For this cross sectional, secondary analysis, data used in this study were derived from the first wave of the Missouri Family Study (MOFAM), an ongoing prospective community-based family study in which the main objective is to examine familial influences (paternal alcoholism) on adolescent offspring outcomes, including alcohol, tobacco, and illicit drug use, in a sample of ethnically diverse families (Edens, Glowinski, Pergadia, Lessov-Schlaggar, & Bucholz). Families were selected using birth record data from the state; this strategy has been described in detail for ascertainment of families of twins (Heath et al., 2002), and has been applied in the present study. Index children were chosen from birth years to be aged 13, 15, 17 or 19 at their baseline interview, and families with two or more full siblings were oversampled.
