A number of medical studies on its preparatory practices have been published in international peer-reviewed journals. A range of mental and physical benefits are reported in these studies, including reduced levels of stress (reduced cortisol—the "stress" hormone), improved immune system, relief from anxiety and depression (mild, moderate, and severe), increased antioxidant protection, and enhanced brain function (increased mental focus, calmness, and recovery from stressful stimuli), among other findings.