The effects of meditation on anxiety and stress are comparable to effect sizes described in conventional meta-analyses of psychotherapy field studies. For example Mattick’s (1990) review of psychotherapy for neurotic patients reported a mean effect size of 0.74 for verbal psychotherapy and 0.97 for behavioural psychotherapy vis-a-vis a mean effect size of 0.55 for placebo. My review of meditation on the other hand found a mean effect size of 0.90. It should be noted however that the meditation studies focused on participants with non-pathological anxiety states, raising the possibility that the potential impact of meditation may be limited by a “ceiling effect” due the recruited sample’s relatively mild symptomatology and hence minimal scope for clinical improvement.

Dr Ramesh Manocha