1. Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
2. Department of Psychiatry and Behavioral Science, University of Washington School of Medicine, Seattle, WA, USA
3. Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
4. Group Health Research Institute, Seattle, WA, USA
5. Department of Psychosocial and Community Health, University of Washington School of Medicine, Seattle, WA, USA
6. Department of Neurology, University of Washington School of Medicine, Seattle, WA, USA
7. Swedish Neuroscience Institute, Swedish Medical Center, Seattle, WA, USA