Meditation techniques that regulate attention or construct personal values are slightly more effective than relaxation therapy for reducing anxiety. A meta-analysis of 14 randomized controlled trials with 862 participants suffering from anxiety disorders or high trait anxiety found a small effect favoring meditation (Hedges' g = −0.23). The number needed to treat was 7.74. Heterogeneity among studies was low, and there was no evidence of publication bias, though few studies were of high quality and researcher allegiance may have influenced results. Meditation may remain more effective at 12-month follow-up, but more research is needed across the full range of meditation practices and anxiety disorders.
A meta-analysis of 23 randomized controlled trials with 1,373 tertiary education students found that meditation, yoga, and mindfulness interventions produced moderate reductions in depression, anxiety, and stress at post-test (effect sizes g = 0.42–0.46). However, when compared to active control conditions, the effect dropped to a small, non-significant g = 0.13. Most studies had a high risk of bias, no trial reported on safety, and only two examined academic achievement. The authors caution that the overall poor quality of the evidence means results should be interpreted with care, and it remains unclear whether these interventions affect academic outcomes or have negative side effects.