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

Abstract

Cannabis is commonly used among people who drink alcohol, but findings are mixed regarding the direction of this relationship. The type of cannabis used [high-cannabidiol (CBD) vs. high-delta-9tetrahydrocannabinol (THC)] and motives for use (i.e., whether cannabis is used to treat a medical condition) may influence the relationship between cannabis and drinking. Specifically, CBD has shown preclinical promise in reducing alcohol consumption, and medical cannabis users report using cannabis to reduce drinking. This study leverages survey data from cannabis users who drink alcohol (N = 533). Respondents were categorized as using cannabis to treat (CTT) a medical condition or as individuals whose cannabis use is not intended to treat (NCTT) a medical condition and grouped based on the THC/CBD ratio of the flower or edible cannabis they typically use (e.g., “High-THC/CBD,” “Medium-THC/CBD” and “Low-THC/CBD”). The CTT group (n = 412) reported drinking significantly less frequently than the NCTT group (n = 121). Cannabinoid content of flower cannabis was associated with alcohol consumed on cannabis-use days, such that individuals in the High-THC/CBD group drink more on cannabis-use days compared to the Medium-THC/CBD group. Cannabinoid content of edible cannabis was associated with drinks per drinking occasion, such that the High-THC/CBD group consumed the most drinks and the Low-THC/CBD group consumed the fewest. For both edible and flower groupings, higher-THC/CBD cannabis was associated with more frequent co-use than lower-THC/CBD cannabis. Results suggest that whether someone uses cannabis to treat a medical condition may impact their drinking frequency, and the cannabinoid content in flower and edible cannabis impacts alcohol consumption.

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

“… 44 In another survey on co-use, those using cannabis to treat a medical condition reported drinking less often and having fewer drinks per drinking occasion compared to those who endorsed cannabis use for reasons other than a medical condition. 77 Finally, a large population-based study examined whether having a medical cannabis recommendation from a practitioner had any effect on alcohol consumption among participants who used both alcohol and cannabis. Those with a medical cannabis recommendation showed lower quantity and frequency of alcohol consumption and had lower scores (i.e., alcohol-related problems) on the Alcohol Use Disorders Identification Test (AUDIT) compared to cannabis users without a medical recommendation.…”

“…In one survey of persons who used cannabis and also drank alcohol, those who reported using products with a higher THC-to-CBD ratio also reported drinking less on drinking days. 77 In a second quasi-experimental study of persons who used cannabis and alcohol, those assigned to purchase and consume CBD products ad libitum, compared to THC or CBD+THC products, reported fewer drinking days and consumed fewer drinks on drinking days. 107 However, there were no differences on either outcome in the groups that were assigned THC compared to THC+CBD, suggesting that CBD does not attenuate the effects of THC on drinking frequency or quantity.…”

“…Those categorized as using high-THC products reported drinking more on cannabis use days relative to those who used low-THC products. 77 The significant variability in cannabinoid content and potency in cannabis products, paired with this preliminary evidence that cannabinoid content is associated with alcohol consumption, calls for more controlled research on the impact of various cannabinoids on alcohol use and alcohol-related outcomes (e.g., craving, consequences, high-intensity drinking).…”

Protocol for a mobile laboratory study of co-administration of cannabis concentrates with a standard alcohol dose in humans

“…Several individual-level variables may impact the alcohol-cannabis relationship, including understudied variables such as cannabinoid content (i.e., ratios of Δ9-tetrahydrocannabinol [THC] and cannabidiol [CBD]) [ 8 , 9 ] and the order in which alcohol and cannabis are consumed. Further complicating our understanding of the interplay between alcohol and cannabis is the fact that cannabis products containing high amounts of THC are increasingly popular within the legal, recreational cannabis market.…”