1. Research Service, VA Boston Healthcare System, Boston, MA, USA
2. Behavioral Neuroscience Program, Boston University School of Medicine, Boston, MA, USA
3. Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
4. Massachusetts Veterans Epidemiology Research and Information Center, VA Boston Healthcare System, Boston, MA, USA
5. Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
6. Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA
7. Military Performance Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
8. Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA
9. Department of Neurology, Boston University School of Medicine, Boston, MA, USA