The effect of early cognitive behavior therapy for first-episode treatment-naive major depressive disorder

Background: Major depressive disorder (MDD) is one of the most prevalent psychiatric disorders. Cognitive behavioral therapy (CBT) has been widely applied in MDD treatment, yet mechanistic understanding toward CBT remains limited.Methods: Twenty-two MDD patients and twenty-seven matched healthy controls were enrolled. Patients with MDD were given structural early CBT treatment once a week for 6 weeks. Cognitive reconstruction, emotional transformation and behavioral training were included in the treatment process. Local and long-range brain functional connectivity densities (FCD) were obtained to identify abnormal connectivity of MDD by using resting-state functional magnetic resonance imaging (RS-fMRI).Results: After CBT treatment, MDD patients showed increased FCD in the bilateral dorsolateral prefrontal cortex (dlPFC). Functional connectivity (FC) was used to further explore the role of dlPFC in CBT. The results revealed that by the completion of CBT treatment course, the FC between the dlPFC and hippocampus was enhanced.Conclusions: Cognitive behavioral therapy played significant role in alleviating depressive symptoms of MDD patients, evidenced by improved brain connectivity between dlPFC and hippocampus. Further study of dlPFC pathophysiology is needed to better understand these abnormalities in patients with depressive symptoms and the effect of early CBT treatment.