This study examines the impact of tailored computer-delivered and therapist-delivered brief motivations prevention/interventions both for adolescents who have not initiated marijuana use (prevention), and those who use marijuana (intervention). Key moderators of prevention/intervention effectiveness will be examined, including behavioral intentions, self-efficacy, stage of change, school involvement, susceptibility to peer pressure, and potential health consequences such as STD/HIV risk behaviors. This project will provide the critical first step toward the development and implementation of marijuana use prevention/intervention programs that have the potential to be delivered to a large segment of youth who seek care in our nation's primary care settings.

The primary care setting represents an underutilized venue for prevention interventions addressing drug use/abuse among youth. The purpose of the study is to: (1) develop and refine promising, empirically-derived, BMI prevention/intervention modules delivered by a clinician or a computer to target marijuana use, and (2) test the effectiveness of BMI in preventing initiation/escalation of marijuana use among youth in community health clinics. This randomized controlled trial screened adolescents in primary care clinics in Flint, MI. A random sample of those who screened negative for past year marijuana use were selected to participate in the study and all subjects who screened positive for past year use were enrolled in the study. These subjects were stratified by gender, age, and past year marijuana use and randomized to one of three conditions: 1) computer-delivered brief motivational approach (BMI-C); 2) therapist-delivered brief motivational approach (BMI-T); or 3) a NIDA drug education booklet. Primary outcomes are evaluated at 3-, 6- and 12-months and include marijuana, alcohol, tobacco and other drug use. Key moderators of effectiveness will be examined, including behavioral intentions, self-efficacy, stage of change, school involvement, susceptibility to peer pressure, and potential health consequences (e.g., STD/HIV risk behaviors). This project will provide the critical first step toward the implementation of tailored marijuana prevention and intervention in primary care clinics.

Inclusion Criteria:

• adolescents (ages 12-18) presenting to the approved health clinics (except exclusions as noted below)
• ability to provide informed assent
• access to a parent or guardian for parental consent

Exclusion Criteria:

• adolescents who do not understand English
• adolescents deemed unable to provide informed consent by research staff (e.g., cognitive issues)
• adolescents who come to the clinic because of sexual assault or suicide attempt, or are presenting with high psychological distress requiring intensive attention
• prisoners
• adolescents who are deaf
• adolescents with a sibling or other household member in the study will be excluded from Phase II