MAPT and Alzheimer disease: Patients with FTLD-TDP types A and B were more likely to have delusions (32%−35%) compared with patients with AD (16%) or FTLD-tau (2%−15%) pathology.79 Among patients with FTLD-TDP, psychosis was most prevalent among patients with FTLD-TDP type A (53%), followed by type B (42%) and type C (32%).