1. Department of Family and Preventive Medicine, Emory University School of Medicine, Atlanta, GA, USA
2. Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA
3. Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
4. Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, GA, USA
5. Department of Psychiatry and Behavioral Sciences and the Department of Radiology, Emory University School of Medicine, and the Atlanta VA Medical Center, Decatur, GA, USA
6. Vietnam Era Twin Registry, Seattle, WA, USA
7. University of Washington School of Public Health, Seattle, WA, USA