On the list of ways in which meditation appears to benefit the brain, depression treatment may be the latest to gain scientific backing. A new review study, out yesterday in the Journal of the American Medical Association (JAMA) Internal Medicine, finds that mindfulness meditation may rival antidepressants in easing the symptoms of depression. The review is noteworthy for this reason: Its authors combed thousands of earlier studies on meditation, arriving at a small number of randomized clinical trials (the gold standard in science) for use in the analysis. Mindfulness meditation may not cure all, the research found, but when it comes to the treatment of depression, anxiety, and pain, the practice may be just as effective as medication.
The team, led by Johns Hopkins’ Madhav Goyal, MD, MPH, looked back over almost 18,000 earlier studies. They ultimately arrived at 47 randomized clinical trials, which together assigned over 3,500 participants to practice meditation (either mindfulness or mantra) or to enroll in another treatment, like exercise. Some define mindfulness as paying attention to one’s internal processes (thoughts and/or bodily sensations) in a curious, but nonjudgmental, way. “A lot of people have this idea that meditation means sitting down and doing nothing,” said Goyal. “But that’s not true. Meditation is an active training of the mind to increase awareness, and different meditation programs approach this in different ways.”
In the current study, the effect size for meditation on depression was found to be moderate, at 0.3.
There was no evidence for an effect of meditation on other measures, like attention, positive mood, substance use, eating habits, sleep and weight. Mantra meditation didn’t seem to carry the same effect as mindfulness meditation, but it may be in part because there were too few studies in the former to draw real conclusions.
But the results are more impressive when you keep in mind that the average effect size of antidepressant medication, the go-to method in the country, is also 0.3. So when it comes to treating depression, which has a notoriously low treatment success rate, the effect size for meditation in the current study is actually pretty impressive.
Asked if he’s encouraged by the results, Goval tells me, “Yes, very encouraged.” Particularly so, he says, since most of the studies included in the review used very short training periods – often eight weeks or less – and one might expect even more robust results with longer training periods. “Compared to other skills that we train in,” he says, “the amount of training received by the participants in the trials was relatively brief. Yet, we are seeing a small but consistent benefit for symptoms of anxiety, depression, and pain. So you wonder whether we might see larger effects with more training, practice, and skill.”
Goval’s next studies will look into this question, along with whether the expertise of the trainer and the length of practice of the trainee have an influence on how meditation might affect depression.
One clear benefit of meditation is that it doesn’t carry the side effects that can accompany drug treatments.
“Also relevant for physicians and patients is that there is no known major harm from meditating, and meditation doesn’t come with any known side effects,” said Goyal. “One can also practice meditation along with other treatments one is already receiving.” It’s important to mention that psychotherapy or talk therapy, particularly cognitive behavioral therapy (CBT), is known to be at least as effective as antidepressants (and the two are most effective when paired).
Though the mechanisms behind the effect of meditation on depression aren’t totally clear, researchers have wagered some guesses. Mindfulness may enhance “attention regulation, body awareness, emotional regulation, and changes in self-perspective (e.g., decentering),” which may all play a role in depression. On a purely biological level, MRI studies have shown that meditation is linked to a reduction in activity in the amygdala, the brain area that governs the stress response, and to reduce activity in the default mode network, the brain network that’s “on” when your mind is wandering from thought to thought, which is often linked to feelings of unhappiness and stress.