A new study finds that research on mindfulness meditation has yielded moderate evidence that the practice can reduce anxiety, depressive symptoms and pain, but little to no evidence that it can reduce substance abuse or improve mood, sleep or weight control. And no evidence was found that meditation programs were better than drugs, exercise or other behavioral therapies at addressing issues of mental health.
The latest word on meditation's effects comes from a meta-analysis - essentially a study of clinical trials that sifts, consolidates and distills their findings. It was published in JAMA Internal Medicine.
The analysis showed a "small and consistent signal" that different components of negative effect - stress, distress, anxiety and depression -I mproved in subjects who were trained in and practiced mindfulness meditation, the study's authors wrote. The scale of benefits found ranged from 22 percent to 38 percent for anxiety symptoms, and 23 percent to 30 percent for depressive symptoms. Its effect on pain was more robust, yielding an average improvement of about 33 percent.
The authors of the study suggest that little or poorly designed research may have led to their less-than-robust findings in favor of meditation's benefits. Of 18,753 studies of meditation, only 47 were clinical trials designed and conducted with sufficient rigor to be included in the meta-analysis. And the authors cautioned that, despite evidence that the meditator's proficiency matters, there was wide variation in trainer expertise, the amount of training study participants got, and their skill in meditating.
If meditation's widely touted benefits are to win adherents in the examination room, the authors suggested, there will have to be more and better research on meditation, focusing on specific patient populations and looking for well-established outcomes.