High-risk alcohol use behavior and daily academic effort among college students.

It is not well understood whether heavy drinking interferes with academics on specific days or if this relationship simply reflects between-student differences.  = 736 college students completed 14 consecutive daily assessments during 7 semesters. Days were classified as non-drinking, moderate drinking, heavy episodic drinking only (HED-only), or high-intensity drinking (HID) days. Multilevel models tested associations between drinking level and academic behaviors. Students were more likely to skip class after engaging in HED-only or HID the previous day. On weekdays, students spent more time on schoolwork when they did not drink the previous day and spent less time on schoolwork when they engaged in HED-only and HID the previous day. On weekends, students spent less time on schoolwork after HED-only days. Heavy drinking is associated with lower academic effort the next day, highlighting the need for college programs targeting heavy alcohol use prevention and daily decision making.