Department of Psychology, Virginia Commonwealth University, Richmond, Virginia.
Virginia Institute for Psychiatric and Behavioral Genetics, Richmond, Virginia.
Alcohol Clin Exp Res. 2019 Jun;43(6):1254-1262. doi: 10.1111/acer.14037. Epub 2019 Apr 29.
Peer drinking is one of the most robust predictors of college students' alcohol use and can moderate students' genetic risk for alcohol use. Peer effect research generally suffers from 2 problems: selection into peer groups and relying more on perceptions of peer alcohol use than peers' self-report. The goal of the present study was to overcome those limitations by capitalizing on a genetically informed sample of randomly assigned college roommates to examine multiple dimensions of peer influence and the interplay between peer effects and genetic predisposition on alcohol use, in the form of polygenic scores.
We used a subsample (n = 755) of participants from a university-wide, longitudinal study at a large, diverse, urban university. Participants reported their own alcohol use during fall and spring and their perceptions of college peers' alcohol use in spring. We matched individuals into their rooms and residence halls to create a composite score of peer-reported alcohol use for each of those levels. We examined multiple dimensions of peer influence and whether peer influence moderated genetic predisposition to predict college students' alcohol use using multilevel models to account for clustering at the room and residence hall level.
We found that polygenic scores (β = 0.12), perceptions of peer drinking (β = 0.37), and roommates' self-reported drinking (β = 0.10) predicted alcohol use (all ps < 0.001), while average alcohol use across residence hall did not (β = -0.01, p = 0.86). We found no evidence for interactions between peer influence and genome-wide polygenic scores for alcohol use.
Our findings underscore the importance of genetic predisposition on individual alcohol use and support the potentially causal nature of the association between peer influence and alcohol use.
同伴饮酒是预测大学生饮酒行为最有力的指标之一，并且可以调节学生饮酒的遗传风险。同伴效应研究通常存在两个问题：一是同伴群体的选择，二是更多地依赖于同伴饮酒的感知，而不是同伴的自我报告。本研究的目的是通过利用基于遗传的随机分配的大学室友样本，来检验同伴影响的多个维度以及同伴效应与遗传倾向对饮酒行为的相互作用（表现为多基因评分），从而克服这些局限性。
我们使用了一项大型、多样化、城市型大学的大学范围内纵向研究的子样本（n=755）。参与者在秋季和春季报告自己的饮酒情况，并在春季报告他们对大学同伴饮酒的看法。我们将个人匹配到他们的房间和宿舍，以创建每个水平的同伴报告的饮酒的综合得分。我们使用多层次模型来检验同伴影响的多个维度，以及同伴影响是否调节遗传倾向来预测大学生的饮酒行为，以考虑房间和宿舍水平的聚类。
我们发现多基因评分（β=0.12）、同伴饮酒的感知（β=0.37）和室友自我报告的饮酒量（β=0.10）均预测了饮酒行为（所有 p 值均<0.001），而整个宿舍的平均饮酒量（β=-0.01，p=0.86）则没有。我们没有发现同伴影响和全基因组多基因评分与饮酒之间存在交互作用的证据。
我们的研究结果强调了遗传倾向对个体饮酒行为的重要性，并支持了同伴影响与饮酒之间的关联具有潜在因果关系。
