A review of the published scientific evidence has found that relaxation programs involving meditation offer a small benefit to people with a medical condition, including effects against depression similar in size to those achieved with antidepressant drugs.

The systematic review, published in the internal medicine version of Journal of the American Medical Association, analyzed the results of 47 randomized clinical trials involving a total of 3,515 participants.

The researchers found evidence of “moderate quality” in the medical literature to suggest that mindfulness meditation programs resulted in small improvements in anxiety, depression and pain.

The review was led by Dr. Madhav Goyal, assistant professor of medicine at Johns Hopkins University School of Medicine, Baltimore, MD. Dr. Goyal (resource no longer available at www.hopkinsmedicine.org) has a research interest in the “effects of meditation on chronic pain and symptoms, stress and overall health.”

The study paper concludes:

Our review indicates that meditation programs can reduce the negative dimensions of psychological stress. Mindfulness meditation programs, in particular, show small improvements in anxiety, depression, and pain.”

The mindfulness-based stress-reduction programs in the studies typically provided around 20 to 30 hours of training over 8 weeks.

These emphasized “training in present-focused awareness or mindfulness” and the benefit found was not observed for the other forms of relaxation offered in courses of mantra and transcendental meditation.

The authors of the review say the benefit they found from the mindfulness approach has a part to play in healthcare:

Clinicians should be prepared to talk with their patients about the role that a meditation program could have in addressing psychological stress.”

In addition to the effects of meditation on anxiety and stress, depression, and pain – the review analyzed other emotional and physical outcomes.

The review did not, however, find the same level of meditation benefit in the following areas:

  • Wellbeing
  • The mental component of health-related quality of life
  • Attention
  • Health-related behaviors affected by stress (substance use, sleep, and eating habits were examples)
  • Body weight.

The study authors say that these wider effects have not been tested properly: “Stronger study designs are needed to determine the effects of meditation programs in improving the positive dimensions of mental health and stress-related behavior.”

The positive response to depression was similar to that achieved by antidepressants, the researchers say, with the size of the effect through meditation being up to 52% greater compared with controls.

The size of the effect was up to 44% greater versus controls against anxiety, and up to 31% against pain.

The antidepressant effect of meditation would not be accompanied by the side-effects that can be experienced by people using pharmaceutical drugs, and the review found no evidence of harm created by meditation programs.

All the trials reviewed were in populations of people who had medical or psychiatric conditions, including those with anxiety, depression, stress, chronic worry, and insomnia.

Some trials studied smokers and alcoholics, and others looked at populations with chronic pain. Some 16 of them studied populations with “diverse medical problems, including those with heart disease, lung disease, breast cancer, diabetes mellitus, hypertension, and HIV infection.”

The authors say that medical research has found it “challenging” to study the effects of meditation. They write:

“Training the mind in awareness, in non-judgmental states, or in the ability to become completely free of thoughts or other activity are daunting accomplishments.”

They add:

The interest in meditation that has grown during the past 30 years in Western cultures comes from Eastern traditions that emphasize lifelong growth.

The translation of these traditions into research studies remains challenging.”

The authors outline that meditation is a “skill or state” that is “learned and practiced over time.” Its goal is to gain, through increased awareness, an “insight and understanding into the various subtleties of one’s existence.”

Research published in October 2013 found that mindfulness training helped to lower blood pressure in a trial that saw participants attending weekly 2.5-hour sessions of a mindfulness-based stress-reduction program for 8 weeks. Research in December, meanwhile, found meditation changed gene expression.