a Graduate Institute of Clinical Medical Science, College of Medicine, China Medical University , Taichung , Taiwan. b Tsaotun Psychiatric Center, Ministry of Health and Welfare , Nantou , Taiwan. c National Changhua University of Education , Changhua , Taiwan. d Department of Psychiatry , Changhua Hospital, Ministry of Health and Welfare , Changhua , Taiwan. e Department of Mathematics , Tamkang University , Taipei , Taiwan. f Feng-Yuan Hospital, Ministry of Health and Welfare , Taichung , Taiwan. g Department of Psychiatry , Harbor-UCLA Medical Center , Torrance , CA , USA. h Department of Psychiatry , China Medical University Hospital , Taichung , Taiwan.