1990; Pentz, MacKinnon, et al., 1989a, 1989b; Pentz, Trebow, et al., 1990). The intervention included the following: (1) classroom curriculum targeting students in sixth and seventh grades, (2) parent training addressing prevention policy and parent–child communication skills, (3) training of community leaders in development of a drug abuse prevention task force, and (4) media promotion of prevention policies and norms (Pentz, MacKinnon, et al., 1989b). The intervention was evaluated in a quasi-experimental trial and a subsequent experimental trial. In the formal trial, the intervention was equally effective for both high- and low-risk youth (Johnson, Pentz, et al., 1990). In the latter trial, there was significantly less tobacco and marijuana (but not alcohol) use in the MPP schools than in control schools, with effects found primarily in private and parochial schools (Pentz, Trebow, et al., 1990); through 3.5 years postbaseline, the percentage of students with reports of substance abuse during the past month declined from one assessment to the next (Chou, Bentler, and Pentz, 1998). MPP produced significant declines in cigarette, alcohol, and marijuana use across all follow-ups. There were limited effects for baseline marijuana users and diminishing effects for early alcohol and cigarette users over time.
Project Northland was a multimodal intervention aimed at delaying the onset of and reducing underage drinking (Perry, Williams, et al., 1996; Perry, Williams, and Komro, 2000, 2002). It was initially evaluated in a randomized trial of 24 small Minnesota communities and subsequently in a randomized trial in Chicago inner-city schools. The intervention included social-environmental approaches and individual behavior change strategies along with community organizing, youth action teams, print media regarding healthy norms about underage drinking, parent education and involvement, and classroom-based social-behavioral curricula. In the Minnesota trial, alcohol use was prevented among 8th grade students, and those who were not using alcohol at the beginning of the project reported significantly less alcohol, marijuana, and cigarette use at the end of 8th grade. The effects were not maintained by the time students were in 10th grade. The results were not replicated in the Chicago trial (Komro, Perry, and Veblen-Mortenson, 2008).
Other programs have focused primarily on changing community policies and norms. Communities Mobilizing for Change on Alcohol developed a social-environmental intervention to reduce underage alcohol access through changes in policies and practices of major community institutions (Wagenaar, Murray, et al., 2000). Strategy teams comprised community groups and organizations focused on decreasing the number of alcohol outlets selling to youth, reducing access to alcohol from noncommercial sources (e.g., parents, siblings, peers), and changing cultural norms that tolerate underage access to and consumption of alcoholic beverages. Fifteen communities in Minnesota and Wisconsin were randomized into interven-