Young adult use, dual use, and simultaneous use of alcohol and marijuana: An examination of differences across use status on marijuana use context, rates, and consequences.

Abstract

Objective: Co-use of alcohol and marijuana has increased among college students, though comparisons among simultaneous (i.e., use of both substances such that effects overlap), dual (i.e., use of both substances within a similar time period but without overlapping effects), and marijuana-only use are limited. This study aimed to understand differences between simultaneous, dual, and marijuana-only users on marijuana use rates, consequences, and context of use in a multi-university study. Method: College students (N = 4,764; M age = 19.9 years) who were mainly female (70.6%) and White (67.9%) completed an online survey. The Marijuana Use Grid captured marijuana use quantity/frequency, and the Brief Marijuana Consequences Questionnaire and the Cannabis Use Disorders Identification Test-Revised assessed problem use. Location, method of consumption, and social context of use also were assessed. Results: Fifty-five percent of the sample endorsed lifetime use of alcohol and marijuana. Of these students, 36.1% endorsed past-month simultaneous use, 10.8% endorsed past-month dual use, and 6.4% endorsed past-month marijuana-only use. Simultaneous users reported more marijuana use and problems than dual users. Marijuana-only users did not differ from simultaneous users on marijuana use indices, though they reported greater use than dual users as well. Simultaneous users used marijuana in plant form, at parties, and with unknown others a greater percentage of the time than dual users, while dual users used edibles and ingested marijuana a greater percentage of the time. Conclusions: Given their greater levels of marijuana use and marijuana-related problems, screening and interventions for simultaneous alcohol-marijuana use are needed in college students. Public Health Significance StatementWithin this study, college students who engaged in either marijuana-only or simultaneous use of alcohol and marijuana (i.e., use of both substances such that their effects overlapped) reported greater past 30-day marijuana use frequency, quantity, and consequences than those who engaged in dual use (i.e., use of both substances within a designated time period, but without effects overlapping). Based on the results of this study, more research is needed to understand etiological and contextual factors related to different use types.

Simultaneous Alcohol and Marijuana Use Among Young Adults: A Scoping Review of Prevalence, Patterns, Psychosocial Correlates, and Consequences

“… 23 , 28 , 55 , 56 , 60 , 67 In both college and community samples, individuals who engaged in SAM use reported a greater number of negative consequences relative to those who used alcohol only, 24 , 35 , 36 though findings were mixed when comparing individuals who engaged in SAM use with those who used concurrently. 24 , 36 , 38 Papers on SAM use frequency showed a similar pattern, with more frequent SAM use associated with greater negative consequences. 55 , 56 , 60 …”

“…Eight papers examined contexts associated with SAM use. 21 , 25 , 31 , 38 , 51 – 54 Overall, context was an important correlate associated with SAM use across samples (community, treatment seeking) and designs (cross-sectional, event-level). However, findings on specific settings were mixed.…”

“…Many papers found SAM use was greater among those who engage in heavier drinking and marijuana use. 16 , 20 – 24 , 28 , 31 – 38 For instance, one paper found that SAM use was most prevalent among those using four or more modes of cannabis administration (e.g., joint, bong, vape, edibles). 39 Another found that individuals who engaged in more frequent SAM use had a greater likelihood of any illicit drug use (not including marijuana).…”

“…This assessment typically involved pooling items from existing alcohol and/or marijuana consequence measures and modifying the instructions (e.g., “Below is a list of things that sometimes happen to people either during or after they have been drinking alcohol or using marijuana.” 24 ). Among most cross-sectional and longitudinal papers, 6 , 23 , 24 , 28 , 35 , 36 , 38 , 55 , 56 , 60 , 65 , 67 , 68 evidence consistently suggested a positive association between SAM use or same-day co-use and number of negative consequences experienced, even after controlling for demographics, impulsivity, delinquency, motives, alcohol use, and/or marijuana use. Of these papers, half focused on comparing individuals who engage in SAM use to individuals who use both substances concurrently or individuals who use alcohol only, 6 , 24 , 35 , 36 , 38 , 68 whereas the remaining focused on SAM use frequency as a predictor of consequences.…”

“…Among most cross-sectional and longitudinal papers, 6 , 23 , 24 , 28 , 35 , 36 , 38 , 55 , 56 , 60 , 65 , 67 , 68 evidence consistently suggested a positive association between SAM use or same-day co-use and number of negative consequences experienced, even after controlling for demographics, impulsivity, delinquency, motives, alcohol use, and/or marijuana use. Of these papers, half focused on comparing individuals who engage in SAM use to individuals who use both substances concurrently or individuals who use alcohol only, 6 , 24 , 35 , 36 , 38 , 68 whereas the remaining focused on SAM use frequency as a predictor of consequences. 23 , 28 , 55 , 56 , 60 , 67 In both college and community samples, individuals who engaged in SAM use reported a greater number of negative consequences relative to those who used alcohol only, 24 , 35 , 36 though findings were mixed when comparing individuals who engaged in SAM use with those who used concurrently.…”