Cardiovascular disease is the leading cause of death in industrialised nations, and this has been the case for well over a century. The physical risk factors associated with cardiovascular disease are now well established and for some time it has been hypothesised that psychological factors have a part to play in cardiovascular disease. In 2014, the American Heart Association officially listed depression as a cardiovascular disease (CVD) risk factor, despite this psychological factor have not yet been given the due attention for reduction of CVD.
Research is now showing that stress and depression, both independently and as a consequence as one another, can trigger a plethora of physiological sequalae leading to cardiovascular disease.
Firstly, when the body experiences psychological stress, for example relationship loss, work pressure etc, there are physiological changes in the nervous, hormonal and cardiovascular system that alter the stress on the heart. Stress for example can lead to a release in adrenaline and noradrenaline which raise heart rate and blood pressure, this increases pressure on blood vessel walls and on the heart muscle itself.
Secondly, stress and depressive thoughts can be viewed as a threat by the body which stimulates an immune response. As part of this immune response the body creates an inflammatory state, this alters chemical signalling and physiological processes that can accelerate cardiovascular disease.
A lesser known physiological consequence of the stress or depressive bodily response is the impact on the gut microbiome. It is now well established that the bacteria in the gut have a significant impact on our physical health, part of which is the cardiovascular system. More research is needed, but there are early indications that stressors can reduce the ability of the microbiome to flourish and therefore impact cardiovascular health.
Finally, stress and depression often lead to behaviour changes in an individual. Typically, these changes lead to less activity and more social isolation, both of which are associated with a more sedentary lifestyle and poor nutritional intake. Both of these changes in lifestyle are heavily correlated to diminished cardiovascular health.
In summary research is highlighting that physical parameters cannot account for all cardiovascular disease risk and now perhaps we need to place more value on the consequence of poor psychological health and its impact on physiological health.
Further reading: Larkin, K. T., & Chantler, P. D. (2020). Stress, depression, and cardiovascular disease. Cardiovascular Implications of Stress and Depression, 1–12.