A Clinical Trial of Fluvoxamine for Melancholia

This study aims at investigating the special effectiveness of antidepressant effect of Fluvoxamine for endogenous depression. The investigators also aim to assess the effect of Fluvoxamine on the multimodal magnetic resonance imaging(MRI), blood cytokines, feces bacteria flora and neuropsychological performance in depression patients with melancholic features. The investigators further aim to identify the predictors of Fluvoxamine's antidepressant effeect using the above techniques.