1. National Center for PTSD at VA Boston Healthcare System, Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA
2. Department of Psychiatry, Yale School of Medicine and National Center for PTSD, West Haven, CT, USA
3. VA Boston Healthcare System, Boston, MA, USA
4. New England Geriatric Research Education and Clinical Center and Department of Psychiatry, Harvard Medical School, Boston, MA, USA