To check the robustness of the results, we ran two series of sensitivity analyses. First, we fit the same model with parental history of alcohol dependence (PHAD), in place of the PRS, to represent latent genetic risk for alcohol use problems (Kendler et al., 2015). A PHAD variable was created from parents’ alcohol dependence (AD) diagnosis based on the fourth edition of the DSM (DSM-IV; American Psychiatric Association, 1994) criteria. PHAD was coded dichotomously as no parental history of AD (0) and either mother or father was diagnosed with AD (1). Participants were coded as missing if both parents’ information was missing or if one parent did not have an alcohol disorder diagnosis and the other parent’s information was missing. This resulted in 743 participants included in the sensitivity analyses. Parameters of PHAD and its interactions with marital status and age were compared with those from the original model.
