1. National Center for PTSD, Behavioral Science Division, VA Boston Healthcare System, Boston, MA, USA
2. Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA
3. U.S. Department of Veteran Affairs, VA Boston Healthcare System, Boston, MA, USA
4. Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA, USA
5. U.S. Department of Veteran Affairs, VA Palo Alto Healthcare System, Palo Alto, CA, USA
6. Stanford University School of Medicine, Stanford University, Stanford, CA, USA