1 Department of Psychosomatic Medicine, School of Medicine, International University of Health and Welfare, 4-3, Kozunomori, Narita-shi, Chiba, 286-8686, Japan. m-nakao@iuhw.ac.jp.
2 Fukuoka International University of Health and Welfare, Faculty of Medical Science, Fukuoka, Japan.
3 Department of Psychosomatic Medicine, School of Medicine, The University of Tokyo, Tokyo, Japan.
4 Medical Clinic, Psychosomatics, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm, Berlin, Germany.
5 Department of Behavioral Medicine, Tohoku University Graduate School of Medicine & Department of Psychosomatic Medicine, Tohoku University Hospital, Sendai, Japan.