C9orf72 and Hallucinations: Delusions, and particularly hallucinations, were significantly less frequent than in C9orf72 and GRN carriers (mean severity score for hallucinations at 0-4 years: 0.02 [95% CI, 0.00-0.04] points in MAPT carriers vs 0.14 [95% CI, 0.06-0.21] points in GRN carriers and 0.41 [95% CI, 0.25-0.57] points in C9orf72 carriers) (Table 2 and Figure 2F).