During the screening session, participants completed a family tree of AUD for all primary and secondary biological relatives. If a subject identified a family member as having an AUD, follow-up questions consistent with FH-RDC for drinking consequences were included (Andreasen et al., 1977). Participants were enrolled regardless of FH status. Subjects were defined as FH+ if they reported at least one primary relative or two or more secondary relatives with history of AUD and as FH− if they reported at least two generations without AUD based on estimates of at least half of their secondary relatives. In cohorts 1 and 2, n = 81 (78%) and n = 83 (80%) subjects, respectively, could be identified as either FH+ or FH− (Table 1). Those who were not classified into FH groups reported one secondary relative with AUD, were unable to estimate at least half of secondary relatives, or were adopted.
