The Changes Of First-episode Patients With Mild-to-Moderate Major Depressive Disorder Before And After Cognitive-Behavior Therapy:an FMRI Study

ObjectiveThe study detected the neural changes in first-episode patients with major depressive disorder following cognitive-behavior therapy (CBT) to primarily explore the neurobiological mechanisms of CBT.Method11first-episode treatment-naive patients with major depressive disorder and12matched healthy volunteers underwent both resting state and task state functional magnetic resonance imaging (fMRI) scan. A gender recognition task including neutral, negative and positive facial expression was performed by subjects. Afterward, patients received a6-week CBT and scanned again after treatment. Regional homogeneity (ReHo) in resting-state and the intensities of brain activation during the gender recognition task were analyzed by Rest and SPM8software.ResultsCompared with controls, in resting state, patients exhibited decreased ReHo in right supramarginal gyrus (t=-3.18, P<0.05) and right inferior frontal gyrus(t=-2.99, P<0.05) at baseline, and increased ReHo in middle frontal gyrus(left:t=3.24; right: t=3.06, P<0.05) after treatment; Patients had lower neural responses to negative stimuli in right cerebellum(t=-3.53, P<0.05) and postcentral gyrus(t=-4.31, P<0.05) at baseline, and in vermis(t=-4.07, P<0.05) after treatment; From pre-to post-treatment, in resting state, patients exhibited increased ReHo in hippocampus(t=-3.92, P<0.05); Patients showed increased activation in left fusiform gyrus(t=-5.05, P<0.05), right insula(t=-4.71, P<0.05), left caudate(t=-4.13, P<0.05), right middle frontal gyrus(t=-5.96, P<0.05) and left inferior parietal lobule (t=-5.08, P<0.05) to negative stimuli, and reduced activation in left precentral gyrus(t=4.67, P<0.05), right inferior frontal gyrus(t=5.10, P<0.05) and bilateral supramarginal gyrus(left:t=5.19; right:t=4.81,P<0.05) to positive stimuli.ConclusionsOur findings suggest that short-term CBT may enhance the capability of perception and monitoring to negative emotion engaged by emotional processing and cognitive monitoring system. On the other hand, it may weaken the inhibition of irrelevant information engaged by response inhibition systems to redistribute the processing resources. The interactional outcome of both furthers the harmony of internal and external environment to achieve the therapeutic effect.