1. Department of Community Health Nursing, School of Nursing, Faculty of Medicine, Toho University, Tokyo, Japan
2. Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo, Japan
3. Department of Neuropsychiatry, School of Medicine, Kyorin University, Tokyo, Japan
4. Sleep Disorder Research Project, Tokyo Institute of Psychiatry, Tokyo, Japan
5. Aino University, Osaka, Japan