Yoga increases brain gamma-Aminobutyric acid (GABA) activity, which is reduced in mood and anxiety disorders.

Researchers at Boston University School of Medicine studied whether the changes in mood, anxiety, and GABA levels are specific to yoga or simply the result of physical activity.

First, the details.

• Health people with no significant medical or psychiatric disorders were randomly assigned to a treatment group for 60 minutes 3 times a week for 12 weeks.
  • Yoga
  • Metabolically matched walking
• Mood and anxiety scales were recorded before the study and at 4, 8, 12 weeks, and before each magnetic resonance spectroscopy scan obtained at intervals during the study.

And, the results.

• The yoga group reported significantly greater improvement in mood and anxiety compared to the walkers.
• There were positive correlations between improved mood and decreased anxiety and thalamic GABA levels.
  • The thalamus relays sensory impulses to and from the cerebral cortex, which is responsible for voluntary movement, perception, thinking, speaking, etc.
• The yoga group had positive correlations between changes in mood scales and changes in GABA levels.

The bottom line?

The authors concluded, “This is the first study to demonstrate that increased thalamic GABA levels [the main neurotransmitter in the brain] are associated with improved mood and decreased anxiety. It is also the first time that a behavioral intervention (ie, yoga postures) has been associated with a positive correlation between acute increases in thalamic GABA levels and improvements in mood and anxiety scales.

Lead author, Dr. Chris Streeter and colleagues have worked on this concept for several years. In 2007 they reported a 27% increase in GABA levels in a yoga practitioner group but no change in a group following a reading session.

8/29/10 20:41 JR