The overall goal of "Youth-Focused Media to Prevent Substance Use" is to develop mass media messages that support young people in maintaining a substance-free lifestyle as they move from late childhood into adolescence. Marijuana and cigarette use have risen substantially in recent years, particularly among eighth graders, despite prevention efforts in schools and communities. The media are major sources of information and modeling for young people during adolescence. Previous research has shown that targeted media messages can reduce the prevalence of substance use during early adolescence and that these reductions are sustained through the end of high school. This project will build on and extend this previous research. The major aims are to reduce cigarette and marijuana use among adolescents using targeted media messages broadcast over their preferred media as they mature from grades 4-5 to grades 7-8. Targeted populations include urban samples of African American and white children and non- urban samples of primarily white children. Educational objectives for message development were defined based on social cognitive theory and prior research on psychosocial factors influence adolescence substance use. Messages based on these objectives and on diagnostic research with youngsters in the targeted populations will be pretested before delivery over television and radio to audience segments defined by grade and gender. Pretests will provide information on perceived effectiveness of messages across urban and non-urban samples. Message development cycles will be repeated annually to provide fresh messages as the target group matures over four years. Impact of the messages on targeted and matched comparison areas in one state. Surveys of grade 7-8 students will be conducted in 20 urban and non-urban schools from these areas at baseline and after four years of media exposure in one area to assess impact and outcome expectancies, social-normative perceptions, self- efficacy, and substance use behaviors. Indicators of social climate for substance user use and exposure to school and community programs and mass media campaigns with similar objectives will be assessed in the process evaluation.