Two of the leading causes of morbidity and mortality worldwide are coronary heart disease (CHD) and mental illness. It appears that there may in fact, be a close link between the two, with some mental illnesses such as depression, considered a risk factor for heart disease and with the prevalence of heart disease being higher in those with mental illness. While it’s easy for us to think of our bodies as individual parts working together but separately, emerging research is revealing that this is not the case. From our guts and brains being in close cahoots to our hearts and minds heavily influencing one another, recent studies are finding the different systems within our bodies work together much more closely than we have ever realised.
What is heart disease?
Heart disease is a term encompassing a variety of medical conditions which can affect the heart. This can include blood vessel diseases such as coronary artery disease, heart rhythm disorders, birth defects and cardiovascular disease (which includes conditions such as coronary heart disease, heart failure, cardiomyopathy and peripheral vascular disease). Heart disease can lead to heart attacks, strokes and ultimately, death. When discussing the links between mental health and heart disease, it is coronary heart disease (CHD) which is being discussed. CHD generally presents itself with the narrowing of the arteries and a diminished supply of oxygen reaching the heart.
What is a mental health disorder?
Mental health disorders, or mental illnesses, can cover a vast array of disorders which affect your mood and the way you think. These include:
- Bipolar Disorder
- Post Traumatic Stress Disorder
With over 300 million people worldwide currently suffering from depression, and this number expecting to grow to become a leading cause of disability by 2030, the importance of understanding the causes and treatment of mental illness is becoming vital.
So how are heart disease and mental illness linked? In the case of our hearts and heads, it appears the link is bi-directional, with mental illness having the capacity to injure our hearts and our hearts having the potential to induce mental illness; this happens through a variety of biological, behavioral, psychological, and genetic mechanisms.
Stress on your body brought about by mental health conditions such as anxiety and depression can increase hormones like adrenaline and cortisol, subsequently increasing your blood pressure and heart rate. This can wreak havoc on your heart and increase your risk of heart disease.
Those experiencing heart issues, including being at a high risk of heart attacks and strokes, may have their physical abilities drastically diminished, finding their energy dwindling. This downturn in activity in a usually active person can lead to depression. Conversely, some heart disease risk factors such as smoking, physical inactivity, hypertension and obesity are more common in people with depression.
Our automatic nervous system (ANS) consists of two separate systems (sympathetic and parasympathetic) which work to control our heart rate, blood pressure and vasodilation; all processes vital to the running of a healthy heart. Patients with mental health disorders such as depression and anxiety have been found to exhibit higher levels of catecholamines, a hormone which can impact on your ANS, increasing your heart rate and blood pressure as well as decreasing blood flow to your heart.
Biochemicals associated with inflammation have been found to be produced in greater quantities in those with mental health disorders such as bipolar disorder, schizophrenia and depression. Inflammation is a contributing factor to the development, and progression of, heart disease.
The medication required to treat various mental health disorders can have an effect on the wellbeing of your heart. For example, the use of antipsychotic medication used to treat disorders such as schizophrenia, and (to a lesser extent) antidepressants and mood stabilizers, are thought to increase the risk of heart disease.
While research into the topic is in its infancy, the links between the heart and the head are becoming clearer. Identifying the link between the two is important to ensure patients experiencing one are screened for the other and receive comprehensive treatment for their condition.
 De Hert M, Detraux J, Vancampfort D. The intriguing relationship between coronary heart disease and mental disorders. Dialogues Clin Neurosci. 2018;20(1):31-40.