Exploring the links between depression and heart disease
The high frequency of depression in patients with heart disease can no longer remain a silent topic. Both depression and heart disease significantly contribute to the burden of disease. By the year 2020, it is estimated that depression will be the most common disease, second to heart disease. The co-occurrence of depression and heart disease has been reported in several studies, (e.g., Current Atherosclerosis Reports 2010). Depression has been found to be a significant predictor of mortality during the first six months in heart attack patients. Depression has also been found to increase the risk of coronary heart disease and to increase the risk of sudden death from a second heart attack.
The association between depression and heart disease among youth, however, has been researched less and, thus, is less known. This is very concerning given the high prevalence of psychiatric disorders, including depression, among youth and the overall negative impact that psychiatric disorders have on health. One recent long-term study published by the Archives of General Psychiatry in November 2011 looked at the association of depression and history of attempted suicide with mortality caused by heart disease among young adults in the U.S. The study, from 1988 to 1994, included 7,641 adults from 17 to 39 years of age. The study found that:
- Depression and history of attempted suicide were each associated with ischemic heart disease, IHD (reduced blood supply of the heart muscle) as well as with cardiovascular disease, CVD (dysfunction of the heart and blood vessels) mortality.
- Women with depression or a history of attempted suicide had a 3.2 times higher risk of dying from CVD and a 14.6 times higher risk of dying from IHD.
- Men with depression or a history of attempted suicide had a 2.4 times higher risk of dying from CVD and a 3.5 times higher risk of dying from IHD.
- Depression and a history of attempted suicide were significant predictors of premature CVD and IHD mortality among both men and women under the age of 40.
- Depression might increase the risk of IHD through stress-related physiological mechanisms such as increased cortisol or lower heart rate variability.
- Lifestyle factors might also be mechanisms through which depression is associated with IHD. However, the study showed a significant risk of depression and history of attempted suicide with IHD after controlling for health behaviours.
- The importance of stress reduction among young adults was emphasized.
Taken together from the studies, it is important to screen for depression among individuals, including youth, who have suffered from heart disease and to also do heart exams among those who suffer from depression. The early screening could help provide further opportunity for better diagnosis, treatment and survival.