International audienceObjectives Data are scarce regarding the potential clinical differences between non-late onset schizophrenia (NLOS, i.e., disorder occurring before 40 years of age), late-onset schizophrenia (LOS, occurring between ages 40 and 60 years) and very-late-onset schizophrenia-like psychosis (VLOSLP, occurring after 60 years of age). Furthermore, previous research compared LOS patients with non-age matched NLOS patients. In this study, we sought to examine potential clinical differences between patients of similar age with LOS and NLOS. Methods/Design This is a cross-sectional multicentre study that recruited in- and outpatients older adults (aged >= 55 years) with an ICD-10 diagnosis of schizophrenia or schizoaffective disor...