Frank E. Yeomans, M.D., Ph.D., is Clinical Associate Professor of Psychiatry at Weill Cornell Medical College, Director of Training at the Personality Disorders Institute at Weill Cornell Medical College, and Adjunct Associate Professor of Psychiatry at the Columbia Center for Psychoanalytic Training and Research, New York, New York.John F. Clarkin, Ph.D., is Codirector of the Personality Disorders Institute at Weill Cornell Medical College and Clinical Professor of Psychology in Psychiatry at Weill Cornell Medical College, New York, New York.Otto F. Kernberg, M.D., is Director of the Personality Disorders Institute at Weill Cornell Medical College, Professor Emeritus at Weill Cornell Medical College, and Training and Supervising Analyst at Columbia University Center for Psychoanalytic Training and Research, New York, New York.