MAPT and Alzheimer disease: The Alzheimer's continuum based on the NIA-AA criteria includes three categories: Amyloid and tau positivity (A + T +) is defined as “Alzheimer’s disease”, and amyloid positivity and tau negativity (A + T −) is defined as “Alzheimer's pathologic change” if neurodegeneration is not present or “Alzheimer's and concomitant suspected non-Alzheimer's pathologic change” if neurodegeneration is present.