Previous studies have suggested that yoga helps to improve stress-related nervous system imbalances. Chris Streeter, from Boston University School of Medicine (Massachusetts, USA), and colleagues submit a neurophysiological theory of how yoga affects the nervous system.

It is hypothesized that stress causes an imbalance in the autonomic nervous system (parasympathetic under-activity and sympathetic over-activity) as well as under-activity of the inhibitory neurotransmitter, gamma amino-butyric acid (GABA). Low GABA activity occurs in anxiety disorders, post-traumatic stress disorder, depression, epilepsy, and chronic pain. The team advances a theory, based on neurophysiology and neuroanatomy, to understand how yoga may be effective in treating patients with stress-related psychological and medical conditions such as depression, anxiety, high blood pressure and cardiac disease. Submitting that: “the decreased [parasympathetic nervous system] and GABAergic activity that underlies stress-related disorders can be corrected by yoga practices resulting in amelioration of disease symptoms.” The study authors conclude, “This has far-reaching implications for the integration of yogabased practices in the treatment of a broad array of disorders exacerbated by stress.”

[C.C. Streeter, P.L. Gerbarg, R.B. Saper, D.A. Ciraulo, R.P. Brown. “Effects of yoga on the autonomic nervous system, gammaaminobutyric- acid, and allostasis in epilepsy, depression, and post-traumatic stress disorder.” Medical Hypotheses, 24 February 2012.]