Efficacy and safety of Xiaoyao pills for mild to moderate depression: study protocol for a randomized controlled trial

BACKGROUND: Depression is one of the most frequent and severe psychiatric conditions. Many chemical drugs to treat depression are associated with adverse reactions and have shortcomings. Traditional Chinese medicine is of great significance in the prevention and treatment of depression. Xiaoyao pills has achieved good results in clinical application, which has the advantages of quick effect and no obvious adverse reactions. The aim of our study is to evaluate the efficacy and safety of Xiaoyao pills on mild to moderate depression patients. METHODS: This study is a multi-centre, double-blinded, randomized and placebo-controlled clinical trial. A total of 108 participants are assigned to three groups: Xiaoyao pill group taking Xiaoyao pills twice daily for 4 weeks, placebo group taking placebos twice daily for 4 weeks and normal group without taking any drug. The primary and secondary outcome measures are the Hamilton Depression Scale (HAMD) and Traditional Chinese Medicine (TCM) Syndrome Scale. The assessment is at baseline (before treatment initiation), 1 week, 2 weeks 4 weeks after the first treatment. Exploratory outcome is also assessed to explore the mechanism of Xiaoyao pills at baseline and 4 weeks. DISCUSSION: The results from this study will provide clinical evidence on the efficacy and safety of Xiaoyao pills in patients with mild to moderate depression with syndrome of liver stagnation and spleen deficiency. TRIAL REGISTRATION: ClinicalTrials.gov ISRCTN12746343. Registered on September 25, 2020.