The present study investigated the following in a cohort of participants with PPA and bvFTD due to autopsy-confirmed FTLD-tau: (1) the distinct and shared neuropsychiatric phenotypes of FTLD-tauopathies and (2) whether the presence of certain neuropsychiatric symptoms predicts the odds of specific underlying FTLD-tauopathies. This evidence concerns the gene MAPT and primary progressive aphasia.