1. Department of NeurologyCollege of Medicine, Mayo ClinicRochesterMNUSA
2. Mayo Alzheimer's Disease Research Center, Mayo ClinicRochesterMNUSA
3. Division of Epidemiology, Department of Health Sciences ResearchCollege of Medicine, Mayo ClinicRochesterMNUSA
4. Group Health Research InstituteSeattleWAUSA
5. Department of PsychiatrySchool of Medicine, University of PittsburghPittsburghPAUSA
6. Department of EpidemiologyGraduate School of Public Health, University of PittsburghPittsburghPAUSA