In cases of mental depression, the plasma serotonin, melatonin and glutamate levels are increased along with the lowering of urinary - 5 - hydroxyindole acetic acid, plasma monoamine oxidase and cortisol levels following three and six months Practice of Kundalini Yoga. The pulse rate and blood pressure in these patients are also lowered after Kundalini Yoga practice. Thus, the practice of Kundalini Yoga helps to maintain a perfect homeostasis by bringing an equilibrium between the sympathetic and parasympathetic activities and it can be used as a non - medical measure in treating patients with mental depression.