A Study Of Brain Spontaneous Activity In Treatment-resistant Depression Based On Rs-fMRI

Depression is a kind of mood disorder which is featured by sustained melancholy,hopelessness, and black mood. What is more, it has the characteristics of high incidenceand suicide rate. Though methods and technologies for antidepression have developedrapidly, there are15-30%patients didn’t response to the standard treatment, this part ofpatients is defined as treatment-resistant depression (TDR) patients. Our study appliesthe rest-stating fMRI to TDR to explore the patients’ brain functional changes. We willcarry out our research from two aspects:First, we analyze the brain functional network of TDR to explore the alteration oforganizational attributes. The results show that the functional network of TDR is stillhigh-efficiency small-world network, but the topological properties such as clusteringcoefficient of the network and local efficiency has changed. There are a lot of abnormalfunctional connectives in the network, almost of the abnormal connectives relate toworking memory and information processing. The degree of many brain regions aboutemotional cognitive processing and regulation has abnormally changed. Those resultsimply that the ability for specific information processing, emotional processing andregulation and fault-tolerant of TDR has declined, memory function of TDR has altered.Second, we use fractional amplitude of low-frequency fluctuations (fALFF) toanalyse the abnormal spontaneous functional activities of TDR in two frequency bands(slow-4and slow-5). The abnormal brain regions include prefrontal, inferior temporalgyrus, motor cortex, cerebellum, limbic system and Subcortical regions. The resultssuggest that the TDR’s procession and control of cognition and emotion has changed,those changes may cause patients can’t make proper response to external stimuli. what’smore, the fALFF of left insula is correlated negatively with HAMD at slow-4, rightSuperior gyrus is correlated negatively with course of disease at slow-4, and leftparahippocampal gyrus is correlated positively with course of disease at the two bands.These correlations may be used as biological indicators for diagnosis of TDR.