Voxelwise evaluation of white matter volumes in first-episode psychotic bipolar I disorder, unipolar depression and schizophrenia

  • Ms Renata Colombo, Department and Institute of Psychiatry, University of São Paulo, Brazil
  • Dra Maristela Schaufelberger, University of São Paulo, Brazil
  • Ms Luciana Santos, University of São Paulo, Brazil
  • Dr Fabio Duran, Department and Institute of Psychiatry, University of São Paulo, Brazil
  • Prof Paulo Menezes, University of São Paulo, Brazil
  • Dra Marcia Scazufca, University of São Paulo, Brazil
  • Prof Geraldo Busatto, Department and Institute of Psychiatry, University of São Paulo
  • Dr Marcus Zanetti, University of São Paulo, Brazil

Objective: We aim to evaluate regional white matter (WM) volume changes in different affective and non-affective psychotic disorders at their first episode using voxel-based morphometry.
Methods: Individuals presenting with their first psychotic episode of bipolar I disorder (BD-I, n=26), major depressive disorder (MDD, n=20), and schizophrenia/ schizophreniform disorder (n=62) underwent MRI scanning, as well as 94 epidemiologically recruited controls. Images were processed with the Statistical Parametric Mapping (SPM2) package through an optimized routine, and voxelwise exploratory whole-brain comparisons were conducted across groups using an ANOVA model. Post hoc evaluation of significant between-groups findings was then performed with secondary two-tailed t-tests. Only resulting clusters comprising at least 20 voxels, and with peak Z≥3.09 (p<0.001, Family-wise error corrected) were considered significant.
Results: No regional WM abnormalities were observed comparing any of the patients groups (i.e., BD-I, MDD and schizophrenia/ schizophreniform) with controls or across different diagnostic categories.
Conclusions: Psychotic BD-I, psychotic MDD and schizophrenia/ schizophreniform disorder are not associated to WM volume changes at an early course of the illness.