Heavy alcohol and cannabis use has been linked to poorer working memory, learning, and information processing which may affect academic performance among college students. Previous studies have demonstrated that those who use excessive amounts of alcohol and cannabis have lower GPAs compared to their sober peers. Other studies have shown that frequent cannabis users are more likely to drop out of college or have plans to delay their graduation compared to non-users. This study examines the relationship between alcohol and cannabis use and academic performance over four years of college.
The study’s sample consisted of 209 college students who completed a baseline assessment (Wave 1) and follow-up surveys one (Wave 2) and four (Wave 3) years after the baseline assessment. The surveys assessed frequency of alcohol and cannabis use during the past month, alcohol use disorder (AUD) and cannabis use disorder (CUD) symptoms, grades, and cumulative GPA. Data was analyzed using a random-intercept cross-lagged panel model to determine associations between substance use and academic performance.
Results of the data analysis showed that alcohol use frequency was significantly and negatively correlated to cumulative GPA at Waves 1 and 2. On the other hand, cannabis use frequency was significantly and negatively correlated to cumulative GPA at all three waves. CUD symptoms were also significantly and negatively associated with cumulative GPA at all three waves. At the between-person level CUD symptoms and grades were negatively correlated but AUD symptoms and grades were not significantly correlated. The between-level correlation between cannabis and alcohol frequency and grades was not significantly different than zero. At the within-person level, greater AUD symptoms in the first year of college was associated with decreased grades in the second year of college. There were no other statistically significant within-person associations identified.
Takeaway: Among college students, alcohol use disorder symptoms during the first year of college may help predict a within-person decline in grades during the second year of college.