Received May 27, 2003; revision received Jan. 30, 2004; accepted Feb. 12, 2004. From the Department of Psychiatry, University of Pittsburgh, and the Price Foundation Collaborative Group. Address reprint requests to Dr. Kaye, Department of Psychiatry, University of Pittsburgh Medical Center, Western Psychiatric Institute & Clinic, 3811 O’Hara St., Suite 600, Iroquois Bldg., Pittsburgh, PA 15213; firstname.lastname@example.org (e-mail). Support for the clinical collection of subjects and data analysis provided by the Price Foundation. The authors thank the staff of the Price Foundation Collaborative Group for their efforts in participant screening and clinical assessments, Eva Gerardi, and the participating families for their contribution of time and effort in support of this study. The Price Foundation Collaborative Group includes Walter H. Kaye, M.D., Laura Thornton, Ph.D., Nicole Barbarich, B.S., Kim Masters, B.S., Katherine Plotnicov, Ph.D., Christine Pollice, M.P.H., and Bernie Devlin, Ph.D., Department of Psychiatry, University of Pittsburgh; Cynthia M. Bulik, Ph.D., Department of Psychiatry, University of North Carolina at Chapel Hill; Manfred M. Fichter, M.D., and Norbert Quadflieg, Dipl.Psych., Klinik Roseneck, Hospital for Behavioral Medicine, affiliated with the University of Munich, Prien, Germany; Katherine A. Halmi, M.D., New York Presbyterian Hospital, Weill Medical College of Cornell University, White Plains, N.Y.; Allan S. Kaplan, M.D., and D. Blake Woodside, M.D., Program for Eating Disorders, Toronto General Hospital, Toronto; Michael Strober, Ph.D., Department of Psychiatry and Behavioral Science, University of California at Los Angeles; Andrew W. Bergen, Ph.D., Biognosis, U.S., Inc., and Core Genotyping Facility, Advanced Technology Center, National Cancer Institute, Gaithersburg, Md.; Scott Crow, M.D., Department of Psychiatry, University of Minnesota, Minneapolis; James Mitchell, M.D., Neuropsychiatric Research Institute, Fargo, N.D.; Alessandro Rotondo, M.D., Department of Psychiatry, Neurobiology, Pharmacology and Biotechnologies, University of Pisa, Italy; Mauro Mauri, M.D., University of Pisa, Italy; Pamela Keel, Ph.D., Department of Psychology, Harvard University, Cambridge Mass.; Kelly L. Klump, Ph.D., Department of Psychology, Michigan State University, East Lansing; Lisa R. Lilenfeld, Ph.D., Department of Psychology, Georgia State University, Atlanta; and Wade H. Berrettini, M.D., Center of Neurobiology and Behavior, University of Pennsylvania, Philadelphia.