1. Department of General Medicine National Defense Medical College, Saitama, Japan
2. Department of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University Graduate School, Tokyo, Japan
3. Hirasawa Sleep and Mental Clinic, Saitama, Japan
4. International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
5. Ibaraki Prefectural Medical Center of Psychiatry, Kasama, Japan.