White and Grey Matter Microstructure Alterations in Early Psychosis and Schizophrenia

In schizophrenia, widespread brain abnormalities are commonly reported but not the microstructure alterations. Here, we investigate brain microstructure during early psychosis and schizophrenia using DKI (in GM & WM), a clinically feasible extension of DTI, and we apply the White Matter Tract Integrity – Watson (WMTI-W, WM only) model. In WM, extensive alterations, consistent with demyelination, were found in early psychosis, while transitioning to chronic schizophrenia, microstructure changes become region-specific as indicated by the two ROI-dependent trends of disease progression found in this cohort. GM showed increased diffusivities and decreased kurtosis, but not widespread as in WM.