B. Background and Significance Over the past three decades, evidence from developmental epidemiological studies has consistently identified specific antecedent risk factors at least as early as first grade as predictive of later substance abuse and comorbid mental and behavioral disorders during the middle school years and beyond (Cairns, Cairns, & Neckerman, 1995; Farrington, 1995; Hawkins, Catalano, & Miller, 1992; Hawkins, Doueck, & Lishner, 1988; Kellam, Brown, Rubin, & Ensminger, 1983; Reid, 1993; Reid & Eddy, 1997). Many of these antecedents are exhibited in the school setting, such as aggressive, disruptive behavior in first grade and its strong correlate, poor academic achievement. These early risk factors can lead to later substance abuse and school dropout, which have considerable economic, social, and psychological consequences (Dishion, Capaldi, & Yoerger, 1999; Eddy, Reid, & Fetrow, 2000; Hawkins et al., 1992; Kellam et al., 1983; Kellam, Mayer, Rebok, & Hawkins, 1998; Maguin & Loeber, 1996; Mrazek & Haggerty, 1994; Reid, Eddy, Fetrow, & Stoolmiller, 1999 [see Appendix-1 for paper]). These risk factors are also strongly related to a host of other risk factors that separately or together are predictive during adolescence and young adulthood of not only drug abuse, but also conduct disorders and violence, depression, school drop out, and high-risk sexual behaviors. Ineffective parenting around discipline and homework; classrooms with high levels of aggressive, disruptive behavior; antisocial classmates and peers; poverty at the family level and at the school and community levels, and individual differences such as sensation seeking (Wills, Sandy, & Yaeger, 2000; Palmgreen, Donohew, Lorch, Hoyle, & Stephenson, 2001)—all have been found to increase the risk of drug abuse and related comorbid problems (Ary et al., 1999; Dishion et al., 1999; Kellam, Ling, Meriska, Brown, & Ialongo, 1998 [see Appendix-2 for paper]; Reid, Patterson, & Snyder, in press).