Currently, we know little regarding the separate effects of parental separation versus parental alcoholism on offspring substance involvement. Two studies examined problem drinking in adult offspring as a function of parental alcohol problems and family structure, and both documented unique risk associated with parental separation (Dube et al., 2002; Thompson et al., 2008). To our knowledge, there is a single study of parental separation and timing of substance use controlling for parental alcoholism. In a predominantly Caucasian Australian sample of twin parents and their children, Waldron and colleagues (2014) examined associations between parental separation and onset of drinking, drinking to intoxication, smoking, regular smoking, and cannabis use. Employing a Children-of-Twins design to control for genetic and environmental risks from parental alcohol and cannabis dependence, parental separation predicted earlier initiation across substance class, with pronounced effects observed during very early adolescence.
