MAPT and Alzheimer disease: Taken together, our data support the hypothesis that tau positivity allows discrimination of individuals with AD-relevant cognitive decline and suggest that the consideration of incorporating tau PET in tertiary memory clinics could be advantageous since it offers both diagnostic information (45/49 (92%) of T(+) individuals were Αβ(+)) and prognostic insight (since T(+) individuals followed a fast trajectory of cognitive decline).