Received Jan. 19, 2005; revision received June 16, 2005; accepted July 12, 2005. From the Department of Psychiatry and Biobehavioral Sciences and Department of Biostatistics, School of Public Health, University of California, Los Angeles; Department of Psychiatry, VA Greater Los Angeles Healthcare System, West Los Angeles Healthcare Center; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas; Department of Psychiatry, University Medical Center Groningen, the Netherlands; Biological Psychiatry Branch, NIMH, NIH, Bethesda, Md.; Psychopharmacology Research Program, Department of Psychiatry, University of Cincinnati College of Medicine, Mental Health Care Line and General Clinical Research Center, and Cincinnati VA Medical Center, Cincinnati; Altrech Institute for Mental Health Care, Utrecht, the Netherlands; and Department of Psychiatry, Ludwig-Maxmilians-Universitat Munich. Address correspondence and reprint requests to Dr. Altshuler, 300 UCLA Medical Plaza, Suite 1544, Box 957057, Los Angeles, CA 90095-7057; firstname.lastname@example.org (e-mail).Supported by the Stanley Medical Research Institute and NIMH. Drug and matching placebo were supplied by GlaxoSmithKline, Pfizer U.S. Pharmaceuticals, and Wyeth Pharmaceuticals.The authors thank Sun Hwang for additional statistical support, Jeffrey Hatef and Sean O’Neill for technical support and randomization tables, and Teri English for administrative assistance.