1. Center for Health Care Evaluation, VA Palo Alto Health Care System, Menlo Park, CA
2. Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
3. National Center for PTSD, VA Palo Alto Health Care System, Menlo Park, CA
4. Center of Excellence in Substance Abuse Treatment and Education, Philadelphia VAMC, Philadelphia, PA
5. Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA