A growing number of studies have documented unique risk from parental separation for early and problem drinking, controlling for parental history of alcoholism. The present study extends previous genetically informative research in this area by modeling genetic and environmental risk from parental alcohol and drug dependence history, with a time-varying measure of parental separation. Our focus on timing of alcohol transitions, including onset of first use, first alcohol dependence symptom, and alcohol dependence diagnosis, further extends previous studies by capturing the dynamic nature of drinking behavior, including possible shifts in the relative contribution of these risk factors across adolescence into young adulthood.
