Psychiatric and substance use disorders were evaluated using the Semi-structured Assessment for Drug Dependence and Alcoholism (SSADDA; Pierucci-Lagha et al., 2005; Pierucci-Lagha et al., 2007). The most common lifetime DSM-IV (APA, 1994) psychiatric and substance dependence disorders are shown in Table 1. Combined psychiatric comorbidity was defined as having two or more psychiatric diagnoses. The preponderance of participants with multiple psychiatric disorders had only two such disorders, and therefore additional categories reflecting more extensive psychiatric morbidity could not be analyzed. The proband and sibling sub-samples had a comparable distribution of psychiatric diagnoses: 10–15% had histories of each of MDD, ASPD, and PTSD, while 5% had a history of each of panic disorder and agoraphobia or panic disorder and bipolar disorder.
