Efficacy and safety of traditional Chinese medicine for Tourette's syndrome: A meta-analysis of randomized controlled trials

Background: Traditional Chinese medicine (TCM) has been widely used in the treatment of Tourette's Syndrome (TS). However, the efficacy and safety of TCM in treating TS are mixed across studies. This is a meta-analysis of studies on the efficacy and safety of TCM compared to placebo and Western medicine (WM). Methods: PubMed, Cochrane Library, PsycINFO, Chinese National Knowledge Infrastructure, SinoMed, and WanFang databases were systematically searched from inception date to October 16, 2018. Randomized Controlled Trials (RCTs) on the efficacy and safety of TCM alone or TCM + WM combination for TS were included. Results: A total of 15 studies comprising 21 treatment trials (n = 2824) were included. TCM alone was more efficacious than placebo in terms of response rate (Relative Risk, RR: 1.96, 95% CI: 1.55–2.47, P < 0.01, I² = 45 %) and the change in the Yale Global Tic Severity Scale total score (Standard mean difference, SMDs: -0.67, 95% CI: -0.81, -0.53, P < 0.01, I² = 0 %). The results remained positive when TCM alone was compared with WM alone (RR: 1.06, 95% CI: 1.00–1.12, P = 0.03, I² = 29 %), and when TCM + WM were compared with WM alone (RR: 1.24, 95% CI: 1.08–1.43, P < 0.01, I² = 0 %). Adverse drug reactions were more frequent in WM than in TCM groups (P < 0.05). WM type (P = 0.02), proportion of males (P = 0.03) and trial duration (P = 0.03) were significantly associated with response rate in TS patients when comparing TCM alone with WM alone. Conclusion: The results of this meta-analysis support the efficacy and safety of TCM alone and TCM + WM in TS patients.