[1] VA Boston Healthcare Syst, Natl Ctr PTSD, Boston, MA 02130 USA
[2] Boston Univ, Sch Med, Dept Psychiat, Boston, MA 02118 USA
[3] Boston Univ, Sch Publ Hlth, Dept Epidemiol, Boston, MA USA
[4] Harvard Univ, Dept Psychol, Cambridge, MA 02138 USA
[5] New England Res Inst, Watertown, MA 02172 USA