Investigating Relationships Between Alcohol and Cannabis Use in an Online Survey of Cannabis Users: A Focus on Cannabinoid Content and Cannabis for Medical Purposes

Examining Associations Between Cannabis Use Disorder and Measures of Weekly and Within-Day Cannabis Frequency, Quantity, and Potency in College Students

Background: College student cannabis use has increased significantly in recent years, and individuals aged 18-25 are at elevated risk for development of cannabis use disorder (CUD). While weekly cannabis use frequency is a commonly used measure of cannabis consumption, there is increasing scientific interest in exploring more nuanced measures of cannabis use. Currently, limited research exists examining the clinical utility of cannabis quantity, within-day frequency, and potency variables. Methods: We used cross-sectional survey data from a sample of 617 undergraduate students in the state of Colorado. A two-part model-building approach was leveraged to examine whether within-session cannabis quantity and within-day cannabis use frequency were associated with odds of experiencing any CUD symptoms and total number of CUD symptoms endorsed. We also examined whether cannabis flower potency was associated with odds of experiencing any CUD symptoms and total number of CUD symptoms endorsed among a subset (N=288) of the sample who reported knowledge of the cannabinoid content of their most frequently used products. Results: Weekly flower use frequency (odds ratio [OR]=1.27, p<0.001) and weekly concentrate use frequency (OR=1.10, p=0.044) were positively associated with increased odds of experiencing any CUD symptoms, but cannabis quantity and within-day frequency variables were not. In addition, no association was found between flower potency and odds of endorsing any CUD symptoms. Among individuals endorsing at least one symptom, weekly flower use frequency (incident rate ratio [IRR]=1.06, p<0.001) was positively associated with total symptom count, but weekly concentrate use frequency, cannabis quantity variables, and within-day frequency variables were not. Among individuals endorsing symptoms, a positive association was found between flower potency and total symptom count (IRR=1.01, p=0.008). Conclusion: Current methods of assessing within-session cannabis quantity and within-day cannabis use frequency may lack clinical utility in examining college student CUD symptoms over and above weekly cannabis use frequency. Cannabis flower potency may prove useful in assessment of CUD symptom severity, but further research is warranted.

Probing the Paradox: Investigating the Impact of Affect, Exercise Type, and Cannabis Use on the Alcohol-Exercise Relationship in College Students

Alcohol has previously shown a paradoxical positive relationship with exercise behaviors. However, the relationship has not been explored according to type of exercise (aerobic vs. anaerobic), nor has the research considered other contextual variables that commonly co-occur with alcohol use, such as cannabis and mood. This study sought to expand upon previous research to understand how the alcohol-exercise relationship may vary based on exercise type. Additionally, this study included cannabis use and mood as moderators of the alcohol-exercise association. Cross-sectional survey data was collected from college students (N = 335). Negative binomial regression was used to test associations between exercise and alcohol consumption, cannabis use, positive affect (PA), negative affect (NA), and moderating effects of these factors on the alcohol-exercise relationship. Effect sizes are reported from an Incidence Rate Ratio (IRR). Sex assigned at birth (male = 1, female = 0; IRR = 1.34, p = .017), PA (IRR = 1.57, p = .001), and alcohol consumption (IRR = 1.94, p = .037) exhibited positive relationships with exercise. Significant main effects were not observed for negative affect (IRR = 1.17, p = .230), or cannabis use (IRR = 1.00, p = .988). There was a significant interaction between positive affect and alcohol consumption (IRR = 0.87, p = .044) predicting exercise minutes. Alcohol was positively associated with exercise for those with low positive affect (n = 42, b = 12.61, p = .096) and this effect was attenuated as levels of positive affect increased (mean positive affect: n = 232, b = 0.55, p = .926; high positive affect: n = 61, b = -15.86, p = .146). These findings suggest that low positive affect may contribute to the positive link between alcohol use and exercise (especially aerobic exercise) in young people.

Simultaneous Cannabis and Alcohol Use among Medical Cannabis Patients

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

Alcohol First, Cannabis Last: Identification of an Especially Risky Use Pattern among Individuals Who Co-Use Alcohol and Cannabis

Background: Alcohol and cannabis co-use is common and confers increased risk for potential harms, such as negative consequences and substance dependence. The existing evidence suggests that factors such as dose of delta-9-tetrahydrocannabinol (THC) consumed and order of use of each substance (i.e., using alcohol or cannabis first or last when co-using) may impact co-use outcomes. Existing co-use research has focused primarily on college-samples or young adults, and few studies have explored these nuanced relations among community samples. Methods: We examined survey data from 87 community members (mean age 32.9 years, 49.4% female) recruited from legal market cannabis dispensaries. Using a combination of regression techniques (i.e., OLS, negative binomial, censor-inflated) we modeled relations among co-use ordering patterns, THC dose and cannabis outcomes as well as interactions with sex assigned at birth and age. Results: Individuals who endorsed co-use reported significantly higher CUDIT scores than those who had never co-used (p < 0.01). Using alcohol first and cannabis last (a pattern we refer to as "AFCL") was more common among females than males (p < 0.01). In the context of typical substance use weeks, more frequently engaging in the AFCL pattern was associated with significantly higher CUDIT scores (p < 0.001) and negatively predicted positive consequences (p < 0.001). Other patterns predicted higher CUDIT scores during heavy use weeks. Conclusions: Results indicate that co-use ordering patterns are related to substance use outcomes. Further research leveraging within-subjects, longitudinal designs is needed to test causal relations between these variables.

Cannabis Use Patterns and Related Health Outcomes Among Spanish Speakers in the United States and Internationally

Cannabis and health research continue to largely ignore the usage patterns, perceptions, and medically related use in Spanish-speaking communities. The primary aim of this study was to collect data among Spanish-speaking communities on cannabis use that specifically characterizes granular demographic information, medically motivated and recreational use patterns including potency of products, medical motivations for use, and what perceptions are held as to risks and benefits. Secondarily, exploratory analyses were made to investigate potential effects of location or acculturation status. Five hundred forty-nine individuals completed the survey, including 294 residing in the United States (US) (M_age =31.8, SD=9.72; 154 women, 137 men, 3 non-binary and self-described individuals), 174 residing outside of the US (International) (M_age =26.6, SD=8.75; 77 women, 96 men, 1 non-binary and self-described individuals), and 81 who did not report country of residence (Unknown location) (M_age =26.7, SD=7.37; 17 women, 61 men, 3 non-binary and self-described individuals). Overall use was mostly recreational, while the US group was significantly more motivated by medical or combined medical and recreational reasons than the other two groups (p=0.02). The most common reason for medical use was anxiety or depression (14% of sample). The US group also smoked or vaporized significantly more often than the other two groups and was more likely to include daily users (p<0.001). The sample generally viewed the effects of cannabis use more favorably than negatively, but there were significant differences in these views between users and non-users. The rich heterogeneity suggested by these data belies the importance of taking an equity focused approach to cannabis research and will help to improve representation in the field.

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.