Wu Zhou1, Zhong Yuan2, Dai Yingliang2, Xiao Chaoyong3, Zhang Ning3, Wang Chun4. 1. School of Psychology, Nanjing Normal University, Nanjing 210097, Jiangsu, China; Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, 210029, Jiangsu, China. 2. School of Psychology, Nanjing Normal University, Nanjing 210097, Jiangsu, China. 3. Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, 210029, Jiangsu, China. 4. Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, 210029, Jiangsu, China; Functional Brain Imaging Institute of Nanjing Medical University, Nanjing, 210029, Jiangsu, China; Cognitive Behavioral Therapy Institute of Nanjing Medical University, Nanjing, 210029, Jiangsu, China. Electronic address: fm51109@163.com.
Abstract
BACKGROUND: Numerous studies have shown that major depressive disorder (MDD) is characterized by a range of impairments in emotional and cognitive functions that are closely related to abnormalities in brain structure and function. Cognitive behavioral therapy (CBT) can be used as treatment for mild to moderate MDD, which can assist with ameliorating the symptoms. Previous studies have assumed that the internal fluctuations throughout the entire scan are static. However, it has recently been suggested that the brain connectivity is dynamic and relative to continuous rhythmic activity. The effect of dynamic changes in CBT on MDD patients is unknown. METHODS: Nineteen first-episode, unmedicated MDD patients and twenty-two healthy controls (HC) participated in the study. The patients received early CBT treatment once a week for 6 weeks. Symptom examinations and magnetic resonance imaging (MRI) scans were performed pre and post treatment. Degree centrality (DC) was used to investigate the whole-brain connectivity differences between patients with MDD and healthy controls, and sliding window correlation analysis was applied to investigate the dynamic changes of functional connectivity among MDD patients treated with CBT. The variance of dynamic functional connectivity (dFC) was calculated to evaluate the temporal variability along the time. RESULTS: Patients with MDD showed abnormal DC in dorsolateral prefrontal cortex (dlPFC), insula and postcentral gyrus. Correlation analysis revealed that degree centrality of dlPFC was negatively correlated with the course of disease in patients with MDD. Results of dynamic functional connectivity showed that, compared to HC, MDD patients-remained excessively stable in dlPFC and precuneus connectivity, which is associated with emotional cognitive symptoms. After CBT, patients showed increased dFC variability in dlPFC and precuneus (p < 0.01, GRF corrected). CONCLUSION: DLPFC plays an important role in pathophysiological mechanism of MDD. CBT helped patients suppress redundant thoughts and negative self-focus. As a connecting node, dlPFC participates in the mechanism of action of CBT.
BACKGROUND: Numerous studies have shown that major depressive disorder (MDD) is characterized by a range of impairments in emotional and cognitive functions that are closely related to abnormalities in brain structure and function. Cognitive behavioral therapy (CBT) can be used as treatment for mild to moderate MDD, which can assist with ameliorating the symptoms. Previous studies have assumed that the internal fluctuations throughout the entire scan are static. However, it has recently been suggested that the brain connectivity is dynamic and relative to continuous rhythmic activity. The effect of dynamic changes in CBT on MDDpatients is unknown. METHODS: Nineteen first-episode, unmedicated MDDpatients and twenty-two healthy controls (HC) participated in the study. The patients received early CBT treatment once a week for 6 weeks. Symptom examinations and magnetic resonance imaging (MRI) scans were performed pre and post treatment. Degree centrality (DC) was used to investigate the whole-brain connectivity differences between patients with MDD and healthy controls, and sliding window correlation analysis was applied to investigate the dynamic changes of functional connectivity among MDDpatients treated with CBT. The variance of dynamic functional connectivity (dFC) was calculated to evaluate the temporal variability along the time. RESULTS:Patients with MDD showed abnormal DC in dorsolateral prefrontal cortex (dlPFC), insula and postcentral gyrus. Correlation analysis revealed that degree centrality of dlPFC was negatively correlated with the course of disease in patients with MDD. Results of dynamic functional connectivity showed that, compared to HC, MDDpatients-remained excessively stable in dlPFC and precuneus connectivity, which is associated with emotional cognitive symptoms. After CBT, patients showed increased dFC variability in dlPFC and precuneus (p < 0.01, GRF corrected). CONCLUSION: DLPFC plays an important role in pathophysiological mechanism of MDD. CBT helped patients suppress redundant thoughts and negative self-focus. As a connecting node, dlPFC participates in the mechanism of action of CBT.