Studies in this issue clarify the negative impact of substance abuse on the health, welfare, and productivity of others. It has been estimated that chemical dependency costs the American public $205 billion a year in lost productivity, crimes, accidents, fires, treatment costs, and various indirect costs. Part 1 provides an indepth discussion of childhood predictors of chemical abuse, including antisocial behavior, school acquiescence, peer influence, and ages at onset of use. Part 2 describes the evolution in prevention over the last decade and various strategies which have withstood scientific investigation. Research projects in school-based initiatives are discussed, as well as family-oriented prevention activities involving parent affective and behavioral training, family skills training therapy, and self-help groups. Part 3 discusses intervention methods which comprehensively encompass the environment of youth, and various treatment approaches applicable and available to youth. Chapter references, tables, footnotes, and author and subject indexes. For individual articles, see NCJ 110668-110676.