This article reports some of the most promising ideas to emerge from a review conducted by the National Institute of Mental Health of the achievements and prospects for research on the prevention of mental disorders. These ideas are organized around 3 conceptual hubs: the development and transformation of biological and social risk and protective factors across the life span, classifying and relating various approaches to preventive interventions in a single logical system, and concepts about community contexts in which prevention trials are executed. These conceptual hubs clarify the relationship between 3 forms of research in prevention: longitudinal studies of risk, randomized preventive intervention trials, and the implementation of successful interventions as part of routine community practice.