Cortisol and antidepressant effects of yoga

Hypercortisolemia is well-known in depression and yoga has been demonstrated earlier to reduce the parameters of stress, including cortisol levels.

We aimed to find the role of yoga as an antidepressant as well as its action on lowering the serum cortisol levels.

An open-labeled study consisting of three groups (yoga alone, yoga along with antidepressant medication and antidepressant medication alone) was conducted at a tertiary care psychiatry hospital.

Out-patient depressives who were not suicidal were offered yoga as a possible antidepressant therapy. A validated yoga module was used as therapy taught over a month and to be practiced at home daily. Patients were free to choose the drugs if their psychiatrist advised. Patients (n=54) were rated on Hamilton Depression Rating Scale (HDRS) with serum cortisol measurements at baseline and after 3 months. In 54 patients, assessments and blood test results were both available. 19 each received yoga alone or with drugs and 16 received drugs only. Healthy comparison subjects (n=18) too underwent morning cortisol measurements once.

Serum cortisol was higher in depressives compared with controls. In the total sample, the cortisol level dropped significantly at the end of treatment. More patients in the yoga groups had a drop in cortisol levels as compared to drug-only group. In the yoga-only group, the cortisol drop correlated with the drop in HDRS score (antidepressant effect).

The findings support that yoga may act at the level of the hypothalamus by its 'anti-stress' effects (reducing the cortisol), to bring about relief in depression.