Harmful drinking among colleges students in the United States is a widespread public health crisis that plagues university cultures with numerous consequences. As the research concerning alcohol consumption in college students continues to develop, associations with other forms of substance abuse also become more evident. Cannabis has been consumed at increasing rates in the United States, with young adult populations being at the forefront of this climb. This study aimed to test the interactions of alcohol and cannabis simultaneous co-use (“SAM”: simultaneous alcohol and marijuana use) with that of high intensity drinking (HID) and blackout frequency in college students, in addition to determining the presence of potential moderators in this interaction.
This study’s sample was composed of 1234 students from a university in the Midwestern United States (N=1234, 63.9% female, mean age = 18.42 yrs.). The participants responded to surveys which included measures related to their demographics, drinking quantity per occasion in the past year, frequency of HID (measured in intervals related to binge drinking thresholds, up to 3 times the standard 4-5/5-7 drink threshold for females/males), cannabis use frequency, SAM use frequency, and frequency of blackout experiences. The data was analyzed using binary logistic regressions and general linear modelling.
Results of the study found that 997 students reported using alcohol in the past year, and of those, 74.1% of males and 49.81% of females engaged in HID over twice the threshold for what is considered binge drinking. 38.82% of students who reported past-year alcohol consumption also reported a blackout experience. Cannabis use was reported by 55.3% of all participants, and SAM use was reported 67.1% of those who reported cannabis use. Blackouts occurred during past-year SAM use for 23.58% of SAM users. HID was directly associated with blackout frequency across genders, with SAM use resulting in an 82.1% increased probability of experiencing a blackout in the past year. SAM users who reported past year HID experienced overall more blackouts and increased blackout frequency rates than alcohol-cannabis co-users who used the respective substances in a non-simultaneous fashion (p<0.0001).
Takeaway: simultaneous use of alcohol and cannabis is related to negative consequences, with blackouts being a known example. High intensity drinking, at least in the past year, was found to serve as a moderator for SAM use and blackout frequency in college students. Interventions designed to treat students at-risk for alcohol/cannabis-related substance abuse may aim to focus on mitigating binge drinking episodes as well as education regarding alcohol and cannabis co-use.
Davis CN, Dash GF, Miller MB, Slutske WS. Past year high-intensity drinking moderates the association between simultaneous alcohol and marijuana use and blackout frequency among college students. Journal of American College Health. 2021;0(0):1-7. doi:10.1080/07448481.2021.1880415