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

Abstract

Aims Economists debate whether changes in availability of alcohol or cannabis are positively or negatively related to changes in use of the other substance. Implicit in these arguments are two competing, individual-level hypotheses—that people use alcohol and cannabis either as complements or substitutes for one another. This is the first study to test these hypotheses using micro-longitudinal data on individuals’ alcohol and cannabis use on a given evening. Methods United States college students who use alcohol and cannabis (n = 876) were selected from a larger sample who participated in a 30-day online daily diary study. At baseline, students reported their proclivity to use alcohol/drugs to cope with stress. Each day students reported their level of alcohol use from the prior evening as well as whether they had used cannabis. Results Evening levels of alcohol use and mean levels of alcohol use positively predicted the likelihood of evening cannabis use, results indicative of complementary use. This relation, however, was moderated by coping style, such that students who were more likely to use alcohol/drugs to cope were less likely to use cannabis as their evening or mean alcohol use levels increased, results indicative of substitution. Conclusions Substance-using college students showed evidence for complementary alcohol and cannabis use at both the within- and between-person levels. Students with a proclivity toward using alcohol/drugs to cope, however, showed evidence of substitution. These findings suggest that studies based on economic theories of substance use should take into account individual differences in substance use motives.

Is 4/20 an Event-Specific Marijuana Holiday? A Daily Diary Investigation of Marijuana Use and Consequences Among College Students

“…Moreover, given that a recent study found heterogeneity in types of marijuana users (Pearson et al, in press-b), future research is needed to examine how different types of marijuana users across various states celebrate 4/20, which would supply unique information as to who might be at risk for excessive consumption and/or consequences on 4/20. Additionally, given that alcohol use and marijuana use are complementary among college students (O'Hara et al, 2016), future research is needed to examine how polysubstance use may place students at elevated risks for negative consequences on 4/20.…”

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

“…Yet another possible explanation for the inconsistency regarding whether alcohol and cannabis act as substitutes or complements was presented by O'Hara et al . . Here, the authors concluded that complementary use was common among US college students, whereas substitution was more likely among those using alcohol and/or cannabis to cope with stress .…”

“…. Here, the authors concluded that complementary use was common among US college students, whereas substitution was more likely among those using alcohol and/or cannabis to cope with stress . This suggests that the question of substitution or complementarity is not only a matter of settings but can also vary between subgroups in a given setting, depending on the motives for using different substances.…”

Daily Marijuana Use is Associated with Missed Clinic Appointments Among HIV-Infected Persons Engaged in HIV Care

“…Future research on retention outcomes should measure marijuana use that is independent of whether or not a clinic or study visit is attended. This could be done using techniques such as ecologic momentary assessment or daily diaries (48–51). Finally, consistent with other retention studies, cancelled visits were not considered missed visits and were ignored in the analysis.…”