Thus, yoga practices are effective when they correct underactivity of the parasympathetic
nervous system and GABA system through stimulation of the vagal nerves and reduce
alostatic load. Depression, epilepsy, PTSD and chronic pain all respond to vagal nerve
stimulation and to pharmaceuticals that improve brain GABA activity. They also show
improvement in response to yoga practices.^6
- Hatha Yoga^7 (in the US commonly called "yoga"), as it originated in India, consists of a
system of spiritual, moral and physical practices. Two central and common aspects of yoga
practice today are physical postures (asanas) and breathing exercises (pranayamas). These
breathing exercises aim to focus the mind, facilitate relaxation and enhance wellness.
Evidence suggests that these practices result in physiological effects such as increased
parasympathetic drive, calming of stress response systems, release of hormones, and
modulation of thalamic generators. The thalamus (located in the third ventricle of the brain)
plays a critical role in the anatomy of mood and emotion.
- EFFICACY: A review of the literature evaluating the different forms of yoga suggests
potential beneficial effects for depressive disorders, anxiety, stress reduction and general
well-being. As stated by Brown et al., the most “authoritative” source, “both optimistic and
cautious,” is Pilkington, Kirkwood, Rampes. & Richardson, “Yoga for Depression: the
Research Evidence” (2005).^8 However, the underlying trials were small and uncontrolled.
- DEPRESSION
As of 2005, there were five randomized controlled trials of the use of yoga to alleviate
depression, each of which examined different forms of yoga interventions and in which
the severity of the condition ranged from mild to severe. All trials reported positive
findings, but methodological details such as method of randomization, compliance and
attrition rates were missing. No adverse effects were reported with the exception of
fatigue and breathlessness in participants in one study. The Pilkington et al. summary
concludes: “Overall, the initial indications are of potentially beneficial effects of yoga
