How strong is the evidence for Meditation?

A 2014 JAMA Internal Medicine meta-analysis of meditation programs found moderate evidence for improvements in stress, anxiety and depression symptoms, with effect sizes generally small-to-moderate — a conclusion echoed by later meta-analyses of blood pressure outcomes and brain morphometry. That evidence is currently rated moderate (65/100), built on 10 published studies, including 2 randomized controlled trials and 7 meta-analyses -- a reasonable base, but not yet enough for full certainty.