Clinical Efficacy of the Chinese Herbal Medicine Shumian Capsule for Insomnia: A Randomized, Double-Blind, Placebo-Controlled Trial

PURPOSE: Shumian capsule (SMC) is a patent Chinese herbal medicine that can soothe the liver and relieves depression, quiet the spirit. Here, we aimed to investigate the efficacy of SMC for treating insomnia using both scales and polysomnography (PSG). PATIENTS AND METHODS: A randomized, double-blind, placebo-controlled trial was performed. Twenty-six insomnia patients randomly received SMC (n = 11) or placebo (n = 15) for four weeks. Pittsburgh Sleep Quality Inventory (PSQI), Insomnia Severity Index (ISI), 9-items Patient Health Questionnaire (PHQ-9), 7-items Generalized Anxiety Disorder (GAD-7), 17-item Hamilton Depression Rating Scale (HAMD-17), and Hamilton Anxiety Rating Scale (HAMA) were applied at the baseline and the 2nd, 4th week after treatment. Treatment Emergent Symptom Scale was used to assess adverse reactions. We used PSG to record and analyze sleep features at baseline and after four weeks. RESULTS: PSQI, ISI, PHQ-9, HAMD-17, and HAMA scores decreased significantly after SMC treatment. Also, the total sleep time, rapid-eye-movement (REM) sleep latency, stage 2 sleep, deep sleep, REM sleep, and sleep efficiency improved significantly after SMC treatment. In the placebo group, the only significant change was the decrease of PHQ-9 at week-2. Furthermore, both SMC and placebo reported no adverse events. CONCLUSION: SMC could safely improve sleep quality with depression and anxiety remission in insomnia patients.