Oriental herbal medicine for generalized anxiety disorder: A systematic review of randomized controlled trials

Abstract

IntroductionGeneralized anxiety disorder (GAD) requires long-term pharmacotherapy, and its recurrence rate is high. Due to several limitations of Western medicine (WM), there are increasing needs for complementary and alternative medicine. The purpose of this review is to examine the effectiveness and safety of Oriental herbal medicine (OHM), medicinal herbs or decoctions prescribed based on Eastern Asian medicine, for GAD. MethodWe conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) assessing the efficacy of OHM for GAD. Twelve electronic databases were searched from inception to 29 January 2018. ResultsA total 109 RCTs were included. Methodological assessments found unclear risks of bias in most the studies. OHM as an alternative monotherapy or adjunctive therapy showed favorable effects: 1) The OHM group had lower Hamilton Rating Scale of Anxiety (HAMA) score than the placebo group, with a mean difference (MD) of −8.35 (95% confidence interval: −12.21 to −4.49; P < 0.0001). 2) The OHM group had lower HAMA score than the WM group, with a MD of −1.46 (−2.25 to −0.66; P = .003). 3) The OHM plus WM group had lower HAMA score than the WM group, with a MD of −2.90 (−3.54 to −2.27; P < 0.00001). There were fewer adverse events in the OHM group than in the WM group. ConclusionsThe results suggest that OHM may have benefits for treating GAD, however, the reliability is severely limited by the overall low quality and marked heterogeneity of the included studies. RCTs of higher quality and longer follow-up periods should be performed.