1. Department of Psychiatry, The Catholic University of Korea School of Medicine, Seoul, Korea.
2. Clinical Research Center for Depression, Seoul, Korea.
3. Department of Preventive Medicine, The Catholic University of Korea School of Medicine, Seoul, Korea.
4. Department of Psychiatry, Keimyung University School of Medicine, Daegu, Korea.
5. Department of Psychiatry, College of Medicine, Korea University, Seoul, Korea.
6. Department of Psychiatry, Chonnam National University Medical School, Gwangju, Korea.