[1] Inst Mental Hlth, Dept Gen Psychiat 1, Singapore, Singapore
[2] Duke NUS Grad Med Sch, Off Clin Sci, Singapore, Singapore
[3] Univ Toronto, Ctr Addict & Mental Hlth, Div Schizophrenia, Toronto, ON M5S 1A1, Canada
[4] Univ Toronto, Dept Psychiat, Toronto, ON M5S 1A1, Canada