Duloxetine's modest short-term influences in subcortical structures of first episode drug-naïve patients with major depressive disorder and panic disorder

We developed this study to follow up the hanges in subcortical structures after 6 weeks' treatment with therapy of duloxetine in first episode drug-naïve patients with major depressive disorder and panic disorder. Fifteen patients received duloxetine 60 mg/d therapy for 6 weeks and achieved remission. They all underwent structural magnetic resonance imaging (MRI) of the brain at baseline and week 6. Fifteen healthy controls were also scanned twice at baseline and week 6 to exclude possible biases. Structural MRI data were preprocessed with FMRIB's Integrated Registration and Segmentation Tool function (FIRST version 1.2) of FSL (FMRIB Software Library; version 4.1.1) to perform subcortical segmentations of the brain using a shape and appearance model. Nonparametric corrections of these structural volumes in an F-test between pre- and post-treatment were used to identify the changes after duloxetine therapy. A false discovery correction of the F-test by FIRST was also performed. A paired t-test using SPSS was applied to confirm the changes in these structures. The patients had consistent changes of volumes in bilateral nucleus accumbens, left putamen, left hippocampus and brainstem after 6 weeks of treatment with duloxetine. There were no consistent changes in other subcortical structures. There were modest increases of the volumes of the above areas, which were not significant after false discovery correction by FIRST F-test comparisons. The volumetric increases were correlated with responses of clinical symptoms. The results suggested that duloxetine possibly contributed to modest increases in several subcortical areas of these patients with remission.