A Johns Hopkins University of research suggests that about 30 minutes of meditation daily may improve symptoms of anxiety and depression, without medication.

The scholars evaluated the degree to which self-reported symptoms changed in people who had a variety of conditions, such as insomnia or fibromyalgia. A minority had been diagnosed with a mental illness.

They were studying so-called "mindfulness meditation", a form of Buddhist self-awareness designed to focus precise attention on the moment at hand, and say it shows promise in alleviating some pain symptoms as well as stress. The researchers controlled for the possibility of the placebo effect but it should be noted that reviews of self-reported claims makes statistical reliability difficult.

To conduct their review, the investigators focused on 47 trials performed through June 2013 among 3,515 participants that involved meditation and various mental and physical health issues, including depression, anxiety, stress, insomnia, substance use, diabetes, heart disease, cancer and chronic pain. They found moderate evidence of improvement in symptoms of anxiety, depression and pain after participants underwent what was typically an eight-week training program in mindfulness meditation. They discovered low evidence of improvement in stress and quality of life. There was not enough information to determine whether other areas could be improved by meditation. In the studies that followed participants for six months, the improvements typically continued.

"A lot of people use meditation, but it's not a practice considered part of mainstream medical therapy for anything," says Madhav Goyal, M.D., M.P.H., an assistant professor in the Division of General Internal Medicine at the Johns Hopkins University School of Medicine and lead author of the paper in JAMA Internal Medicine. "But in our study, meditation appeared to provide as much relief from some anxiety and depression symptoms as what other studies have found from antidepressants."

These patients did not typically have full-blown anxiety or depression.

"A lot of people have this idea that meditation means sitting down and doing nothing," Goyal says. "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."

Mindfulness meditation, the type that showed the most promise, is typically practiced for 30 to 40 minutes a day. It emphasizes acceptance of feelings and thoughts without judgment and relaxation of body and mind.

He cautions that the literature reviewed in the study contained potential weaknesses. Further studies are needed to clarify which outcomes are most affected by these meditation programs, as well as whether more meditation practice would have greater effects.

"Meditation programs appear to have an effect above and beyond the placebo," Goyal says.