Participants completed the Semi-Structured Assessment for the Genetics of Alcoholism (Bucholz et al., 1994), which includes a diagnostic assessment of DSM-IV (Diagnostic and Statistical Manual of Mental Disorders – Version IV) CD. Participants retrospectively reported on the 15 symptoms of CD that they had experienced before age 18,2 and each symptom was assessed for both seriousness and pervasiveness. The 15 CD symptoms were summed to create a scale indexing the number of symptoms participants experienced before age 18. A sample of 215 randomly selected participants from the 1996-2000 study was selected for retest four years after the main assessment.3 The four-year test-retest reliability for the CD scale was r=.75 (Pearson correlation coefficient), and this test-retest reliability did not differ significantly across sex, t(214) = -0.25, p = .80.
