1. Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA.
2. Department of Psychology, Central Michigan University, Mount Pleasant, Michigan, USA.
3. Department of Family Medicine and the Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, Illinois, USA.
4. Division of Pulmonary and Critical Care Medicine, Rush University Medical Center, Chicago, Illinois, USA.
5. Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, Illinois, USA.