1. Graduate School of Medicine, Kyung Hee University, Seoul 02543, Korea
2. Kyung Hee University School of Medicine, Seoul 02543, Korea
3. Department of Psychiatry, Kyung Hee University Hospital, Seoul 02447, Korea
4. Department of Psychiatry, Seonam University, College of Medicine, Myongji Hospital, Goyang 10475, Korea
5. Department of Psychiatry, Kyung Hee University School of Medicine, Seoul 02447, Korea