The impact of alcohol and marijuana use on academic achievement among college students

The present study explored the direct and indirect relationship between substance use, specifically alcohol and marijuana use, and academic achievement among college students, using skipping class as a mediator. Online self-administered surveys were distributed to undergraduate students at a mid-size university in the southeast. Individually, both alcohol and marijuana use significantly predicted GPA; as the frequency of students’ reported alcohol and marijuana use increased, GPAs decreased. However, when included in the same model, marijuana use appeared to mediate the relationship between alcohol use and GPA. Additionally, it was found that skipping class partially mediated the relationship between both alcohol use and GPA and marijuana use and GPA. Given the negative relationship that was found between substance use and academic achievement for all students in our sample, we highlight the importance of substance use prevention efforts that target students throughout the entirety of their college careers. We also discuss the limitations of current prevention efforts across college campuses that focus on alcohol use alone. We recommend that prevention efforts include a focus on marijuana use, in addition to alcohol use, especially given our current findings for marijuana use.