MAPT and early-onset autosomal dominant Alzheimer disease: Aβ‐positive VR tau‐PET‐negative AD dementia patients (AD A+T−) were compared to tau‐PET‐positive AD patients (AD A+T+) and control groups (CU A−T−; CU A+T−) included from the Amsterdam‐based cohort and Alzheimer's Disease Neuroimaging Initiative (ADNI).