Wenbin Guo1, Xilong Cui2, Feng Liu3, Jindong Chen2, Guangrong Xie2, Renrong Wu2, Zhikun Zhang4, Huafu Chen3, Jingping Zhao5. 1. Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; National Clinical Research Center on Mental Disorders, Changsha, Hunan 410011, China; National Technology Institute on Mental Disorders, Changsha, Hunan 410011, China; Hunan Key Laboratory of Psychiatry and Mental Health, Changsha, Hunan 410011, China. Electronic address: guowenbin76@csu.edu.cn. 2. Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; National Clinical Research Center on Mental Disorders, Changsha, Hunan 410011, China; National Technology Institute on Mental Disorders, Changsha, Hunan 410011, China; Hunan Key Laboratory of Psychiatry and Mental Health, Changsha, Hunan 410011, China. 3. Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, Sichuan, China. 4. Mental Health Center, The Second Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530007, China. 5. Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; National Clinical Research Center on Mental Disorders, Changsha, Hunan 410011, China; National Technology Institute on Mental Disorders, Changsha, Hunan 410011, China; Hunan Key Laboratory of Psychiatry and Mental Health, Changsha, Hunan 410011, China; Guangzhou Hui Ai Hospital, Affliated Brain Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China. Electronic address: zhaojingping@csu.edu.cn.
Abstract
BACKGROUND: Abnormal default-mode network (DMN) homogeneity has been involved in the neurophysiology of major depressive disorder (MDD) with inconsistent findings. The inconsistency may be due to clinical and methodological variability, and the reproducibility of the findings is limited. The present study aimed to examine alterations of the DMN homogeneity in two independent samples of patients with first-episode, drug-naive MDD. METHODS: The samples included 59 patients with MDD and 31 comparison subjects from Sample 1 and 29 patients with MDD and 24 comparison subjects from Sample 2. Network homogeneity (NH) was computed with an overlapping technique, which was employed to define brain regions with abnormal NH common to the MDD samples. RESULTS: Compared with comparison subjects, patients with MDD exhibited increased NH in an overlapped brain region of the left superior medial prefrontal cortex (MPFC). No correlations were found between abnormal NH and HAMD total/subscale scores in the patients of each sample and in the combined patients from both samples. CONCLUSIONS: This study is the first to examine alterations of DMN homogeneity in first-episode, drug-naive patients with MDD in two independent samples by using an overlapping technique. Patients with MDD exhibit increased NH in an overlapped region in the anterior DMN. The present study thus highlights the importance of the DMN in the neurophysiology of MDD.
BACKGROUND: Abnormal default-mode network (DMN) homogeneity has been involved in the neurophysiology of major depressive disorder (MDD) with inconsistent findings. The inconsistency may be due to clinical and methodological variability, and the reproducibility of the findings is limited. The present study aimed to examine alterations of the DMN homogeneity in two independent samples of patients with first-episode, drug-naive MDD. METHODS: The samples included 59 patients with MDD and 31 comparison subjects from Sample 1 and 29 patients with MDD and 24 comparison subjects from Sample 2. Network homogeneity (NH) was computed with an overlapping technique, which was employed to define brain regions with abnormal NH common to the MDD samples. RESULTS: Compared with comparison subjects, patients with MDD exhibited increased NH in an overlapped brain region of the left superior medial prefrontal cortex (MPFC). No correlations were found between abnormal NH and HAMD total/subscale scores in the patients of each sample and in the combined patients from both samples. CONCLUSIONS: This study is the first to examine alterations of DMN homogeneity in first-episode, drug-naive patients with MDD in two independent samples by using an overlapping technique. Patients with MDD exhibit increased NH in an overlapped region in the anterior DMN. The present study thus highlights the importance of the DMN in the neurophysiology of MDD.