Depression – A Disease of the Heart

Depression is not just a disease of the mind. Depression hurts the heart, too.

It is well known that major depressive disorders increase the risk of cardiovascular morbidity and mortality. Dysfunctional autonomic control of the cardiovascular system is likely one cause of this relationship, but the true cause-and-effect of the association with depression is unknown. Poor recovery after exercise is indicative of dysfunctional autonomic control, and, recently, the first study examining the relationship between depression and post-exercise recovery was published.

The study, published in Psychophysiology, subjected nearly 900 patients to an exercise stress test. Heart rate, systolic blood pressure, and diastolic blood pressure were measured at rest, peak exercise, 1 minute post-exercise, and 5 minutes post-exercise. Patients with a major depressive disorder had slower heart rate recovery than patients without depression, indicating slow parasympathetic recovery from exercise and dysfunctional autonomic control in depressed individuals.

A similar, but smaller, study also revealed that symptoms of depression were negatively correlated to heart rate recovery after exercise. Further, an extensive analysis of physical fitness in individuals with depression indicated that peak oxygen consumption, maximum workload, and individual anaerobic threshold were significantly decreased in depressed patients, indicative of poor overall fitness. In the same study, heart rate recovery was significantly prolonged in depressed individuals, again pointing to autonomic dysfunction and an elevated cardiac risk profile.

Depression has long been associated with an increased risk of death in patients with cardiovascular disease, but the mechanism has not been clearly defined. Many clinicians believe it is the high levels of inactivity, obesity, anxiety, and insomnia that contribute to poor cardiovascular health. But, these studies reveal that the association between depression and heart health are not solely attributable to such external factors.

The benefits of activity in depression are not in question; increased physical fitness alleviates symptoms of depression, and improves overall health and well-being. Just how much and how hard people with depression should exercise is debatable, but exercise programs to decrease the specific cardiovascular risks in these individuals should be encouraged.

References

Boettger S, Wetzig F, Puta C, Donath L, Müller HJ, Gabriel HH, & Bär KJ (2009). Physical fitness and heart rate recovery are decreased in major depressive disorder. Psychosomatic medicine, 71 (5), 519-23 PMID: 19414614

Gordon JL, Ditto B, Lavoie KL, Pelletier R, Campbell TS, Arsenault A, & Bacon SL (2011). The effect of major depression on postexercise cardiovascular recovery. Psychophysiology, 48 (11), 1605-10 PMID: 21806634

Hughes JW, York KM, Li Q, Freedland KE, Carney RM, & Sheps DS (2008). Depressive symptoms predict heart rate recovery after exercise treadmill testing in patients with coronary artery disease: results from the Psychophysiological Investigation of Myocardial Ischemia study. Psychosomatic medicine, 70 (4), 456-60 PMID: 18434491

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