Comparing groups, hallucinations and delusions were more frequent and severe in the C9orf72 group: visual hallucinations frequency 23.6%, severity 0.26 (0.58) vs 7.7%, 0.10 (0.36) in GRN mutation carriers and 8.0%, 0.06 (0.22) in MAPT mutation carriers; auditory hallucinations 22.2%, 0.31 (0.71) vs 7.7%, 0.06 (0.21) and 0.0%, 0.00 (0.00); tactile hallucinations 9.7%, 0.14 (0.53) vs 0.0%, 0.00 (0.00) and 4.0%, 0.02 (0.10); delusions 36.1%, 0.51 (0.81) vs 17.3%, 0.13 (0.36) and 12.0%, 0.16 (0.47). Here, GRN is linked to Visual hallucination.