Nothing less than the future of psychiatric diagnosis is at stake as the American Psychiatric Association undertakes the process of research, evaluation, and analysis that will eventuate in publication of DSM-V in 2012. This new collection, Dimensional Approaches in Diagnostic Classification: Refining the Research Agenda for DSM-V, transcends the current categorical definitions set forth in DSM-III and DSM IV and suggests ways of incorporating more quantitative concepts into DSM-V.The proceedings of a conference convened by the APA, in collaboration with the World Health Organization and the U.S. National Institutes of Health, the book explores a dimensional approach to diagnosing substance dependence, major depressive episode, psychosis, anxiety disorders, developmental psychopathology, and personality disorders. The authors present a critical appraisal of dimensional approaches in diagnostic classification and an examination of categories and dimensions in clinical and research contexts.Clinicians and researchers in the United States and the international psychiatric community will discover, in these pages, the beginnings of a new, quantitative methodology that will transform diagnosis and represents the next stage in the evolution of DSM.