“In a 2007 study in the Journal of Alternative and Complementary Medicine (Vol. 13, No. 4), researchers at Boston University School of Medicine and McLean Hospital used magnetic resonance imaging to compare levels of the neurotransmitter gamma-aminobutyric acid (GABA) before and after two types of activities: an hour of yoga and an hour of reading a book. The yoga group showed a 27 percent increase in GABA levels, which evidence suggests may counteract anxiety and other psychiatric disorders. GABA levels of the reading group remained unchanged.”[1]
“University of California, Los Angeles, psychologist David Shapiro, PhD, found that participants who practiced Iyengar yoga three times a week for eight weeks reported significant reductions in depression, anxiety and neurotic symptoms, as well as mood improvements at the end of each class (Evidence-based Complementary and Alternative Medicine, Vol. 4, No. 4). Many of the participants achieved remission and also showed physiological changes, such as heart rate variability, indicative of a greater capacity for emotional regulation, Shapiro says.”[2]
“A new report presented at the Anxiety and Depression Association of America (ADAA) Conference 2015 in April linked yoga to lowering levels of cortisol, the stress hormone, especially in women at risk for mental health problems.”[3]
In the May 2015 issue of Complementary Therapies in Clinical Practice, “researchers found that women experiencing postpartum depression saw a significant improvement in their anxiety, depression, and health-related quality of life after just eight week of yoga (twice a week) compared to their counterparts who did not practice yoga. In another unrelated study in the Indian Journal of Palliative Care, breast cancer patients who practiced 60 minutes of yoga daily over a 24-week period, which included surgery and radiotherapy or chemotherapy… reported a big drop in depressive symptoms compared to the non-yoga group.”[4]
“Consistent yoga practice improves depression and can lead to significant increases in serotonin levels coupled with decreases in the levels of monamine oxidase, an enzyme that breaks down neurotransmitters and cortisol.[5] … A number of studies demonstrate the potential beneficial effects of yoga interventions on depression, stress, and anxiety.[18,21,22]”[5]
[1] http://www.apa.org/monitor/2009/11/yoga.aspx
[2] ibid.
[3] http://www.sonima.com/yoga/health-benefits-of-yoga/
[4] ibid.
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3193654/