Longitudinal Alterations Of Brain Structural Network In Depressions Under Antidepressant Treatment

Major Depressive disorder is a common mental disorder of which the pathological mechanisms still remains unknown. Numerous abnormalities were found in the brains of the patients with depression in previous neuroimaging studies. However, few studies explore the effect of antidepressant treatment on the structural brain networks. Therefore, the main purpose of this paper is to investigate the alternations of topological properties in the brain structural networks of the patients beforeand after treatment The main research contents are summarized as follows:1. We investigated the anatomical structure of the three groups respectively:the group of depression patients without treatment, the group of patients after 8-week treatment, and the group of healthy controls. The modular organization of the patients is reconstructed, and there are significant correlations between clinical scales and modular indexes of some brain regions in DMN (default mode network) and VRN (visual recognition network).2. We explored the rich club organization in depression patients before and after antidepressant treatment. Impaired feeder connections linking rich club nodes and non-rich club nodes were found in depression patients, and the connections were negatively correlated with the duration of disease. Additionally, the capacity of information control and transmission of the Putamen, Cuneus, Hippocampus, Thalamus were found decreased in depression patients, in line with the k-core decomposition analysis.3. Based on the second research, we layered the brain network using rich club theory. Then the topological characteristics of the connections were extracted as classification features. We used support vector machine (SVM) classifier to classify depression patients from the healthy controls, and the untreated patients from the treated ones. The results showed the feature pools with rich club information got better performance than others did, suggesting rich club organization could be served as a type of valuable potential diagnostic measure for major depressive disorder and treatment effects.