Common and distinct structural features of schizophrenia and bipolar disorder: The European Network on Psychosis, Affective disorders and Cognitive Trajectory (ENPACT) study

IntroductionAlthough schizophrenia (SCZ) and bipolar disorder (BD) share elements of pathology, their neural underpinnings are still under investigation. Here, structural Magnetic Resonance Imaging (MRI) data collected from a large sample of BD and SCZ patients and healthy controls (HC) were analyzed in terms of gray matter volume (GMV) using both voxel based morphometry (VBM) and a region of interest (ROI) approach.MethodsThe analysis was conducted on two datasets, Dataset1 (802 subjects: 243 SCZ, 176 BD, 383 HC) and Dataset2, a homogeneous subset of Dataset1 (301 subjects: 107 HC, 85 BD and 109 SCZ). General Linear Model analyses were performed 1) at the voxel-level in the whole brain (VBM study), 2) at the regional level in the anatomical regions emerged from the VBM study (ROI study). The GMV comparison across groups was integrated with the analysis of GMV correlates of different clinical dimensions.ResultsThe VBM results of Dataset1 showed 1) in BD compared to HC, GMV deficits in right cingulate, superior temporal and calcarine cortices, 2) in SCZ compared to HC, GMV deficits in widespread cortical and subcortical areas, 3) in SCZ compared to BD, GMV deficits in insula and thalamus (pvs. HC comparison (pConclusionOur study reported both shared and specific neuroanatomical characteristics between the two disorders, suggesting more severe and generalized GMV deficits in SCZ, with a specific role for insula and thalamus.

引言 尽管精神分裂症（schizophrenia, SCZ）与双相障碍（bipolar disorder, BD）存在部分病理特征重叠，但其神经生物学基础仍有待深入探究。本研究针对大样本的精神分裂症、双相障碍患者及健康对照（healthy controls, HC）的结构磁共振成像（structural Magnetic Resonance Imaging, MRI）数据，采用基于体素的形态测量学（voxel based morphometry, VBM）与感兴趣区（region of interest, ROI）两种分析方法，对灰质体积（gray matter volume, GMV）进行了系统分析。方法 本研究基于两个数据集开展分析：数据集1（Dataset1）共纳入802名受试者，其中精神分裂症患者243例、双相障碍患者176例、健康对照383例；数据集2（Dataset2）为数据集1的同质亚组，共包含301名受试者，包括健康对照107例、双相障碍患者85例及精神分裂症患者109例。本研究采用通用线性模型（General Linear Model）完成两项分析：1）全脑体素水平分析（基于体素的形态测量学研究）；2）针对基于体素的形态测量学研究筛选出的解剖脑区开展区域水平分析（感兴趣区研究）。组间灰质体积比较分析同时整合了不同临床维度与灰质体积的相关性分析。结果 数据集1的基于体素的形态测量学分析结果显示：1）与健康对照相比，双相障碍患者右侧扣带回、颞上回及距状皮层存在灰质体积降低；2）与健康对照相比，精神分裂症患者广泛的皮层及皮层下脑区均存在灰质体积降低；3）相较于双相障碍患者，精神分裂症患者的岛叶与丘脑存在灰质体积降低（原文此处统计标注存在截断）。结论 本研究揭示了两种精神障碍共有的及特异性的神经解剖学特征，提示精神分裂症患者存在更为严重且广泛的灰质体积降低，其中岛叶与丘脑发挥了特异性病理作用。