Background: Excessive drinking is pervasive on college campuses. Yet, no studies have investigated whether college students’ heavy drinking affect their peers’ experiences of alcohol-related harms to others (AHTOs) and related consequences. People with and without heavy drinkers in their lives often differ systematically (e.g., by sex, race/ethnicity, or own drinking patterns), complicating such analyses. This study uses propensity score weighting to overcome this challenge while assessing the role of college students’ relationships with heavy drinkers in harms and related consequences.

Methods: Data are from a nationally representative survey of college students (n=1,945). Double-robust propensity score weighted logistic regressions estimated effects of respondents’ relationships with heavy drinkers on two sets of outcomes: 1) AHTOs (i.e., harassment, physical, sexual) and 2) Consequences (i.e., mental distress, service use due to someone else’s drinking). Secondary models stratified by the heavy drinker’s relationship to the participant (i.e., intimate peer, other peer, family member). All regressions applied a Bonferroni correction.

Results: In 2021, 1.6 million college students had a heavy drinker in their life. Students with heavy drinkers in their lives (vs. not) had higher odds of harassment (aOR=3.98 [2.16, 7.32]), physical (aOR=2.46 [1.11, 5.44]), and sexual AHTOS (aOR=2.92 [1.27, 6.75]). All relationship types were associated with harassment AHTO, but only heavy drinking intimate peers were associated with physical and sexual AHTO. Students with heavy drinkers in their lives (vs. not) had greater odds of frequent mental distress (aOR=2.05 [1.30, 3.23]) and service use (aOR=8.01 [3.74, 17.15]). All relationship types were associated with service use.

Conclusions: Relationships with heavy drinkers are a risk factor for college AHTO and consequences, particularly service use. Evidence-based strategies that decrease heavy drinking on college campuses and engage parents in student selection of friends, partners, and roommates may reduce the negative impact of these relationships.