The Kiddie-Schedule for Affective Disorders and Schizophrenia (K-SADS) (Chambers et al., 1985) was administered when the participants were 10 to 12, 12 to 14, and 16 years of age. The Structured Clinical Interview for DSM–III–R (SCID; Spitzer, Williams, Gibbon, & First, 1990) was administered thereafter until age 22. The outcome variables, lifetime AUD and CUD (abuse or dependence), were present in 39.4% and 40.7% of the sample, respectively. This high rate of disorders is consistent with the high-risk family paradigm and the subject inclusion criterion requiring a history of consumption of alcohol and cannabis. The third edition of the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; DSM–III–R; American Psychiatric Association, 1987) was used for diagnosis because this longitudinal project was initiated in 1989 prior to publication of the fourth edition of the DSM (text rev.; DSM–IV–TR; American Psychiatric Association, 2000).
