1. Premedical Courses, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
2. Department of Preventive Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
3. Institute of Health Services Research, Yonsei University, Seoul 03722, Republic of Korea
4. Department of Psychiatry, Yonsei University College of Medicine, Seoul 03722, Republic of Korea