MAPT and Alzheimer disease: Previous work found an association between greater loneliness (measured with the UCLA Loneliness Scale) and amyloid54, 55 and tau56 positron emission tomography (PET) burden in adults with an average age of 75 at a different period of susceptibility (e.g., preclinical AD) and/or with different measurement (e.g., continuous vs binary biomarkers, amyloid or tau vs amyloid and tau, PET vs pathology).