[1] Univ Texas SW Med Ctr Dallas, Dept Psychiat, Mood Disorders Program, Dallas, TX 75390 USA
[2] Massachusetts Gen Hosp, Depress Clin & Res Program, Boston, MA 02114 USA
[3] Univ Texas SW Med Ctr Dallas, Dept Family & Community Med, Dallas, TX 75390 USA
[4] Univ Pittsburgh, Grad Sch Publ Hlth, Epidemiol Data Ctr, Pittsburgh, PA USA
[5] Northwestern Univ, Asher Ctr Study & Treatment Depress Disorders, Feinberg Sch Med, Chicago, IL 60611 USA
[6] Univ Alabama, VA Med Ctr, Tuscaloosa, AL USA
[7] Duke Natl Univ Singapore, Singapore, Singapore