In Baltimore, in Oregon, and elsewhere, rigorous, developmental, epidemiologically based, randomized field trials have directed interventions at decreasing the early risk factors in the classroom, family, and peer-group settings. These trials indicate that school-based universal interventions (i.e., those addressing all children, not merely those at higher risk) can have short-term beneficial effects on aggressive behavior and achievement (Dolan et al., 1993; Ialongo et al., 1999; Reid, et al., 1999), off-task behavior (Brown, 1994a, 1993b), and depressive symptoms (Kellam, Rebok, Mayer, Ialongo, & Kalodner, 1994). Impact from first grade interventions to reduced aggression in middle school has been reported (Kellam, Rebok, Ialongo, & Mayer [see Appendix-3 for paper], 1994; Kellam, Ling et al., 1998), and delinquency (Eddy et al., 2000). Longer-term effects on illicit drug use have been observed in the Baltimore work (see Figure 1). Reductions in the initiation of tobacco use have been shown as a result of the Baltimore first grade preventive interventions in three separate cohorts (Kellam & Anthony, 1998 [see Appendix-4 for paper]; Storr, Ialongo, Kellam, & Anthony, in press). Longer-term impact has been reported in meta-analyses on illicit drug use by Nan Tobler and colleagues (1986; 2000; Tobler et al., 2000) plus other meta-analyses (Derzon & Lipsey, 1999; Gorman, 1995). Higher-fidelity implementation of the interventions also led to higher impact (Ialongo et al., 1999 [see Appendix-5 for paper], Ialongo, Poduska, Werthamer, & Kellam, 2001 [see Appendix-6 for paper]). Further, we have found compelling evidence that these universal interventions often have the greatest impact on those at highest risk of substance abuse and aggression (Brown & Liao, 1999 [see Appendix-7 for paper]; Curran & Muthèn, 1999; Muthèn & Curran, 1997; Muthèn et al., submitted; Stoolmiller, Eddy, & Reid, 2000 [see Appendix-8 for paper]).