See this report in Life Extension Magazine.   "Stress hormones known as glucocorticoids are activated by both stress and depression. In turn, they cause imbalances in brain chemistry that interfere with mood and memory.23-26 The effect is biochemical. Glucocorticoids disrupt serotonin, dopamine, norepinephrine, and other brain chemicals.27,28 These “neurotransmitters” are the target of prescription antidepressants such as Prozac® and Wellbutrin®. And it has been shown that glucocorticoids can