Part I presents data on each of the four problem areas. This includes information on who is at risk for each problem and with what consequences. Quantification of the overlap in these risky behaviors produces estimates of target population for various intervention levels. Part II examines prevention programs in each of the four fields. It extracts workable concepts on program development on which there is consensus among experts. Part III incorporates the ideas generated from the categorical program reviews and presents common concepts to guide the formulation of comprehensive strategies. The book concludes with examples of the application of these principles at the local, State, and Federal levels. The book's overall goal is to provide evidence of a knowledge base from which successful intervention programs can be developed. Important concepts identified are intensive individual attention; social skills training; exposure to the world of work; and broad, communitywide interventions. Schools are identified as the focal institution in prevention. Chapter notes and a subject index