1. Department of Neuropsychiatry, Kyunggi Provincial Hospital for the Elderly, Yongin, Kyunggi‐do, Korea;
2. Department of Neuropsychiatry, Kangwon National University College of Medicine, Chunchon, Kangwondo, Korea;
3. Department of Occupational Medicine, Hallym University College of Medicine, Anyang, Kyunggi‐do, Korea;
4. Department of Neuropsychiatry, Anyang Metro Hospital, Anyang, Kyunggi‐do, Korea; and
5. Department of Neuropsychiatry, Seoul National University College of Medicine, Seoul, Korea.