This document summarizes research on the effects of marijuana and alcohol on academic performance. It finds weak negative correlations between the frequency of marijuana and alcohol use and GPA. Students who use drugs and alcohol tend to skip more classes and have lower grades, especially in English and math. While marijuana was linked to increased extracurricular activities, both substances were associated with decreased initiative and increased classes skipped. Overall, alcohol appeared to have a more significant negative impact on academic metrics like averages, math marks, classes skipped, and initiative compared to marijuana.