Common gray and white matter abnormalities in schizophrenia and bipolar disorder

Dong-Kyun Lee,Kyeongwoo Park,Hyeongrae Lee,Seunghyong Ryu,Euwon Joh,Chul-Eung Kim,Linda Chao

doi:10.1371/journal.pone.0232826

Dong-Kyun Lee, Kyeongwoo Park + Show 5 more

Open Access

https://doi.org/10.1371/journal.pone.0232826

Copy DOI

Journal: PloS one	Publication Date: May 7, 2020
Citations: 33	License type: CC BY 4.0

Affiliation: Chonnam National University

Abstract

This study aimed to investigate abnormalities in the gray matter and white matter (GM and WM, respectively) that are shared between schizophrenia (SZ) and bipolar disorder (BD). We used 3T-magnetic resonance imaging to examine patients with SZ, BD, or healthy control (HC) subjects (aged 20–50 years, N = 65 in each group). We generated modulated GM maps through voxel-based morphometry (VBM) for T1-weighted images and skeletonized fractional anisotropy, mean diffusion, and radial diffusivity maps through tract-based special statistics (TBSS) methods for diffusion tensor imaging (DTI) data. These data were analyzed using a generalized linear model with pairwise comparisons between groups with a family-wise error corrected P < 0.017. The VBM analysis revealed widespread decreases in GM volume in SZ compared to HC, but patients with BD showed GM volume deficits limited to the right thalamus and left insular lobe. The TBSS analysis showed alterations of DTI parameters in widespread WM tracts both in SZ and BD patients compared to HC. The two disorders had WM alterations in the corpus callosum, superior longitudinal fasciculus, internal capsule, external capsule, posterior thalamic radiation, and fornix. However, we observed no differences in GM volume or WM integrity between SZ and BD. The study results suggest that GM volume deficits in the thalamus and insular lobe along with widespread disruptions of WM integrity might be the common neural mechanisms underlying the pathologies of SZ and BD.

Highlights

Accumulating evidence suggests that schizophrenia (SZ) and bipolar disorder (BD), classically distinct forms of psychosis, may share pathogenic mechanisms
Meta-analyses of voxel-based morphometry (VBM) studies have suggested that there is an overlap between SZ and BD in the areas affected by gray matter (GM) volume reduction including the frontal, temporal, cingulate and insular cortices, and the thalamus, with more extensive GM volume deficits in SZ than BD [12,13,14]
There were no significant differences in age or sex among the 3 groups, but healthy control (HC) had a significantly higher level of education than SZ (P < 0.001) and BD (P < 0.001)

Summary

Introduction

Accumulating evidence suggests that schizophrenia (SZ) and bipolar disorder (BD), classically distinct forms of psychosis, may share pathogenic mechanisms. Several studies have consistently reported a significant overlap in the clinical presentation [1,2], response to pharmacological treatment [3,4], and neurocognitive deficits between the two disorders [5,6]. Brain structure abnormalities in schizophrenia and bipolar disorder. Studies using magnetic resonance imaging (MRI) have provided evidence that there is an overlap in the abnormalities of brain structures in patients with SZ and BD. Meta-analyses of VBM studies have suggested that there is an overlap between SZ and BD in the areas affected by GM volume reduction including the frontal, temporal, cingulate and insular cortices, and the thalamus, with more extensive GM volume deficits in SZ than BD [12,13,14]

Objectives

Methods

Results

Discussion

Conclusion