one follow-up interview, 1324 had two follow-up interviews, 842 had three follow-up interviews, 428 had four follow-up interviews, and 8 had five follow-up interviews at the time of analysis. The analytic sample in the present study comprises all offspring who had complete EEG coherence data. Due to the majority European ancestral composition of the PGC AD GWAS, once COGA participants were removed, only individuals of European ancestry were included in this study (N = 1426 offspring from 913 European American nuclear families who had at least one follow-up interview, total number of observations = 5006). The number of observations available in the current study by age and sex are provided in Supplemental Figure S1. Among this analytic sample, the mean age at first interview was 17.1 (SD = 3.6, Range = 12–26), 51.6% were female, and self-reported ‘race’ was 98.1% European American, 0.1% African American, 0.1% Latin/Hispanic, and 4.4% ‘other’. 41% had a family history of AUD. Experimental protocols were approved by each site’s institutional review board, and informed consent was obtained from all participants. Parental permission was obtained for all participants under the age of 18.
