C9orf72 and amyotrophic lateral sclerosis: While there is emerging evidence for more extensive overlap across ALS–FTD, C9orf72 and neuropsychiatric disorders, including schizophrenia and autism spectrum disorder (ASD) in terms of shared genetic susceptibility, brain network disruption and co-morbidities [5, 13], the nature of overlap in psychotic symptoms remains poorly understood due to the lack of studies directly comparing these disorders.