Cortical thickness, gray matter volume, and white matter anisotropy and diffusivity in schizophrenia

Introduction The study was conducted to evaluate simultaneously gray matter changes and white matter changes in patients with schizophrenia. Methods Cortical thickness, gray matter volume, and white matter anisotropy and diffusivity changes in schizophrenic patients (n=21) were assessed relative to age-, gender-, and parental socioeconomic status-matched healthy controls (n=21). We used a newly described semi-automated method (FreeSurfer version 4.5) to determine cortical thickness and gray matter volume and used the tract-based spatial statistics method to evaluate white matter anisotropy and diffusivity. Results Schizophrenic patients showed a significant decrease in hippocampal volume compared with healthy controls. No significant thickness deficits or anisotropy and diffusivity changes were found in schizophrenic patients compared with healthy controls. Stepwise multivariate analysis revealed that hippocampal volume was positively related to duration of illness in schizophrenic patients. Conclusion Our results suggest that hippocampal volume is smaller in schizophrenic patients compared with healthy controls and that progressive hippocampal volume loss occurs in the early course of illness in schizophrenic patients but not in the more chronic stages.