This book presents new and important information about adolescent drug use. The book is intended for human service professionals, teachers, researchers, and students interested in the issue of early adolescent drug use and its causes and pervasiveness in a multiethnic population. Today, the field of adolescent drug use research relies on integrative models that permit competing explanations of drug use. This approach promotes flexibility in testing hypotheses pertinent to adol- cents of very different social and cultural backgrounds or personal characteristics. Longitudinal studies, including the one presented in these pages, have identified many risk and protective factors or processes that are linked to adolescent drug use. We review these throughout this book and present new information from our own research. Our point of departure is to extend and elaborate descriptive research and models of adolescent drug research to cover the unique and diverse experiences of adolescents who are Hispanic, African American, and White non-Hispanic.