Common and distinct changes of default mode and salience network in schizophrenia and major depression

• Published in: Brain imaging and behavior Vol. 12; no. 6; pp. 1708 - 1719
• Main Authors: Shao, Junming, Meng, Chun, Tahmasian, Masoud, Brandl, Felix, Yang, Qinli, Luo, Guangchun, Luo, Cheng, Yao, Dezhong, Gao, Lianli, Riedl, Valentin, Wohlschläger, Afra, Sorg, Christian
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2018; Springer Nature B.V
• Subjects: Aberration; Adult; Biomedical and Life Sciences; Biomedicine; Brain; Brain - diagnostic imaging; Brain - physiopathology; Brain Mapping; Depressive Disorder, Major - diagnostic imaging; Depressive Disorder, Major - physiopathology; Female; Functional magnetic resonance imaging; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Mental depression; Mental disorders; Middle Aged; Neural networks; Neural Pathways - diagnostic imaging; Neural Pathways - physiopathology; Neuroimaging; Neuropsychology; Neuroradiology; Neurosciences; Organ Size; Original Research; Patients; Psychiatry; Rank tests; Rest; Salience; Schizophrenia; Schizophrenia - diagnostic imaging; Schizophrenia - physiopathology; Structure-function relationships; Substantia grisea; Schizophrenia; Default mode network; Salience network; Depression; Functional MRI; Diffusion tensor imaging
• ISSN: 1931-7557; 1931-7565; 1931-7565
• DOI: 10.1007/s11682-018-9838-8

Brain imaging reveals schizophrenia as a disorder of macroscopic brain networks. In particular, default mode and salience network (DMN, SN) show highly consistent alterations in both interacting brain activity and underlying brain structure. However, the same networks are also altered in major depression. This overlap in network alterations induces the question whether DMN and SN changes are different across both disorders, potentially indicating distinct underlying pathophysiological mechanisms. To address this question, we acquired T1-weighted, diffusion-weighted, and resting-state functional MRI in patients with schizophrenia, patients with major depression, and healthy controls. We measured regional gray matter volume, inter-regional structural and intrinsic functional connectivity of DMN and SN, and compared these measures across groups by generalized Wilcoxon rank tests, while controlling for symptoms and medication. When comparing patients with controls, we found in each patient group SN volume loss, impaired DMN structural connectivity, and aberrant DMN and SN functional connectivity. When comparing patient groups, SN gray matter volume loss and DMN structural connectivity reduction did not differ between groups, but in schizophrenic patients, functional hyperconnectivity between DMN and SN was less in comparison to depressed patients. Results provide evidence for distinct functional hyperconnectivity between DMN and SN in schizophrenia and major depression, while structural changes in DMN and SN were similar. Distinct hyperconnectivity suggests different pathophysiological mechanism underlying aberrant DMN-SN interactions in schizophrenia and depression.