Hagop S. Akiskal, MD, FAPA, is Professor of Psychiatry and Director of the International Mood Center at the University of California, San Diego, and editor-in-chief of the Journal of Affective Disorders. The recipient of the clinical research award of the American Academy of Clinical Psychiatrists (1981) and the Samuel G. Hibbs Award of the American Psychiatric Association (1989) for his work on chronic depression, Dr. Akiskal has also been honored with the Gold Medal of the Society of Biological Psychiatry (1995). Prior to his current post, he was Senior Science Advisor to the Director of the National Institute of Mental Health. Giovanni B. Cassano, MD, FRCP, is Professor of Psychiatry and… Director of the Institute of Psychiatry at the University of Pisa, Italy. A leading European psychiatrist combining expertise in both academic and clinical psychiatry, Dr. Cassano, with his Pisan colleagues, has advanced our understanding of the spectrum concepts in mood and anxiety disorders. He is the author of a best-selling book on depression for the Italian public.