Choroid plexus morphology in schizophrenia and early-stage psychosis: A cross-sectional study

Background: The choroid plexus is an important structure within the ventricular system. Schizophrenia has been associated with morphological changes to the choroid plexus but the presence and extent of alterations at different illness stages is unclear. Methods: We examined choroid plexus volumes in participants at clinical high-risk for psychosis (N = 110), participants with first-episode psychosis (N = 37), participants with schizophrenia (N = 28), clinical (N = 38) and non-clinical controls (N = 75). Automated segmentation (Gaussian mixture model) was used to estimate choroid plexus volumes from T1 magnetic resonance (MR) images. We then conducted a linear model and Bayes factor analysis to investigate group differences. In addition, the relationship between choroid plexus volumes and clinical characteristics was assessed. Results: Schizophrenia patients were characterized by increased choroid plexus and ventricular volume while first-episode psychosis and clinical high-risk for psychosis participants showed no differences in choroid plexus volumes. However, choroid plexus volumes in schizophrenia patients did not significantly differ from controls when controlling for ventricular volume. Finally, choroid plexus volumes were not associated with clinical characteristics in the clinical high-risk group. Conclusion: Our findings suggest that morphological alterations are not specific to the choroid plexus in schizophrenia and early-stage psychosis. Previously reported choroid plexus abnormalities in schizophrenia patients could be explained by changes in ventricular volume.