Depression and heart disease are considered comorbidities as the mortality rate for each disease is amplified by the existence of the other. In this particular case, diagnosis with one also amplifies the risk of developing the other.
At least one in three people experience depression after a heart attack or heart disease diagnosis [1,2]. People with depression also develop heart disease at a higher rate than the general population [2].
A meta-analysis of 28 studies found a 46% increase in the risk of developing cardiovascular disease in depressed patients compared to healthy subjects [3]. The Nord-Trøndelag Health Study (HUNT 2) also showed that the severity of depressive symptoms is associated with a proportionally higher risk of heart failure [3].
Why are Depression and Heart Disease linked?
Some connections between depression and heart disease are behavioral. For example, people who are anxious or depressed might use junk food, cigarettes, or alcohol to self-soothe. Or maybe depression and anxiety prevent them from exercising regularly. And then, of course, lack of exercise, processed foods, saturated fats, smoking, and heavy drinking are all associated with an increased risk for heart disease.
On the flip side, getting a heart disease diagnosis can be depressing. It may mean you cannot participate in some of the activities you enjoy, at least not right away. Illness and recovery can be isolating. Feeling suddenly helpless or dependent on others during recovery can also bring on negative emotions.
However, there may be some physiological connections too. Some biological processes either support or hinder both mental health and heart health, depending on their functionality.
Pathophysiology
One pathophysiological process shared by depression and heart disease is elevated blood platelet activation [3]. Blood platelets in normal circulation are non-adherent, but when activated, they adhere to other proteins in the blood to form clots, heal wounds, and maintain vascular integrity. Activation of platelets must be tightly regulated because dysregulated clot formation (thrombosis) causes blockage of blood vessels [4]. Depression and heart failure are both risk factors for dysregulation [3].
Depression and heart failure can both be characterized in part by dysregulated inflammatory pathways. Not only that but the inflammatory markers likely to be elevated in both depression and heart failure overlap. These shared markers include C-reactive protein, interleukin-6, interleukin-10, and tumor necrosis factor alpha [3].
The hypothalamic–pituitary–adrenal axis (how the body responds to stress) is also a possible shared mechanism between depression and heart disease [3].
Depression is associated with higher levels of stress hormones norepinephrine and epinephrine (adrenaline) [3]. The immune cells of heart failure patients with depressive symptoms show increased sensitivity to beta-adrenergic stimuli during stress or exercise [3]. Basal heart rate was higher in patients with higher depressive symptoms, and heart rate variability is typically impaired in patients with depression and/or heart disease [3].
Support for Depression and Heart Disease
Social support is so important in any disease state, be it mental, physical, or both. It can feel easier to withdraw when you are not feeling yourself, but spending time in the company of others is proven to promote recovery from both depression and heart disease [2].
Perhaps, spending time with others that are struggling or recovering similarly can provide the best support. For example, studies have shown that seeing the progress of other people recovering from a heart attack can significantly improve mood and confidence [2].
In any case, proper nutrition and a healthy lifestyle are key to recovery too. Regular exercise is essential for mood balance, but you should consult a doctor to come up with an exercise plan if you have been diagnosed with, or are recovering from heart disease.
If you’re here, you’re likely aware of the mood benefits methylfolate can provide. If you don’t know, read more about mood-supportive methylfolate by MethylPro here. There are several other nutrients that can make a big difference in supporting natural, healthy brain chemistry. We have some suggestions you can find here.
If you are looking for heart-supportive nutrition, check out this article from our sister company here.
References
- Zambrano, Juliana, et al. “Psychiatric and psychological interventions for depression in patients with heart disease: a scoping review.” Journal of the American Heart Association 9.22 (2020): e018686.
- Ziegelstein, Charlies. “Depression and Heart Disease”. Johns Hopkins Medicine. Accessed Jan 17, 2023. https://www.hopkinsmedicine.org/health/conditions-and-diseases/depression-and-heart-disease
- Sbolli, Marco, et al. “Depression and heart failure: the lonely comorbidity.” European journal of heart failure 22.11 (2020): 2007-2017.
- Li, Zhenyu, et al. “Signaling during platelet adhesion and activation.” Arteriosclerosis, thrombosis, and vascular biology 30.12 (2010): 2341-2349.