1. Department of Psychiatry; Nihon University School of Medicine; Tokyo Japan
2. Department of Public Health and Epidemiology; Faculty of Medicine, Oita University; Oita Japan
3. Division of Public Health, Department of Social Medicine; Nihon University School of Medicine; Tokyo Japan
4. Division of Respiratory Medicine, Department of Internal Medicine; Nihon University School of Medicine; Tokyo Japan
5. Division of Sleep Medicine, Department of Internal Medicine; Nihon University School of Medicine; Tokyo Japan