Getting "the blues" can, quite possibly, raise the risk of heart disease significantly... Brenda Penninx, a gerontologist at Wake Forest University, followed 2,900 patients, with and without heart disease, for four years to trace the effects of depression. At the end of the study, she found that patients with major depression were almost four times as likely to die of heart disease than those patients who did not suffer from depression, regardless of whether or not they had a history of cardiac problems. Even patients with mild depression experienced a fatality rate 50 percent higher than normal.
Depression often means stress, and stress triggers and outpouring of the hormone cortisol, which can cause your heart rate and blood pressure to increase. That response, happening over and over again, can be deadly. Hormones are not the only cause for the inner turmoil. Depressed people are usually less active and less likely to seek medical treatment. All of these can put someone at tremendous risk for life-threatening heart problems.
[The Institute of Nutrititional Science Journal, Vol. 5.8, July/August 2001]