Participants will travel to Massachusetts General Hospital (MGH) in Boston, MA for a 1-day study visit at enrollment (baseline) and 1-year follow-up. At each visit to MGH, participants will have brain scans, blood tests, and assessments of cognitive performance, psychological health, and physical symptoms. Every 3 months between the baseline and follow-up visits to Boston, there will be brief (\~1 hour) assessments via phone or video teleconference.
