Sudden cardiac death is one of the most frightening medical events because it happens quickly and often without warning.
It occurs when the heart suddenly stops beating effectively, which prevents blood from reaching the brain and other vital organs. Without immediate medical help, death can happen within minutes.
In many cases, sudden cardiac death occurs within an hour after the first symptoms appear. Some people may feel chest pain, dizziness, or shortness of breath just before it happens, but others experience no warning signs at all.
The causes of sudden cardiac death can vary depending on a person’s age. In younger people under the age of 40, the condition is often related to inherited problems with the heart’s structure or its electrical system. These problems can cause dangerous heart rhythms that suddenly stop the heart from pumping normally.
In older adults, the most common cause is coronary heart disease. This occurs when blood vessels that supply the heart become narrowed or blocked by fatty deposits. When blood flow to the heart is reduced or suddenly cut off, the heart may stop functioning properly.
For many years, researchers have noticed that people with mental health conditions tend to have a higher risk of early death. This includes a greater chance of dying from heart-related causes. Previous research has also shown that people with mental illness are about twice as likely to experience sudden cardiac death compared with the general population.
However, scientists have not fully understood whether antidepressant medications themselves might influence this risk.
New research presented at EHRA 2025, a major scientific meeting organized by the European Society of Cardiology, provides new information about this issue. The study was carried out in Denmark and examined how long-term use of antidepressant medications might be linked to sudden cardiac death.
The researchers analyzed national health records and death certificates for all Danish residents between the ages of 18 and 90 who died in the year 2010. Denmark has detailed medical records for its population, which makes it possible for scientists to study health patterns in large groups of people.
In total, the researchers looked at data from about 4.3 million residents. Among them, nearly 46,000 people died in 2010. More than 6,000 of those deaths were identified as sudden cardiac death.
The team also examined whether the people who died had a history of taking antidepressants. To define antidepressant use, the researchers counted people who had filled at least two prescriptions for antidepressant medications within a single year during the 12 years leading up to 2010.
Based on this information, the researchers divided people into different groups depending on how long they had used antidepressants. One group included people who had taken the medications for one to five years. Another group included people who had taken them for six years or longer.
Among the individuals who died from sudden cardiac death, around 2,000 had previously used antidepressants.
When the researchers compared the groups, they found that people who had used antidepressants for one to five years had a 56 percent higher risk of sudden cardiac death than those who had never taken the medications.
For people who had taken antidepressants for six years or more, the risk was even higher. Their likelihood of dying from sudden cardiac death was more than double compared with people who had never used antidepressants.
The increased risk was especially noticeable in middle-aged adults. For example, people between the ages of 30 and 39 who had used antidepressants for one to five years were three times more likely to experience sudden cardiac death than those who had never used the drugs.
Among people in the same age group who had used antidepressants for six years or longer, the risk increased even more. In this group, the chance of sudden cardiac death was about five times higher than in those who had never taken the medications.
Similar patterns were seen in people aged 50 to 59. In this group, the risk of sudden cardiac death doubled among people who had taken antidepressants for one to five years. For those who had used the medications for six years or longer, the risk was about four times higher.
Interestingly, the differences between short-term and long-term use became smaller in older age groups. Among people aged 70 to 79, the risk of sudden cardiac death was still higher among antidepressant users, but the gap between shorter and longer use was less pronounced.
In people younger than 30 and those older than 80, the researchers did not find a statistically significant difference between shorter and longer durations of antidepressant use.
According to Dr. Jasmin Mujkanovic from Copenhagen’s Rigshospitalet, who was involved in the research, the length of time a person uses antidepressants appears to matter. People who had used antidepressants for six years or more showed a greater increase in risk than those who had used them for shorter periods.
However, the researchers emphasized that this study does not prove that antidepressants directly cause sudden cardiac death.
There may be several possible explanations for the findings. Some antidepressants may affect the heart’s electrical activity or have other side effects that influence heart health. But it is also possible that the increased risk is related to the underlying mental health conditions themselves.
People who experience long-term depression or other mental illnesses may also have lifestyle factors that affect heart health. For example, they may be less physically active, have poorer diets, smoke more often, or be less likely to seek regular medical care.
These factors can gradually increase the risk of heart disease over time.
The study highlights the importance of monitoring heart health in people who use antidepressants, particularly those who take the medications for many years. Doctors may want to pay closer attention to cardiovascular risk factors such as blood pressure, cholesterol levels, and overall lifestyle habits.
At the same time, experts strongly warn that people should not stop taking antidepressant medications without medical advice. These medications are often essential for treating depression and other mental health conditions, and stopping them suddenly can cause serious problems.
More research will be needed to better understand why this link exists and whether certain types of antidepressants may carry different levels of risk.
If you care about heart disease, please read studies about a big cause of heart failure, and common blood test could advance heart failure treatment.
For more health information, please see recent studies about a new way to repair human heart, and results showing drinking coffee may help reduce heart failure risk.
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