Participants were interviewed on the lifetime use of alcohol and each drug that they had taken (including nicotine) using a timeline follow-back and lifetime drinking history assessment (Skinner and Allen, 1982, Skinner and Sheu, 1982, Sobell and Sobell, 1992, Sobell et al., 1988). ASPD symptoms were obtained using the C-DIS (Blouin et al., 1988, Robins et al., 1998). For each symptom the subject endorsed, we asked about currency. Psychological measures of antisocial behavior were also assessed. Social deviance proneness was measured by the CPI socialization scale (Gough, 1994), impulsivity was measured by the Eysenck impulsivity scale (Eysenck and Eysenck, 1975), and antisocial disposition was measured by the MMPI psychopathic deviance scale (Hathaway and McKinley, 1989). Group comparisons on clinical and psychological measures were examined using the General Linear Model within SPSS (SPSS Inc. 2009). Measures of effect size are the odds ratios for rate data and partial η2 (proportion of variance of the dependent variable independently accounted for by group) for symptom counts, psychological measures and other demographic variables.
