A new study published in early March of this year shows that people with depression have a greater risk of developing cardiovascular disease (CVD), and that more women than men experience heart disease from depression.
Depression is a common mental health condition that causes symptoms of profound sadness and loneliness in afflicted people. People of any age and from any socioeconomic background may experience depression at some point in their lives. According to the World Health Organization (WHO), depression affects more than 264 million people worldwide.
The WHO also notes that cardiovascular diseases (CVDs) are the leading cause of death globally, taking an estimated 17.9 million lives each year. CVDs are a group of disorders of the heart and blood vessels and include coronary heart disease, cerebrovascular disease, rheumatic heart disease and other conditions. More than four out of five CVD deaths are due to heart attacks and strokes, and one third of these deaths occur prematurely in people under 70 years of age. Identifying those at highest risk of CVDs and ensuring they receive appropriate treatment can prevent premature deaths.
Researchers at Tokyo University in Japan who were behind the new study on the relationship between depression and cardiovascular outcomes analyzed data from the Japanese medical statistics and data services provider, JMDC Claims Database, between 2005 and 2022. They found 4,125,720 eligible participants, with a median age of 44 years, of whom over 42 percent were women.
The study found that although both men and women with depression have an increased risk of cardiovascular disease, women with depression had a 64 percent
increased risk rate for CVD, while men had a 39 percent increased risk. Previous studies have shown that cardiovascular disease affects women disproportionately, with 35 percent of women’s deaths annually attributed to CVD, which is more than the number of deaths from cancer, heart attacks and stroke.
Although the study did not examine in depth the reasons behind the gender-based difference between depression and CVD, other studies have offered potential reasons behind this association. One is that, as women progress to later stages of life (post-menopausal), the cardioprotective effects of their body’s estrogen begin to wane, and coupled with higher rates of inflammation and stress hormones from depression, leads to the disparity between men and women.
Many social factors can cause depression among females, including stress related to work, family responsibilities, and pressures to meet societal expectations. But because CVDs are associated more commonly with men, CVD in women remains understudied, under-diagnosed, and under-treated. For example, studies show that many people are unaware that heart disease is the #1 cause of death in women in many places.
Gaps in knowledge regarding women’s cardiovascular health care also impacts treatment provided to them. Much of the traditional teaching has emphasized that women may be ‘protected’ from heart disease, and for this reason, the actual risk of heart disease may be underestimated by women and health care providers.
As a result of this ‘double whammy’ of both women and health care providers underestimating the risk), heart disease may not receive enough attention in women compared to men.
Moreover, many women often seek medical attention for symptoms much later than men. Time taken to seek medical attention is important because the severity of a heart attack is directly related to the time from the onset of symptoms to the time the individual seeks medical attention. So if women seek medical attention later, they will be at increased risk.
Results from the new study add to the evidence in favor of addressing depression — through screening, referral, and treatment — to reduce the risk for heart disease in men and women. The study also highlights the importance of considering depression as a cardiovascular risk factor, similar to high blood pressure, diabetes, high cholesterol and smoking.
Studies examining the relationship between depression and heart disease have shown that it is ‘bidirectional’ — Depression is a risk factor for the development of heart disease, and heart disease is associated with an increased likelihood of developing or being diagnosed with depression. In addition, individuals with depression after a cardiovascular event are at greater risk of poor outcomes, including death, than individuals who have a cardiovascular event and who are not depressed.
Several reasons have been extended for the existence of this relationship between depression and CVD. Among others, individuals with depression find it more challenging to attend to many activities in life, including many of the activities that are important to prevent and/or treat heart disease, such as exercising, eating healthy or taking medications as prescribed.
The research team admitted that while their study sheds light on an important health concern, more studies on the effects of depression and heart health are needed, and other factors that could be involved would need to be taken into consideration, before conclusions on links between depression and CVD are made.
Experts also note that the study sample was based on medical claims information only, so subclinical symptoms of depression were not accounted for, and may be associated with a unique risk for depression. In addition, there was no data presented on which individuals received treatment for depression or other psychological conditions. Women-specific factors such as history of pregnancy, were also not accounted for.
