Abnormal regional brain activity in patients with first-episode medication-naïve depressive disorder: A longitudinal fNIRS study

The potential relationship between abnormal brain activity and clinical symptoms in patients with major depressive disorder (MDD) is important for auxiliary diagnosis and prediction of the curative effect of treatments for MDD. Before antidepressant treatment (T1), 4 weeks after treatment (T2), and 8 weeks after treatment (T3), 33 patients with first-episode medication-naïve MDD and 30 healthy controls (HCs) were examined using functional near-infrared spectroscopy (fNIRS) to evaluate the cerebral hemodynamic response in the frontal and temporal cortex during the Verbal Fluency Task (VFT). Compared with HCs, VFT scores and activation levels of the frontal pole, inferior frontal gyrus, and dorsolateral prefrontal cortex were significantly decreased in the first-episode medication-naïve depressive disorder patients (FMD). Compared with T2, the activation levels of the superior temporal gyrus and inferior central gyrus were increased at T3 in the FMD. The low activation pattern of the frontal pole, inferior frontal gyrus, and dorsolateral prefrontal cortex in the FMD during VFT is helpful for clinical diagnosis of MDD. The superior temporal gyrus and inferior central gyrus may be sensitive brain regions that reflect the clinical effect of MDD in patients.