The authors acknowledge and thank all those involved in the data collection of the DSM-IV Field Trial for Psychotic Disorders, across the nine sites in which this study was conducted. Special thanks go to the site coordinators: Xavier Amador, Ph.D., and Jack Gorman, M.D. (New York State Psychiatric Institute, Columbia University, New York); H. Stefan Bracha, M.D. (Department of Psychiatry, University of Arkansas, Little Rock); William Edel, Ph.D., and Thomas McGlashan, M.D. (Yale Psychiatric Institute, Yale University, New Haven, Conn.); Anand Pandurangi, M.D., and Kenneth Kendler, M.D. (Department of Psychiatry, Medical College of Virginia, Richmond); Delbert Robinson, M.D., and Jeffrey Lieberman, M.D. (Department of Psychiatry, Long Island Jewish-Hillside Medical Center, Glen Oaks, N.Y.); Alfonso Ontiveros, M.D., M.Sc. (Department of Psychiatry, Autonomous University of Nuevo Leon, Monterey, Mexico); Mauricio Tohen, M.D., Dr.P.H. (Harvard University, McLean Hospital, Belmont, Mass.); and Patrick McGorry, M.D. (Department of Psychiatry, University of Melbourne, Melbourne, Australia). Finally, Michael Flaum, M.D., Nancy C. Andreasen, M.D., Ph.D., Gary Tyrrell, M.A., and Stephen Arndt, Ph.D. (University of Iowa, Iowa City) played critical roles in the design, data management, and data analysis of the overall field trial project.