1. Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
2. Yokohama Clinic, Warakukai Medical Corporation, Yokohama, Japan
3. Department of Psychiatry, Mie University School of Medicine, Mie, Japan
4. Metropolitan Matsuzawa Hospital, Tokyo, Japan
5. Graduate School of Education, The University of Tokyo, Tokyo, Japan
6. Stanford Center for Sleep Sciences and Medicine, Stanford University School of Medicine, Palo Alto, CA, USA
7. Department of Somnology, Tokyo Medical University, Tokyo, Japan
8. Sleep Research Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan