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

Abstract

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.

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

“…For instance, the use of high-potency products, such as cannabis concentrates, was associated with more alcohol consequences on co-use days among college students who use both alcohol and cannabis. 114 This finding has been replicated in another study based on online surveys of respondents who reported co-use of alcohol and cannabis; respondents were categorized by high- versus low-THC product use. Those categorized as using high-THC products reported drinking more on cannabis use days relative to those who used low-THC products.…”

Changes in Alcohol Use and Drinking Context due to the COVID‐19 Pandemic: A Multimethod Study of College Student Drinkers

“…It is yet unknown whether the shift away from liquor will maintain once students return to campuses. If so, this may represent a positive change, given risks (e.g., blackouts) associated with rapidly rising blood alcohol concentrations that can occur upon taking “shots” (Labrie et al, 2011; Mochrie et al, 2019; Newman and Abramson, 1942) and as liquor, compared to beer or wine, consumption leads to experiencing more negative consequences (Stevens et al, 2020).…”

Early, Chronic, and Acute Cannabis Exposure and Their Relationship With Cognitive and Behavioral Harms

“…In another study, lifetime diagnosis of alcohol dependence has been found to increase the risk for lifetime cannabis dependence ( 43 ). On the other hand, although alcohol and marijuana/cannabis are frequently used simultaneously, studies suggest that acute negative consequences of co-use are associated with using more than one alcohol product ( 44 ).…”