1 Grey Matter Abnormalities in First Episode Schizophrenia and Affective Psychosis

Background: Grey matter and other structural brain abnormalities are consistently reported in first-onset schizophrenia, but less is known about the extent of neuroanatomical changes in first-onset affective psychosis. Aims: To determine which brain abnormalities are specific to (a) schizophrenia and (b) affective psychosis. Method: We obtained dual-echo (proton density/T2-weighted) MR images and carried out voxel-based analysis on the images of 73 first-episode psychosis patients (schizophrenia=44, affective psychosis=29) and 58 healthy controls. Results: Both patients with schizophrenia and patients with affective psychosis had enlarged lateral and third ventricle volumes. Regional cortical grey matter reductions (including bilateral anterior cingulate gyrus, left insula and left fusiform gyrus) were evident in affective psychosis but not in schizophrenia, although patients with schizophrenia displayed decreased hippocampal grey matter and increased striatal grey matter at a more liberal statistical threshold. Conclusions: Both schizophrenia and affective psychosis are associated with volumetric abnormalities at the onset of frank psychosis, with some of these evident in common brain areas. Declaration of interests: Funding is detailed in acknowledgements