AbstractThe design, conduct, and analysis of prevention research efforts present formidable challenges, but as the papers in this volume illustrate, the problems of prevention research are probably not altogether intractable; they simply require the best of our thinking and the firmest of our commitments. The papers included in this issue represent some of the best thinking likely to be available, and, in aggregate, they give reason for some optimism about prevention research. Which is fortunate, because it is by now abundantly clear that treatment of all the assorted personal and social maladies that afflict us individually and as a society, is impossibly intrusive and expensive, even if we were certain we knew what to do, and we are not. Treatment research is only a step or two ahead of prevention research in nearly any field.