The S4S study recruited incoming students (n=15,067) at a large, urban, public university in the mid-Atlantic US, starting in 2011. All first-time freshmen aged >18 years were eligible to complete an online self-report survey, with follow-up surveys each subsequent spring in which they were enrolled at the university. Data collection was carried out using the secure REDCap system of electronic data capture tools (31). All participants provided informed consent, and the study was approved by the corresponding university Institutional Review Board. Full details on data collection have been previously published (37). The current study includes data from n=4,549 EUR participants from the first 5 cohorts whose DNA has been genotyped and passed quality control procedures.
