Table 3.

Studies on Yoga and Stress, Anxiety and Depression

Author/Year	Sample size	Participant characteristics	Location/ Setting of study	Study design	Intervention	Results	Conclusion
West et al., 2004 [66]	69	Healthy college students	Reed College, USA	Longitudinal cohort study	90-minute Hatha yoga session	Significant reduction in titers, negative affect, and cortisol	Hatha yoga reduces both cortisol and perceived stress level
Michalsen et al., 2005 [67]	24	24 self-referred female subjects who perceived themselves as emotionally distressed	Germany	Controlled prospective non-randomized study	3-month Iyengar yoga intervention among mental distressed women	Compared to the control groups significant reduction in perceived stress was observed	Yoga helps to improve perceived stress among distressed women
Janakiramaiah et al., 2000 [68]	45	Untreated melancholic depressive patients	Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore, India.	Randomized comparative trial	Sudarshan Kriya for 4 weeks among patients with melancholic depression	Significant reduction in depression score	Sudarshan Kriya demonstrated its antidepressant effects in depression
Smith et al., 2007 [65]	131	Subjects with mild to moderate levels of stress	Community in South Australia	A randomised comparative trial	10-week Hatha yoga intervention	Significant improvement in SF-36 scores was observed in yoga group	Hatha yoga intervention helps to improve stress, anxiety and health status compared to relaxation
Naveen et al., 2016 [69]	54	Adult outpatients with Major Depression	Out-patient services of NIMHANS, Bangalore, India	Prospective cohort study	3-month yoga intervention among patients with depression	Significant improvement in depression, BDNF, and serum cortisol was observed	3 month yoga intervention helped improve BDNF, cortisol, and depression in depressive patients
Streeter et al., 2012 [70]	34	Normal subjects with no prior yoga experience	Community in USA	Randomized comparative trial	60-minute yoga intervention	27% increase in GABA levels in yoga group	Yoga could help a treat disorders with low GABA levels like depression, anxiety
Shelov et al., 2009 [71]	46	Normal staff and students	Ferkauf Graduate School of Psychology (FGS) and the Albert Einstein College of Medicine (AECOM) in Bronx, New York	Randomized controlled trial	8-week yoga intervention	Elevated levels of mindfulness, per Freiburg Mindfulness Inventory	Yoga increases mindfulness and potentially prevents later development of negative emotional mood states

BDNF denotes brain-derived neurotrophic factor, GABA γ-aminobutyric-acid