title: Localized connectivity in depression: a meta-analysis of resting state functional imaging studies.
abstract: Resting-state fMRI studies investigating the pathophysiology of depression have identified prominent abnormalities in large-scale brain networks. However, it is unclear if localized dysfunction of specialized brain regions contribute to network-level abnormalities. We employed a meta-analytical procedure and reviewed studies conducted in China investigating changes in regional homogeneity (ReHo), a measure of localized intraregional connectivity, from resting-state fMRI in depression. Exploiting the statistical power gained from pooled analysis, we also investigated the effects of age, gender, illness duration and treatment on ReHo. The medial prefrontal cortex (MPFC) showed the most robust and reliable increase in ReHo in depression, with greater abnormality in medication-free patients with multiple episodes. Brain networks that relate to this region have been identified previously to show aberrant connectivity in depression, and we propose that the localized neuronal inefficiency of MPFC exists alongside wider network level disruptions involving this region.
authors.affiliation: Centre for Translational Neuroimaging, Division of Psychiatry & Applied Psychology, Institute of Mental Health, University of Nottingham, Triumph Road, Nottingham NG7 2TU, UK. Electronic address: Sarina.Iwabuchi@nottingham.ac.uk.
authors.forename: Sarina J
authors.initials: SJ
authors.lastname: Iwabuchi
authors.affiliation: Psychological Medicine, Sackler Institute, Neurology Block SGH, University of Glasgow, Glasgow G51 4TF, UK. Electronic address: Rajeev.Krishnadas@glasgow.ac.uk.
authors.forename: Rajeev
authors.initials: R
authors.lastname: Krishnadas
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University, Shanghai, China. Electronic address: chunbo_li@163.com.
authors.forename: Chunbo
authors.initials: C
authors.lastname: Li
authors.affiliation: Division of Imaging and Radiological Sciences, University of Nottingham, Nottingham, UK. Electronic address: Dorothee.Auer@nottingham.ac.uk.
authors.forename: Dorothee P
authors.initials: DP
authors.lastname: Auer
authors.affiliation: Institute of Psychiatry, King's College London, UK; FIDMAG Germanes Hospitalàries, CIBERSAM, Barcelona, Spain. Electronic address: Joaquim.Radua@kcl.ac.uk.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Radua
authors.affiliation: Centre for Translational Neuroimaging, Division of Psychiatry & Applied Psychology, Institute of Mental Health, University of Nottingham, Triumph Road, Nottingham NG7 2TU, UK; Nottinghamshire Healthcare NHS Trust, Nottingham, UK. Electronic address: Lena.Palaniyappan@nottingham.ac.uk.
authors.forename: Lena
authors.initials: L
authors.lastname: Palaniyappan
mesh_terms: D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D003866:Depressive Disorder / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009434:Neural Pathways / Q000503:physiopathology; D012146:Rest
keywords: Connectivity; Depression; Effect size – signed differential mapping; Regional homogeneity; Resting-state fMRI