Neural Circuitry of Emotional Processing in Major Depressive Disorder

• Main Authors: Chen-I Shih, 施貞伊
• Other Authors: Kuan-Pin Su
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/20385731807682864823

碩士 === 中國醫藥大學 === 神經科學與認知科學研究所碩士班 === 100 === Objective: Neuroimaging studies of Western depressed patients have reported amygdala hyperactivity and left dorsal lateral prefrontal cortex (DLPFC) hypoactivity in response to negative emotional stimuli. However, there are symptom differences between Caucasian and Chinese. For example, Chinese tend to supress depression or express it somatically. There is no report of the functional magnetic resonance imaging (fMRI) of emotional processing in Taiwanese depressive patients yet. We sought to explore the neural circuitry of emotional processing in Taiwanese patient with major depressive disorder. Method: Thirty-three (9 male and 24 female, mean age=33.21±11 y/s) medication-free patients with major depression and twenty-three (8 male and 15 female, mean age=37.57±8) matched healthy controls participated this study. Each subject was screened by depression inventory before the fMRI scan. We used the block design, in which participants viewed alternating blocks of positive, negative, and neutral pictures during the scan. Results: When contrasting negative with neutral stimuli, depressed patients showed increased activities in left DLPFC (BA46), left orbital frontal cortex (OFC, BA10) and decreased activities in right amygdala as compared to control. In patient group, there were positive correlations of beck dpression inventory (BDI) scores to several neural circuitries, including bilateral DLPFC, bilateral OFC, and bilateral amygdale. In healthy group, BDI scores showed positive correlations to right DLPFC and right amygdala but negative correlation to bilateral OFC. Conclusions: Taiwanese depressive patients exhibited a positive correlation to DLPFC and OFC, regions implicated in emotional regulation and automatic emotional estimate. We suggest that Taiwanese might recruit a compensatory cortical control mechanism over the effect of negative emotional bias in OFC. Future studies will investigate the relationship between clinical manifestations and neural substrates of emotional responses in patients with major depression.