The bipolar depression patients of 18-55 years old were recruited. At the time of enrollment, the demographic, symptomatic, neuropsychological, neurobiological and genetic data was collected. After the completion of the baseline assessment and examination, the patients were given lithium carbonate or lithium carbonate combined with SSRI antidepressant treatment. Clinical evaluation was performed at 2 and 8 weeks after treatment, including the therapeutic efficacy and adverse drug reactions, and monitoring of serum lithium concentration. The patients further receive the fMRI scans after treatment for 8 weeks. Through above work, this study aimed to provide some guidance for the use of antidepressants in patients with bipolar depression.