Topologically convergent and divergent functional connectivity patterns in unmedicated unipolar depression and bipolar disorder

• DOI: 10.1038/tp.2017.117
• Publication Date: 2017-07-04T13:40:44Z
• Authors: Y Wang; J Wang; Y Jia; S Zhong; M Zhong; Y Sun; M Niu; L Zhao; L Zhao; J Pan; L Huang; R Huang
• Keywords: Depression; Limbic system

Bipolar disorder (BD), particularly BD II, is frequently misdiagnosed as unipolar depression (UD), leading to inappropriate treatment and poor clinical outcomes. Although depressive symptoms may be expressed similarly in UD BD, the similarities differences architecture of brain functional networks between two disorders are still unknown. In this study, we hypothesized that II patients would show convergent divergent patterns disrupted topological organization connectome, especially default mode network (DMN) limbic network. Brain resting-state magnetic resonance imaging (fMRI) data were acquired from 32 UD-unmedicated patients, 31 unmedicated (current episode depressed) 43 healthy subjects. Using graph theory, systematically studied their whole-brain at following three levels: whole brain, modularity node. First, both showed increased characteristic path length decreased global efficiency compared with controls. Second, intramodular connectivity within DMN system Third, nodal characteristics (nodal strength efficiency) found predominantly regions DMN, cerebellum whereas also observed precuneus temporal pole. Convergent deficits reflect overlapping pathophysiological processes bipolar depression. Our discovery regional supports emotion processing could help identify biomarkers will aid differentiating these disorders.