives and Cannabis Use Disorder Among Berlin College Students

This study described cannabis use behavior among college students in Berlin, in particular, differences in use motives between subjects with frequent use and those with signs of cannabis use disorder (CUD). Cross-sectional data were collected via an online survey among Berlin college students ( N=9350; 50.7% women; Mage=24.4). Motivation scales were computed based on an exploratory factor analysis. Effects of these motive scales were compared using multivariate regression models, where the dependent variable was use intensity (ordinal), frequent use (twice or more per week, binary) or a positive substance use disorder screening test (binary). Cannabis use is known to be particularly prevalent among Berlin college students, which was confirmed by our data. The most frequent use motive was enhancement, which, however, was not associated with frequent use or CUD. The motives predicting frequent use (sociability) are different from motives predicting CUD (coping), even when controlling for a wide array of covariates.

Relationships of Cannabis Policy Liberalization With Alcohol Use and Co-Use With Cannabis: A Narrative Review

PURPOSE

The liberalization of cannabis policies has the potential to affect the use of other substances and the harms from using them, particularly alcohol. Although a previous review of this literature found conflicting results regarding the relationship between cannabis policy and alcohol-related outcomes, cannabis policies have continued to evolve rapidly in the years since that review.

SEARCH METHODS

The authors conducted a narrative review of studies published between January 1, 2015, and December 31, 2020, that assessed the effects of cannabis policies on the use of alcohol in the United States or Canada.

SEARCH RESULTS

The initial search identified 3,446 unique monographs. Of these, 23 met all inclusion criteria and were included in the review, and five captured simultaneous or concurrent use of alcohol and cannabis.

DISCUSSION AND CONCLUSIONS

Associations between cannabis policy liberalization and alcohol use, alcohol-related outcomes, and the co-use of alcohol and cannabis were inconclusive, with studies finding positive associations, no associations, and negative associations. Although several studies found that cannabis policy liberalization was associated with decreases in alcohol use measures, these same studies showed no impact of the cannabis policy on cannabis use itself. The lack of a consistent association was robust to subject age, outcome measure (e.g., use, medical utilization, driving), and type of cannabis policy; however, this may be due to the small number of studies for each type of outcome. This paper discusses several notable limitations of the evidence base and offers suggestions for improving consistency and comparability of research going forward, including a stronger classification of cannabis policy, inclusion of measures of the alcohol policy environment, verification of the impact of cannabis policy on cannabis use, and consideration of mediation effects.

Physical Harm Reduction in Domestic Violence: Does Marijuana Make Assaults Safer?

Studies on the effect of marijuana on domestic violence often suffer from endogeneity issues. To examine the effect of marijuana decriminalization and medical marijuana legalization on serious domestic assaults, we conducted a difference-in-differences analysis on a panel dataset on NIBRS-reported assaults in 24 states over the 12 years between 2005 and 2016. Assaults disaggregated according to situation and extent of injury were employed as dependent variables. We found that while the total number of assaults did not change, decriminalization reduced domestic assaults involving serious injuries by 18%. From a harm reduction perspective, these results suggest that while the extensive margin of violence did not change, the intensive margin measured by the seriousness of assaults were substantially affected by decriminalization. This result may be partially explained by reductions in offender alcohol intoxication and weapon-involved assault.

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.

Medical Cannabis Laws and Adolescent Alcohol Use Initiation

Background

The effects of medical cannabis laws (MCLs) on adolescent alcohol use remains unclear. Previous literature investigates alcohol consumption rather than alcohol initiation among adolescents, and does not examine the effect by sociodemographic characteristics and state-level dispensary status. We used population representative, state-level data to examine the relationship between MCLs and adolescent alcohol initiation.

Methods

Data for this study were derived from the Youth Risk Behavior Survey (YRBS), a nationally representative, cross-sectional school-based survey administered by the Centers for Disease Control (CDC) in odd-numbered years from 1991 to 2015. We used a difference-in-difference model to assess pre and post effects of state MCL enactment on adolescent alcohol use initiation. Logistic regression analyses assessed associations between MCLs and varying ages of initiation. We further stratified our results by race/ethnicity, gender, and dispensary status.

Results

Results from adjusted logistic regression models showed higher odds of initiating alcohol among adolescents in states without MCLs when compared to adolescents in states with MCLs (OR 1.37, [95% CI = 1.29, 1.44]). This effect was consistent across age, race/ethnicity, and gender groups. Reductions in self-report of alcohol initiation were also consistently found in multiple age strata (9-10, 11-12, and 13-14), though this finding did not reach conventional levels of statistical detection in all race/ethnicities.

Conclusions

Our findings support a substitutive effect, suggesting that adolescents in states with MCLs, as opposed to states without MCLs, may substitute cannabis for alcohol. Considering the evolving landscape of medical cannabis laws and the proliferation of state-level legalization laws, further research into the effects of such policies, such as adult-use cannabis laws, is warranted to further elucidate their effects on adolescent substance 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.

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

A systematic review of addiction substitution in recovery: Clinical lore or empirically-based?

This systematic review synthesized the literature examining addiction substitution during recovery from substance use or behavioral addictions. A total of 96 studies were included with sample sizes ranging from 6 to 14,885. The most common recovery addictions were opioids (30.21%), followed by cannabis (20.83%), unspecified use (17.71%), nicotine (12.50%), alcohol (12.50%), cocaine (4.17%), and gambling (2.08%). Statistical results were provided by 70.83% of the studies. Of these, 17.65% found support for addiction substitution, whereas 52.94% found support for concurrent recovery. A total of 19.12% found no statistical changes and 10.29% found both significant increases and decreases. The remaining 29.17% of studies provided descriptive data, without statistical tests. Predictors of addiction substitution were provided by 22.92% of the studies and 11.46% included information on impact of addiction substitution on treatment outcomes. Overall, male gender, younger age, greater substance use severity, and presence of mental health disorders were associated with addiction substitution. Addiction substitution was associated with poorer treatment outcomes. A limitation of the present systematic review is the use of significance counting for the quantitative synthesis. More research examining changes in addiction during recovery would aid in the development of more effective treatments for addictive disorders and prevent addiction substitution.

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).

Dual trajectories of cannabis and alcohol use among young adults in a state with legal nonmedical cannabis

BACKGROUND

Understanding the nature of the association between cannabis and alcohol use within individuals over time in the era of legalized cannabis is of crucial importance for assessing the public health consequences of increasing cannabis use. An important unanswered question is whether cannabis and alcohol use substitute for one another. Specifically, is greater use of one substance associated with less use of the other substance (i.e., a negative association) or are the substances complementary and their association positive?

METHODS

We used 24 consecutive months of data on a young adult sample (n = 774; 56% female, age 18-25 during the study) who drank alcohol in the year prior to enrollment. The sample was recruited in Washington State in 2015/2016 (after legalization of nonmedical cannabis) using media advertisements and community flyers and outreach. Using parallel process latent growth curve models, we assessed three types of association between cannabis and alcohol use across the 24-month period: (1) an association between average levels of cannabis and alcohol use; (2) an association between rates of change in cannabis and alcohol use; and (3) correlations between shorter-term deviations/fluctuations off of longer-term trajectories of level and change in cannabis and alcohol use.

RESULTS

We found a positive association between the average frequency of cannabis and alcohol use; individuals who used cannabis more frequently on average also drank alcohol more frequently on average. Change over time in cannabis use was positively associated with change in alcohol use. There was also a contemporaneous positive association between fluctuations in cannabis and alcohol use.

CONCLUSIONS

Overall, we found no evidence of substitution. Rather, the results suggest a complementary relationship between cannabis and alcohol use, such that the use of cannabis and alcohol rises and falls together.

Patterns of same-day alcohol and cannabis use in adolescents and young adults with risky alcohol use

Same-day alcohol and cannabis use is relatively common in adolescents and young adults, constituting a higher-risk behavior relative to single-substance use. However, the association between quantity of alcohol and cannabis use on co-use days is understudied. We examined the association between the quantity of alcohol and same-day cannabis use with a multilevel regression analysis in a sample of youth (16-24 years old) with risky alcohol use. Participants reported one or more days of alcohol and cannabis over the past month (N = 468). Quantity of cannabis use was highest on heavy drinking days [M = 0.91 grams, SD = 0.68] followed by moderate drinking days (M = 0.78 grams, SD = 0.63), and lowest on days without alcohol use (M = 0.74 grams, SD = 0.64, p < 0.001). In multilevel modeling analyses, adjusted for clustering within individuals, greater quantity of drinking on a given day was associated with greater cannabis use (estimate = 0.03, p < 0.001). When using alcohol and cannabis on the same day, greater alcohol use was associated with greater cannabis use. Preventing days of heavy use of multiple substances, particularly among at-risk drinkers, may complement interventions addressing co-use generally to prevent substance-related consequences.

Prevalence of Substance Use in University Students, Ethiopia

BACKGROUND

Although substance use is a known public health problem and a pressing issue in Ethiopia, its real extent and magnitude are not yet properly explored. The current study aimed to determine the extent and predictors of substance use among regular undergraduate students in the Institute of Technology, Addis Ababa University.

METHODS

An institution-based cross-sectional study was carried among 794 undergraduate regular students at the Institute of Technology, Addis Ababa University, using a self-administered structured questionnaire filled by study participants. Data entry, cleaning, and coding were performed by EPI-INFO version 3.5.1. Statistical Package for Social Sciences; AOR: Adjusted odds ratio (SPSS) SPSS version 21 software was used to analyze data by performing descriptive statistics, bivariate, and multivariate analysis.

RESULTS

73.7% of the study participants used substances at least once. The lifetime use of each substance includes alcohol (68.2%), khat (53.6%), cigarettes (46.1%), and illicit drugs (23.3%). Loss of family (AOR [95%CI], 34.50 [7.569, 157.263]), pocket money between 500 and 999 Ethiopian birr (AOR [95%CI], 9.978 [1.240, 80.280]), and above 1000 Ethiopian birr (AOR [95%CI], 10.831 [1.333, 87.971]) were identified predictors for khat use. The odds of lifetime alcohol use was higher among students coming from a divorced family (AOR [95%CI], 9.346 [3.162, 27.625]), lost one (AOR [95%CI], 37.406 [11.375, 123.008]), or both of their parents (AOR [95%CI], 18.750 [5.798, 60.633]). Students of urban origin (AOR [95%CI], 3.214 [1.950, 5.296]), and students with anxiety symptoms (AOR [95%CI], 2.655 [1.981, 3.557]) have a higher odds of lifetime cigarette smoking. The lifetime exposure to illicit drugs is higher among students in age groups between 20 and 24 years (AOR [95%CI], 5.963 [1.361, 26.135]), students coming from substance user family (AOR [95%CI], 2.172 [1.161, 4.063]), and students of urban origin (AOR [95%CI], 2.661 [1.202, 5.889]).

CONCLUSION

A higher prevalence of substance use requiring administrative and educational interventions was observed. Awareness creation interventions on the potential impacts of substance abuse should be performed.

Ordering in alcohol and cannabis co-use: Impact on daily consumption and consequences

BACKGROUND

Co-use of alcohol and cannabis is highly prevalent among young adults and college students. Between-person reports suggest that co-use is associated with the experience of more frequent consumption and related consequences, compared to single substance use. However, recent studies have found conflicting evidence regarding the impact of co-use use on consumption and consequences in daily or event-level investigations. Conflicting evidence may be due to understudied factors, such as the order in which alcohol and cannabis are used. The current study aimed to examine the effect of substance use order on a) alcohol consumption; b) cannabis consumption; and c) negative alcohol and cannabis consequences.

METHODS

Data were collected from U.S. undergraduate college student alcohol and cannabis users (N = 258) who completed two 28-day longitudinal online assessment bursts examining alcohol and cannabis co-use patterns. Data were collected five times per day during both bursts (three months apart).

RESULTS

Controlling for between-person alcohol and cannabis use, within-person mixed-effects models indicated that using cannabis first within a co-use day was associated with lower daily alcohol consumption, but greater daily cannabis consumption. Substance use ordering was not linked to consequences, whereas between-person levels of alcohol consumption and within-person number of drinks in a day were positive predictors of consequences.

CONCLUSIONS

Overall, results highlighted that order of substance use is a robust predictor of consumption on co-use days. Therefore, future research on co-use use should consider patterns of use in addition to level of use.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Multifaceted impulsivity as a moderator of social anxiety and cannabis use during pregaming

Individuals may drink or use cannabis to cope with social anxiety, and drinking or using cannabis prior to social situations (e.g., pregaming) may be a way to limit the experience of anxiety when entering social settings. However, theoretical and empirical work has reported mixed associations between social anxiety and substance use, specifically alcohol and cannabis. Little work has looked at how other variables, such as impulsivity (a central component to high risk drinking such as pregaming), may shed light onto these mixed findings. College students who reported past year pregaming (n = 363) completed self-report surveys. Supporting prior work, we found that social anxiety was associated with fewer pregaming days, even among those high in sensation seeking. However, those reporting higher social anxiety also reported higher cannabis use during pregaming, specifically among those who reported high sensation seeking and high positive urgency. Results suggest specific facets of impulsivity may affect the association between social anxiety and cannabis use during high risk drinking events.

Cannabis and Alcohol Co-Use in a Smoking Cessation Pharmacotherapy Trial for Adolescents and Emerging Adults

INTRODUCTION

The co-use of cannabis and alcohol among tobacco-using youth is common. Alcohol co-use is associated with worse tobacco cessation outcomes, but results are mixed regarding the impact of cannabis on tobacco outcomes and if co-use leads to increased use of non-treated substances. This secondary analysis from a youth smoking cessation trial aimed to (1) evaluate the impact of cannabis or alcohol co-use on smoking cessation, (2) examine changes in co-use during the trial, and (3) explore secondary effects of varenicline on co-use.

METHODS

The parent study was a 12-week, randomized clinical trial of varenicline for smoking cessation among youth (ages 14-21, N = 157; Mage = 19, 40% female; 76% White). Daily cigarette, cannabis, and alcohol use data were collected via daily diaries during treatment and Timeline Follow-back for 14 weeks post-treatment.

RESULTS

Baseline cannabis co-users (68%) had double the odds of continued cigarette smoking throughout the trial compared with noncannabis users, which was pronounced in males and frequent cannabis users. Continued smoking during treatment was associated with higher probability of concurrent cannabis use. Baseline alcohol co-users (80%) did not have worse smoking outcomes compared with nonalcohol users, but continued smoking was associated with higher probability of concurrent drinking. Varenicline did not affect co-use.

CONCLUSIONS

Inconsistent with prior literature, results showed that alcohol co-users did not differ in smoking cessation, whereas cannabis co-users had poorer cessation outcomes. Youth tobacco treatment would benefit from added focus on substance co-use, particularly cannabis, but may need to be tailored appropriately to promote cessation.

IMPLICATIONS

Among youth cigarette smokers enrolled in a pharmacotherapy evaluation clinical trial, alcohol and/or cannabis co-use was prevalent. The co-use of cannabis affected smoking cessation outcomes, but more so for males and frequent cannabis users, whereas alcohol co-use did not affect smoking cessation. Reductions in smoking were accompanied by concurrent reductions in alcohol or cannabis use. Substance co-use does not appear to affect all youth smokers in the same manner and treatment strategies may need to be tailored appropriately for those with lower odds of smoking cessation.

Motives for Alcohol and Marijuana Use as Predictors of Use and Problem Use Among Young Adult College Students

This study examined (a) differences between alcohol-only users and alcohol-marijuana co-users and (b) motives for use in relation to alcohol and marijuana use and problem use. Spring 2016 data among 1,870 past 4-month alcohol users (63.6% female, 69.1% White) from seven Georgia colleges/universities were analyzed cross-sectionally and with regard to problem use measured 4 months later. Correlates of co-use (n = 345; vs. alcohol-only use, n = 1,525) included greater alcohol and marijuana use frequency, problem drinking and marijuana use, and alcohol use motives (p's < .05). Controlling for covariates, alcohol use frequency correlated with greater marijuana use frequency and Coping and Self-enhancement alcohol use motives, but lower Conformity alcohol use motives (p's < .001); greater Coping and Self-enhancement alcohol use motives (p's < .01) predicted problem alcohol use. Marijuana use frequency correlated with greater Coping and Expansion marijuana use motives (p's < .05); greater Expansion marijuana use motives (p = .005) predicted problem marijuana use. College-based substance use interventions should target Coping and Self-enhancement alcohol use motives and Expansion marijuana use motives.

Does cannabis complement or substitute alcohol consumption? A systematic review of human and animal studies

BACKGROUND

Whether alcohol and cannabis complement or substitute each other has been studied for over two decades. In the changing cannabis policy landscape, debates are moving rapidly and spill-over effects on other substances are of interest.

AIMS

update and extend a previous systematic review, by: (a) identifying new human behavioural studies reporting on substitution and/or complementarity of alcohol and cannabis, and (b) additionally including animal studies.

METHODS

We replicated the search strategy of an earlier systematic review, supplemented with a new search for animal studies. Search results were crossed checked against the earlier review and reference lists were hand searched. Findings were synthesised using a narrative synthesis.

RESULTS

Sixty-five articles were included (64 in humans, one in animals). We synthesised findings into categories: patterns of use, substitution practices, economic relationship, substance use disorders, policy evaluation, others and animal studies. Overall, 30 studies found evidence for substitution, 17 for complementarity, 14 did not find evidence for either, and four found evidence for both.

CONCLUSIONS

Overall, the evidence regarding complementarity and substitution of cannabis and alcohol is mixed. We identified stronger support for substitution than complementarity, though evidence indicates different effects in different populations and to some extent across different study designs. The quality of studies varied and few were designed specifically to address this question. Dedicated high-quality research is warranted.

Characteristics associated with marijuana use in Latinx college students

While marijuana use rates are significantly high within college students, less is known about use patterns and correlates in Latinx groups. This study assessed the relationships between ever use and frequency of use of marijuana, polysubstance use, expectancies, motives, and mental illness symptoms among Latinx college students (n = 345). Results indicated more frequent marijuana use was positively associated with: enjoyment, celebration, social anxiety, low risk, sleep and availability and was negatively associated with: experimentation, boredom, altered perception, and anxiety. Other dual use with tobacco expectancies were also observed. These constructs should be explored prospectively and inform prevention and intervention efforts.

Does use of other tobacco products change when cigarette smoking status changes: A descriptive study of young adults

BACKGROUND

Whether polytobacco use or nicotine dependence (ND) change when cigarette smoking status changes in young adults is an understudied issue. Our objective was to describe use of other tobacco products (OTPs) and ND according to change in cigarette smoking status over four years in young adults.

METHODS

We drew data from a longitudinal study of 1294 adolescents age 12-13 at inception in 1999-2000 and followed into young adulthood. Among 790 participants with data at age 20 and 24, 22% had never smoked cigarettes; 37% were "sustained smokers"; 9% were "relapsers"; 10% had quit 1-3 years ago; and 22% had quit ≥4 years ago. We described past-year OTP (i.e., cigars/cigarillos, waterpipe, sundry tobacco products (i.e., pipe, bidis, chewing tobacco, snuff)) use and ND over 4 years in these groups.

RESULTS

At age 20, sustained smokers reported using a mean(SD) of 1.1(0.9) OTP in the past-year; relapsers reported 0.5(0.6); shorter-term quitters reported 0.9(0.7); longer-term quitters reported 0.3(0.6); and never smokers reported 0.2(0.4). There was no change in OTP use or ND in never smokers and longer-term quitters. Shorter-term quitters reduced the number of OTPs by -0.5(95% confidence interval: -0.7,-0.3) on average over 4 years; sustained smokers decreased by -0.2(-0.3,-0.1). Relapsers increased by 0.6(0.4,0.7) on average.

CONCLUSIONS

OTP use and ND were stable in early adulthood among never smokers, sustained smokers and longer-term quitters, but fluctuated in parallel with stopping and starting to smoke. Research is needed to ascertain the underpinnings of these fluctuations and whether they help or hinder cessation.

Changes in alcohol and cigarette consumption in response to medical and recreational cannabis legalization: Evidence from U.S. state tax receipt data

BACKGROUND

Whether medical or recreational cannabis legalization impacts alcohol or cigarette consumption is a key question as cannabis policy evolves, given the adverse health effects of these substances. Relatively little research has examined this question. The objective of this study was to examine whether medical or recreational cannabis legalization was associated with any change in state-level per capita alcohol or cigarette consumption.

METHODS

Dependent variables included per capita consumption of alcohol and cigarettes from all 50 U.S. states, estimated from state tax receipts and maintained by the Centers for Disease Control and National Institute for Alcohol Abuse and Alcoholism, respectively. Independent variables included indicators for medical and recreational legalization policies. Three different types of indicators were separately used to model medical cannabis policies. Indicators for the primary model were based on the presence of active medical cannabis dispensaries. Secondary models used indicators based on either the presence of a more liberal medical cannabis policy ("non-medicalized") or the presence of any medical cannabis policy. Difference-in-difference regression models were applied to estimate associations for each type of policy.

RESULTS

Primary models found no statistically significant associations between medical or recreational cannabis legalization policies and either alcohol or cigarette sales per capita. In a secondary model, both medical and recreational policies were associated with significantly decreased per capita cigarette sales compared to states with no medical cannabis policy. However, post hoc analyses demonstrated that these reductions were apparent at least two years prior to policy adoption, indicating that they likely result from other time-varying characteristics of legalization states, rather than cannabis policy.

CONCLUSION

We found no evidence of a causal association between medical or recreational cannabis legalization and changes in either alcohol or cigarette sales per capita.

The Relationship between Negative Affect and Alcohol and Marijuana Use Outcomes among Dual Users

Background: Past research with college students has found that substance use motives, particularly coping motives, mediate the relationship between negative affect and alcohol- and marijuana-related outcomes. Objectives: This study aimed to investigate substance use motives of dual users of both substances (past 30-day use; not necessarily simultaneous use) and identify any mediation effects that are either common to both substances or substance-specific. Methods: The majority of dual users (n = 2,034) identified as being White, non-Hispanic (63.8%), female (69.08%), and reported a mean age of 20.24 (SD = 3.16) years. To test study aims, path models were conducted such that negative affect (stress, depressive and anxiety symptoms) were independently modeled as predictors of substance use outcomes (i.e. quantity and consequences) via substance use motives. Results: All three negative affect symptoms were indirectly related to both alcohol and marijuana consequences via coping motives, such that higher negative affect was associated with higher coping motives; which in turn were positively associated with consequences. Substance-specific effects were also found: (a) stress was indirectly related to both alcohol and marijuana use quantity via enhancement motives, (b) depressive/anxiety symptoms were indirectly related to alcohol use quantity via enhancement motives, and (c) all three negative affect symptoms were indirectly related to both marijuana use quantity and negative consequences via expansion motives. Conclusions: Findings suggests that dual users of alcohol and marijuana with negative affect symptoms engage in substance use for similar reasons as single substance users with negative affect symptoms. Intervention efforts should examine ways to replace substance-related coping and expansion methods with non-substance-related methods.

A longitudinal examination of daily patterns of cannabis and alcohol co-use among medicinal and recreational veteran cannabis users

BACKGROUND

Prompted by the ongoing debate regarding whether cannabis serves as a complement to or substitute for alcohol, this study uses prospective data to examine daily associations between medicinal versus recreational cannabis and alcohol use in veterans.

METHODS

Three semi-annual waves of Timeline Followback Interview data were collected from a sample of veterans who reported co-using alcohol and cannabis on at least one day (N = 115; 56% medicinal users; 93% male; 62,100 observations). Linear mixed effects models were used to examine the association between daily cannabis use and number of drinks consumed across time for both medicinal and recreational users and to examine the frequency medicinal cannabis used to substitute for alcohol.

RESULTS

Compared to medicinal users, recreational users were more likely to drink more on cannabis use days relative to non-use days. Among medicinal users, those endorsing more frequent use of cannabis as a substitute for alcohol reported fewer number of drinks consumed on days when cannabis was used relative to non-use days.

CONCLUSIONS

Among veterans, recreational users are at greater risk for increased drinking when co-using cannabis at the daily level, an association that is stable over time. Medicinal users may be at lower risk for increased drinking on days when cannabis is also used, especially those who endorse using cannabis to substitute for alcohol. Findings help clarify the debate on cannabis-alcohol substitution or complementary associations in a sample of veterans and suggests that alcohol interventions should address cannabis use as a risk factor, especially for recreational users.

Perceived Social Support from Significant Others among Binge Drinking and Polyconsuming Spanish University Students

Sense of acceptance is conceived as a central component of perceived social support and is thought to be a key resilience factor for adjustment during transition to university. The current study examines how a binge drinking pattern of alcohol consumption and the co-consumption of binge drinking and cannabis in first-year university students are related to perceived acceptance from family, mother, father, and friends. The study sample consisted of 268 women and 216 men, of average age 18.25 years (SE = 0.01), enrolled in the first year of different degree courses at the University of Santiago de Compostela. Participants were classified in three groups (control, binge drinking, polyconsuming) on the basis of the Timeline Followback for alcohol and cannabis. Perceived sense of acceptance was measured using the Perceived Acceptance Scale. Analysis of the data revealed that perceived acceptance was lower in polyconsuming students than in the binge drinking and control groups (p < 0.05; with η2 ranging between 0.009 and 0.020). A curvilinear relationship between binge drinking and perceived acceptance from friends was identified. Social support should be considered in future investigations and interventions as a vulnerability marker for detrimental consequences of substance use and risk of consumption disorders, as well as adolescent maladjustment.

Ambulatory Assessment of Adolescent Coping: It's a Complicated Process

Scholars have long-called for researchers to treat coping as a process that is measured over an arc of time. Ambulatory assessment (AA) offers an appealing tool for capturing the dynamic process of adolescent coping. However, challenges in capturing the coping process are not altogether circumvented with AA designs. We conducted a scoping review of the AA literature on adolescent coping and draw from 60 studies to provide an overview of the field. We provide critiques of different AA approaches and highlight benefits and costs associated with various types of measurement within AA. We also speak to considerations of participant burden and compliance. We conclude with recommendations for developmental scholars seeking to deploy AA to capture this quintessential process among adolescents.

Traffic fatalities within US states that have legalized recreational cannabis sales and their neighbours

BACKGROUND AND AIMS

A growing body of evidence suggests that cannabis impairs driving ability. We used mortality data to investigate whether the commercial sale of cannabis for recreational use affected traffic fatality rates both in states that legalized it and in neighbouring jurisdictions.

DESIGN

Interrupted time-series of traffic fatality rates adjusted for seasonality and autocorrelation. Changes are reported as step and trend effects against a comparator of states that had not implemented medicinal or recreational cannabis during the study period (2009-16). Sensitivity analyses added a 6-month 'phase-in' to account for lags in production. Meta-analyses were used to derive pooled results.

SETTING

Three states that legalized recreational cannabis sales [Colorado (January 2014), Washington State (June 2014) and Oregon (October 2015] and nine neighbouring jurisdictions [Kansas, Nebraska, New Mexico, Oklahoma and Utah (Colorado neighbours); British Columbia and Oregon (Washington neighbours); and California and Nevada (Oregon neighbours)].

MEASUREMENTS

Monthly traffic fatalities rates per million residents using mortality data from CDC WONDER and RoadSafetyBC and census data.

FINDINGS

There was a pooled step increase of 1.08 traffic fatalities per million residents followed by a trend reduction of -0.06 per month (both P < 0.001), although with significant heterogeneity between sites (step: I²  = 73.7%, P < 0.001; trend: I²  = 68.4%; P = 0.001). Effects were similar in both legalizing (step: 0.90, P < 0.001; trend: -0.05, P = 0.007) and neighbouring sites (step: 1.15, P = 0.005; trend: -0.06, P = 0.001). The 6-month phase-in produced similar if larger effects (step: 1.36, P = 0.006; trend: -0.07, P < 0.001).

CONCLUSIONS

The combination of step increases and trend reductions suggests that in the year following implementation of recreational cannabis sales, traffic fatalities temporarily increased by an average of one additional traffic fatality per million residents in both legalizing US states of Colorado, Washington and Oregon and in their neighbouring jurisdictions.

Is the Sum Greater than its Parts? Variations in Substance-Related Consequences by Conjoint Alcohol-Marijuana Use Patterns

Alcohol and marijuana are the most commonly used substances for college-attending young adults. This study evaluated differences in substance-specific consequence attribution by alcohol-marijuana use patterns (concurrent alcohol and marijuana [CAM; use of both substances, not at same time] and simultaneous [SAM; use of both, at same time]) as well as alcohol-only (AO). First-year college students with prior alcohol use (N = 610, 50.9% women, 71% White, M_age = 18) completed an online assessment of past-three-month substance use, including SAM, and related consequences. Results indicated that polydrug (SAM and CAM) users reported greater alcohol involvement and earlier alcohol initiation than AO, and polydrug use was associated with more alcohol-related problems, including sexual risk taking and alcohol-related blackouts. When restricted to SAM/CAM users, logistic regressions indicated that SAM users reported an increased incidence in two marijuana-related problems relative to CAM (driving after using and academic difficulties), but lower rates of social problems. SAM users were also less likely to attribute substance-related social problems to alcohol. Overall, findings highlight variations that exist within alcohol-marijuana polydrug users and show areas to consider for intervention development and future research.

Factors associated with cannabis use change in youth: Evidence from the COMPASS study

INTRODUCTION

Harmful effects of cannabis use in youth scale with frequency. In the context of approaching legalization in Canada, understanding the distinctions between youth who change and who maintain their cannabis use is essential for designing interventions and policy. A substantial number of characteristics may play a role. This study assessed whether and how youth who change their cannabis use differ from those who do not.

METHODS

Cannabis use was reported by 8375 Canadian high school students participating in the COMPASS study. GEE multiple logistic regressions were then used to establish impact of 13 baseline demographic and behavioural exposure variables on the likelihood of membership in four frequency change groups at follow-up a year later: reduction, cessation, escalation, and maintenance.

RESULTS

Groups were found to differ in several ways. Cessation group members (19.4% of users) were less likely to binge drink (OR 0.82), vape (OR 0.82), or attend class without completing homework (OR 0.72) than maintainers. Students who reduced their use (14.6% of users) were more likely to binge drink (OR 1.36), smoke (OR 1.20), and skip class (OR 1.21). Those who escalated (29.5% of users) were more likely to be male (OR 1.35) and to vape (OR 1.22).

CONCLUSIONS

Students who change their cannabis use differ in several demographic and behavioural characteristics. The results raise further concerns about the impact of e-cigarettes and the role of poly-substance use in high-risk trajectories. Distinct classes of cannabis users, essential for policy and intervention development, can be identified in high school populations.

Motives for and impairment associated with alcohol and marijuana use among college students

INTRODUCTION

Alcohol and marijuana use are prevalent on college campuses. As recreational marijuana use is legalized, more undergraduate students may use marijuana in combination with alcohol. The motives for, frequency of, and impairment associated with dual use (alcohol and marijuana) compared to alcohol-only use may differ. We examined motives for, frequency of, and impairment associated with alcohol use and dual use at a university in a state where recreational marijuana has been legalized.

METHOD

Undergraduate college students completed an anonymous online survey (N = 430) concerning alcohol and marijuana frequency, motives, and impairment. Students were classified as either alcohol-only users (n = 279) or dual users (n = 151).

RESULTS

Analyses indicated that among alcohol-only users, social motives predicted more alcohol use, while among dual users, enhancement motives predicted more alcohol and marijuana use and impairment. Coping motives predicted more marijuana use among dual users, but not more alcohol use. Frequency of alcohol and marijuana use predicted more impairment across both the alcohol-only and dual users.

CONCLUSIONS

Future research should examine the influence of marijuana use over time to understand how motives may change for previous alcohol-only users.

A longitudinal investigation of the association between cannabis use and alcohol use among people living with HIV

BACKGROUND

Both cannabis use and alcohol use are elevated among people living with HIV, but few studies have investigated the relationship between cannabis use and alcohol use in this population. This study examined the longitudinal association between cannabis use and alcohol use among people living with HIV and explored the moderating role of medicinal vs. recreational cannabis use.

METHOD

Participants were cannabis users (N=763) enrolled in the Ontario HIV Treatment Network Cohort Study (67% White, 88% male, 68% gay, median income in the $40,000-$50,000 range). Participants completed assessments of cannabis use, reasons for cannabis use, and alcohol use at baseline and at annual follow-ups (M = 3.42 completed assessments). Multilevel modeling was used to examine between-person and within-person associations between cannabis use and alcohol use over time.

RESULTS

Greater average frequency of cannabis use was associated with greater average alcohol consumption across participants. Participants classified as medicinal cannabis users reported more frequent cannabis use and less alcohol use on average than recreational cannabis users. Further, within-person changes in cannabis use over time were positively associated with corresponding changes in alcohol use for recreational cannabis users but not for medicinal users.

CONCLUSION

Cannabis use and alcohol use were positively associated over time among people living with HIV, although this association was specific to those using cannabis for recreational reasons. As alcohol use in this population poses significant health risks, more research on the link between cannabis use and alcohol use is needed, particularly in light of recent changes to cannabis regulations.

Marijuana use is associated with alcohol use and consequences across the first 2 years of college

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).

Daily Patterns of Marijuana and Alcohol Co-Use Among Individuals with Alcohol and Cannabis Use Disorders

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.

Are changes in drinking related to changes in cannabis use among Swedish adolescents? A time-series analysis for the period 1989-2016

AIMS

To examine if changes in alcohol consumption are associated with changes in cannabis use among Swedish adolescents in a period of diverging trends, and to investigate if cannabis and alcohol act as complements or substitutes.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

Data comprise a nationally representative annual school survey of alcohol and drug habits among Swedish 9th-grade students (aged 15-16 years) covering years 1989-2016 (n = 149 603). Alcohol and cannabis use were measured concurrently and alcohol consumption was measured in litres of 100% alcohol per year. Frequency of cannabis use was transformed into a mean using category mid-points. Autoregressive integrated moving average (ARIMA) time-series analysis was used to estimate the association between cannabis and alcohol use. To elucidate changes in the association during the study period, two subperiods (2000-16 and 1989-99) were analysed.

FINDINGS

There was a positive and statistically significant association between changes in alcohol consumption and changes in frequency of cannabis use among cannabis users for the period 1989-2016. A 1-litre increase in mean alcohol consumption was associated with a 0.28 increase in frequency of cannabis use (P = 0.010). The corresponding increase for the period 1989-99 was 0.52 (P = 0.003). When restricting the analysis to 2000-16, the association was not statistically significant (P = 0.735). When analysing all adolescents we found no statistically significant association between changes in alcohol consumption and changes in frequency of cannabis use.

CONCLUSIONS

From 1989 to 2016 there appears to be a positive association between alcohol and cannabis consumption among Swedish adolescents who use cannabis. This association seems to have become weaker over time, suggesting that alcohol and cannabis are neither substitutes nor complements among Swedish adolescents and that the recent decline in youth drinking is not associated with the increase in frequency of cannabis use.