According to The Johns Hopkins Winter 2008 Issue of Depression and Anxiety Bulletin:

Low levels of the neurotransmitter gamma-aminobutyric acid (GABA) have been associated with depression and particularly anxiety, and antidepressants have been shown to increase GABA levels. Now, preliminary research suggests that the regular practice of yoga may be an effective, nonpharmacological way to raise GABA levels and potentially improve anxiety and depression symptoms. 

Researchers recruited eight longtime yoga devotees who practiced twice a week for at least four months and 11 comparison participants. Both groups had a baseline brain scan done. Then the yoga participants performed a one-hour yoga session while the control group read books or magazines [or packed snacks for their kids so they wouldn’t be yelled at] for the same time, and all participants were rescanned immediately after.

The yoga volunteers showed a 27 percent increase in GABA levels compared with baseline, but there was no change among the readers [or snack-packers].

Several previous trials have demonstrated that yoga can reduce anxiety and depression symptoms, but this is the first study to identify a possible mechanism for the effects.

The investigators conclude that yoga may serve as a useful adjunct to standard treatments recommended by your doctor. This research was published in the Journal of Alternative and Complementary Medicine.

To read more Beyond Blue, go to www.beliefnet.com/beyondblue, and to get to Group Beyond Blue, a support group at Beliefnet Community, click here.