In research on children of alcoholics, there are a growing number of studies that model jointly risk from parental separation and parental alcoholism (e.g., Dube et al., 2002; Thompson et al., 2008, 2013; Waldron et al., 2014b). This includes a handful of genetically informative Offspring-of-Twins (OOT) analyses (Gottesman & Bertelsen, 1989; Heath et al., 1985; Nance & Corey, 1976), where genetic and environmental risks to offspring are inferred from twin-parent and co-twin histories of alcoholism. For example, following from earlier analyses of adolescent and young adult offspring of male twins (Jacob et al., 2003), Sartor and colleagues (2007) examined onset of alcohol use and time to alcohol dependence from first use using a survival-analytic framework. Parental divorce uniquely predicted earlier initiation of alcohol use, with no significant effect of parental separation on timing of transition from first use to alcohol dependence. However, neither study modeled parental divorce as time-varying, instead assuming parental separation to predate offspring alcohol involvement.
