The Collaborative Study on the Genetics of Alcoholism (COGA) is an ongoing multi-site, family-based study designed to identify genes and traits associated with AUD (total N~17 762; Dick et al., 2023; Edenberg, 2002; Johnson et al., 2023; Reich et al., 1998). The COGA Prospective (COGA-P) Study (n = 3715) is a longitudinal sub-study of adolescent and young adult offspring with at least one parent who participated in the original COGA study and provided permission for offspring participation (Bucholz et al., 2017). All adult participants provided written informed consent, and minors verbal assent, to a protocol approved by each site’s institutional review board. Following quality control (Supplemental Methods), our final analytic sample included up to 15 463 observations from 3681 participants from 2186 nuclear families in 910 extended family pedigrees (51.3% female, 63.9% white, 27.4% Black, mean ± s.d. age at wave 1 = 16.02 ± 3.31 years; Table 1). Of these, 1935 and 918 are of European and African-American ancestry, respectively.
