Nearly 60% of the sample had at least one parent with an AUD (39.1% one parent, 20.6% both parents), and an additional 4.7% had one parent with possible AUD. Rates of AUDs among fathers and mothers, respectively, were 41.8% and 33.0%. Among offspring with just one affected parent, AUD was more prevalent in fathers (64.6%) than mothers (35.4%). Table 1 contains demographics, rates of parental separation, and substance use variables for the sample as a whole and by parental AUD status (see Supplemental Table 2 for all covariates). In general, age at initiation of substance use and sexual debut were youngest among subjects with 2 AUD-affected parents, slightly older among subjects with 1 affected or possibly affected parent and oldest among subjects with no parental AUDs. This gradation by parental AUDs is apparent for alcohol initiation in Figure 1 (see Supplemental Figures 2–8 for other outcomes).
