Meditative therapies for reducing anxiety: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Anxiety disorders are among the most common psychiatric disorders and meditative therapies are frequently sought by patients with anxiety as a complementary therapy. Although multiple reviews exist on the general health benefits of meditation, no review has focused on the efficacy of meditation for anxiety specifically. METHODS: Major medical databases were searched thoroughly with keywords related to various types of meditation and anxiety. Over 1,000 abstracts were screened, and 200+ full articles were reviewed. Only randomized controlled trials (RCTs) were included. The Boutron (Boutron et al., 2005: J Clin Epidemiol 58:1233-1240) checklist to evaluate a report of a nonpharmaceutical trial (CLEAR-NPT) was used to assess study quality; 90% of the authors were contacted for additional information. Review Manager 5 was used for meta-analysis. RESULTS: A total of 36 RCTs were included in the meta-analysis (2,466 observations). Most RCTs were conducted among patients with anxiety as a secondary concern. The study quality ranged from 0.3 to 1.0 on the 0.0-1.0 scale (mean = 0.72). Standardized mean difference (SMD) was -0.52 in comparison with waiting-list control (p < .001; 25 RCTs), -0.59 in comparison with attention control (p < .001; seven RCTs), and -0.27 in comparison with alternative treatments (p < .01; 10 RCTs). Twenty-five studies reported statistically superior outcomes in the meditation group compared to control. No adverse effects were reported. CONCLUSIONS: This review demonstrates some efficacy of meditative therapies in reducing anxiety symptoms, which has important clinical implications for applying meditative techniques in treating anxiety. However, most studies measured only improvement in anxiety symptoms, but not anxiety disorders as clinically diagnosed.