[1] Seoul Natl Univ, Bundang Hosp, Dept Neuropsychiat, Songnam 463707, Gyeonggi Do, South Korea
[2] Korean Armed Forces Capital Hosp, Dept Psychiat, Gyeonggi Do, South Korea
[3] Seoul Vet Hosp, Dept Psychiat, Seoul, South Korea
[4] Seoul Natl Univ, Coll Med, Dept Psychiat, Seoul, South Korea
[5] Univ Calif San Diego, Sch Med, Div Pulm & Crit Care Med, San Diego, CA 92103 USA