Associations among plasma ptau181, tau PET, and amyloid PET in a community‐based study during midlife

The amyloid‐tau‐neurodegeneration (AT(N)) research framework uses a biomarker definition of Alzheimer’s disease (AD); neuroimaging has been the in vivo gold standard, but plasma‐based measures are becoming more widely available yet need to be characterized earlier in the life course and AD continuum, as well as in representative samples. Our objective was to understand how plasma measures of ptau181 correspond with PET‐derived measures of amyloid and tau in middle age.