Complementary and Alternative Medicine Treatments for Generalized Anxiety Disorder: Systematic Review and Meta-analysis of Randomized Controlled Trials

The objective was to evaluate efficacy/safety of complementary and alternative medicine (CAM) methods for generalized anxiety disorder (GAD) based on randomized controlled trials in adults. Data sources. Six electronic databases ("generalized anxiety (disorder)" and "randomized trial") and reference lists of identified publications were searched to March 2017. Study selection. Eligibility: full-text publications (English, German language); CAM versus conventional treatment, placebo/sham or no treatment; GAD diagnosed according to standard criteria; and a validated scale for disease severity. Of the 6693 screened records, 32 were included (18 on biologically-based therapies, exclusively herbal preparations; eight on manipulative and body-based therapies; and three on alternative medical systems and three on mind-body therapies). Data extraction. Cochrane Collaboration methodology was used for quality assessment and data extraction. Direct comparisons of Kava Kava (Piper methysticum) extracts to placebo (4 quality trials, n = 233) were highly heterogeneous. Network meta-regression reduced heterogeneity and suggested a modest Kava effect [end-of-treatment Hamilton Anxiety scale score difference adjusted for baseline scores and trial duration: - 3.24 (95% CI - 6.65, 0.17; P = 0.059), Kava Kava 4 arms, n = 139; placebo 5 arms, n = 359]. Lavender (Lavandula angustifolia) extract (1 quality trial, 10 weeks, n = 523) and a combination of extracts of C. oxycantha, E. californica and magnesium (1 quality trial, 12 weeks, n = 264) were superior to placebo and balneotherapy was superior to paroxetine (1 quality trial, 8 weeks, n = 237) indicating efficacy. All other trials were small and/or of modest/low quality and/or lacked assay sensitivity. Safety reporting was poor. Evidence about efficacy/safety of most CAM methods in GAD is limited. Apparent efficacy of certain herbal preparations and body-based therapies requires further confirmation.