Stress is an unavoidable condition of living. Exposure to chronic stressors is a threat to physical and mental health (Goldstein & McEwen, 2002; Wilson et al., 2020). The
relationship between stress and physical outcomes is reciprocal, cumulative, and epigenetic. Acute and chronic stress impose predictable effects on the cardiovascular system (Goldstein & McEwen, 2002; Wilson et al., 2020). Mental health conditions are associated with higher levels of distress as well as poorer chronic health conditions, including cardiovascular diseases, facilitating a tragic feedback cycle, whereby stress begets stress (Wilson et al., 2020). Further understanding of the brain-heart connection may help people develop more awareness of the importance of managing stress early and often.
The adaptation process refers to the stress reaction, which follows a predictable cascade events whereby the sympathetic division of the autonomic nervous system is enacted and the body readies for flight or fight (Goldstein & McEwen, 2002). Specifically, the sympathetic division causes the release of epinephrine, causing heart rate and respiration to increase, while cortisol (a major stress hormone) causes the release of free fatty-acids into the blood stream, and the pancreas releases glucose for fuel. All of these substances increase blood volume, thereby increasing blood pressure. During the stress-response, the major blood vessels supplying the heart and muscles dilate, increasing the workload of the heart. Additionally, the stress response incites inflammatory mechanisms (e.g., C-Reactive Protein; CRP and Interleukin 6; IL-6; Panagi et al., 2019). The cumulative effect of the stress response on the cardiovascular system includes damage to blood vessels, via high glucose and inflammatory substances, greater demand on the heart, depleted glutathione (an antioxidant used within cells for energy and repair) and increased oxidation (Goldstein & McEwen, 2002; Wilson et al., 2020).
In addition to the internal bodily response to stress, the physical exhaustion and emotional component of stress can induce unhealthy lifestyle behaviors, introducing another pathway for enhanced disease and decline (Cramer et al., 2020). When people are under stress, they tend to exercise less, eat foods higher in isolated sugars and fats, drink excess alcohol, and smoke cigarettes (Cramer et al., 2020). The long-term impact of unhealthy lifestyle behaviors is implicated in a number of diseases, but particularly cardiovascular health. Unhealthy lifestyle behaviors are more common among people who are also afflicted with a mental health condition, which may help to explain another reciprocal relationship between stress and mental and physical health (Cramer et al., 2020).
While evolutionarily adaptive in the short-term, chronic activation of the stress-response system is associated with greater propensity for disease and mortality (Shields & Slavich, 2017; Straub, 2017). Many mental health diagnoses are thought to be manifestations of chronic, unmitigated stress, including post traumatic stress disorder, major depression, substance use disorders, and anxiety disorders. The diathesis stress model of mental health suggests that mental health conditions result when an individual experiences a greater amount of distress than their body can adapt to. Exposure to repeated or chronic stressors upsets the homeostasis of the cardiovascular system and contributes to the allostatic load accumulated across the lifespan (Shields & Slavich, 2017). Mental health conditions could be thought of as facilitating a stress response that is on a constant, low simmer, contributing to further stress-responses and ongoing inflammation (Wilson et al., 2020).
With strong aversive emotions capable of fueling a persistent stress response, physical health may be further impacted, particularly cardiovascular conditions. Recent research has identified a strong connection with symptoms of depression, anxiety, and stress with poor cardiovascular health (Bahall et al., 2020; Wilson et al., 2020). This is quite notable as 78% of cardiovascular patients have been found to meet the diagnostic criteria for moderate and severe depression (Bahall et al., 2020). Cardiovascular patients exposed to the chronic stress and negative thinking patterns of depression are at greater risk of mortality and reduced quality of life (Bahall et al., 2020; Wilson et al., 2020). This connection between acute and chronic stressors in a cardiovascular and mental health context emphasizes the importance of proper mitigation of stress in the short term, perhaps through resilience training, and mental health conditions over the long-term, with pursuit of therapy with a skilled clinician before and especially after a cardiac diagnosis is made.
Bahall, M., Legall, G., & Khan, K. (2020). Quality of life among patients with cardiac disease: the impact of comorbid depression. Health and Quality of Life Outcomes, 18(1), 189. https://doi-org.ezproxy.coloradomesa.edu/10.1186/s12955-020-01433-w
Cramer, H., Lauche, R., Adams, J., Frawley, J., Broom, A., & Sibbritt, D. (2020). Is depression associated with unhealthy behaviors among middle-aged and older women with hypertension or heart disease? Women’s Health Issues, 30(1), 35–40. https://doi-org.ezproxy.coloradomesa.edu/10.1016/j.whi.2019.09.003
Goldstein, D. S., & McEwen, B. (2002). Allostasis, homeostats, and the nature of stress. Stress (Amsterdam, Netherlands), 5(1), 55–58. https://doi.org/10.1080/102538902900012345
Panagi, L., Poole, L., Hackett, R. A., & Steptoe, A. (2019). Happiness and Inflammatory Responses to Acute Stress in People With Type 2 Diabetes. Annals of behavioral medicine : a publication of the Society of Behavioral Medicine, 53(4), 309–320. https://doi.org/10.1093/abm/kay039
Shields, G. S., & Slavich, G. M. (2017). Lifetime stress exposure and health: A review of contemporary assessment methods and biological mechanisms. Social and Personality Psychology Compass, 11(8), 1–17. https://doi-org.ezproxy.coloradomesa.edu/10.1111/spc3.12335
Straub, R. H., & Cutolo, M. (2018). Psychoneuroimmunology-developments in stress research. Wiener medizinische Wochenschrift (1946), 168(3-4), 76–84. https://doi.org/10.1007/s10354-017-0574-2
Wilson, M. A., Liberzon, I., Lindsey, M. L., Lokshina, Y., Risbrough, V. B., Sah, R., Wood, S. K., Williamson, J. B., & Spinale, F. G. (2019). Common pathways and communication between the brain and heart: connecting post-traumatic stress disorder and heart failure. Stress (Amsterdam, Netherlands), 22(5), 530–547. https://doi.org/10.1080/10253890.2019.1621283