Yoga Might Fight Depression and Anxiety
Activity appears to boost levels of a key chemical in the brain

(HealthDay News) -- Already popular as a means to tone the body and soothe the soul, yoga appears to create a change in the brain that some believe might ease depression and anxiety.

Researchers found that immediately after a one-hour yoga session, practitioners showed a significant increase in the levels of a chemical in the brain -- the neurotransmitter gamma-aminobutyric, or GABA. Low levels of GABA in the brain are associated with anxiety and depression.

The study included eight people who'd practiced yoga for many years and 11 who had never done yoga. All were healthy, and none had been diagnosed with a major psychiatric condition. Magnetic resonance spectroscopic imaging scans of all the participants' brains were taken before the testing started.

The yoga practitioners then did a one-hour session while the non-practitioners read. This was followed by a second round of brain scans.

"We showed a 27 percent increase in the brain GABA levels of those doing yoga -- a really significant increase," the study's leader, Dr. Chris Streeter, an assistant professor of psychiatry and neurology at the Boston University School of Medicine, told HealthDay . There was no increase in the participants who just read.

"I am quite sure that this is the first study that's shown that there's a real, measurable change in a major neurotransmitter with a behavioral intervention such as yoga," Streeter said. The findings were published in the Journal of Alternative and Complementary Medicine .

Although Streeter said she believes that yoga could help people fight depression and anxiety disorders, she said the researchers aren't "advocating that they chuck their medication, but I would advise that they could use [yoga] as an adjunct and see how they are doing."

One expert pointed to several possible flaws in the study. For one, the yoga group was compared with a sedentary reading group rather than with people doing another type of physical activity.

"Exercise itself may have some effects on GABA, so I think in this study you'd really want that comparison," Zindel Segal, chairman of psychotherapy and a professor of psychology and psychiatry at the University of Toronto , told HealthDay .

He also noted that all the participants were mentally healthy. Clinical depression and anxiety disorders involve more than the "daily fluctuations in stress and tension" that may afflict healthy people, he said.

GABA might play a role in anxiety disorders, Segal said, but he questioned its role in depression.

"GABA is not one of the main neurotransmitters that seems to be a part of the depression story," he said. Other neurochemicals -- most notably serotonin -- are much bigger factors in depression.

While he did find flaws in the study, Segal also said that it has merits and that the findings suggest the need for more research into this area. He described the study as a starting point.

"I think what's important about this study is that it shows that by using really cutting-edge neuroimaging technology, we can measure real changes in the brain with behavioral interventions -- changes that are similar to those that we see with pharmacologic treatments," he said.

On the Web

Learn more about depression by visiting the U.S. National Institute of Mental Health.

SOURCES: HealthDay News ; Chris Streeter, M.D., assistant professor of psychiatry and neurology and director of functional neuroimaging for psychiatry, Boston University School of Medicine; Zindel Segal, Ph.D., Morgan Firestone chair in psychotherapy, and professor of psychiatry and psychology, University of Toronto, Canada; May 2007, Journal of Alternative and Complementary Medicine
Author: Robert Preidt
Publication Date: June 30, 2008
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