Sudden cardiac death is one of the most frightening medical emergencies because it often happens without warning.
It occurs when the heart suddenly stops beating properly, causing blood flow to the brain and body to stop almost immediately. In many cases, death can happen within minutes if emergency treatment is not given quickly enough.
In younger adults, sudden cardiac death is often caused by inherited heart conditions or problems with the heart’s electrical system. In older adults, it is more commonly linked to blocked arteries and other forms of heart disease. Around the world, sudden cardiac death remains one of the leading causes of unexpected death.
Scientists have also known for many years that people with mental health conditions often face a higher risk of physical health problems, including heart disease. Studies have shown that people living with depression, anxiety, bipolar disorder, and other psychiatric illnesses tend to die earlier on average than the general population.
Researchers believe this may be caused by a combination of factors, including chronic stress, unhealthy lifestyle habits, poor sleep, smoking, alcohol use, and reduced access to healthcare.
At the same time, antidepressant medications have become extremely common. Millions of people worldwide take antidepressants to help manage depression and other mental health conditions. These medicines can greatly improve quality of life and, for many patients, may even save lives by reducing severe depression and suicide risk.
However, scientists still do not fully understand how long-term antidepressant use affects heart health. Some earlier studies suggested certain antidepressants may influence heart rhythm, blood pressure, or other cardiovascular functions. But the relationship between antidepressant use and sudden cardiac death has remained unclear.
Now, a new study presented at EHRA 2025, a major scientific meeting organized by the European Society of Cardiology, offers important new information.
Researchers from Denmark found that people who used antidepressants for many years were more likely to experience sudden cardiac death compared to people who had never used these medications.
The study was led by researchers including Dr. Jasmin Mujkanovic from Rigshospitalet in Copenhagen. The team analyzed medical records and death certificates from all Danish residents between the ages of 18 and 90 who died during the year 2010.
Denmark has detailed national healthcare records, which allowed the researchers to study a very large population. In total, they examined information from about 4.3 million people. Among these residents, nearly 46,000 people died during 2010, including more than 6,000 deaths classified as sudden cardiac death.
The researchers then investigated how many of these individuals had used antidepressants before their deaths. They defined antidepressant exposure as filling at least two antidepressant prescriptions within a single year at any point during the previous 12 years.
To better understand how treatment duration affected risk, the researchers divided antidepressant users into two groups. One group included people who had taken antidepressants for one to five years. The second group included people who had used the medications for six years or longer.
The findings showed a clear pattern. People who had taken antidepressants for one to five years had a 56% higher risk of sudden cardiac death compared to people who had never used antidepressants. For people who had used antidepressants for six years or more, the risk was more than twice as high.
The increased risk was especially noticeable among middle-aged adults. In people aged 30 to 39, those who had used antidepressants for one to five years were about three times more likely to die from sudden cardiac death compared to non-users. For those who had used antidepressants for six years or longer, the risk increased to five times higher.
Among adults aged 50 to 59, shorter-term antidepressant use doubled the risk, while longer-term use increased the risk fourfold.
In older adults, the differences between shorter and longer antidepressant use became smaller. For people aged 70 to 79, the risk remained elevated, but the gap between shorter and longer exposure was less dramatic. In people younger than 30 and older than 80, researchers did not find statistically significant differences between shorter and longer antidepressant use.
The study does not prove that antidepressants directly cause sudden cardiac death. Instead, it shows a strong association between long-term antidepressant use and higher risk.
Researchers say there may be several possible explanations. Some antidepressants may affect heart rhythm or other cardiovascular functions, especially when used over long periods. Certain antidepressants are already known to slightly increase the risk of abnormal heart rhythms in some patients.
At the same time, the underlying mental health conditions themselves may also contribute to the increased risk. People who require antidepressants for many years may have more severe or long-lasting depression or anxiety, which can affect physical health in many ways.
Depression has been linked to inflammation, chronic stress hormone changes, poor sleep, unhealthy eating habits, lack of exercise, smoking, alcohol use, and reduced medical care. All of these factors can increase the risk of heart disease over time.
The findings highlight the importance of carefully monitoring heart health in people taking antidepressants, especially those using the medications for many years. Researchers say doctors may need to pay closer attention to cardiovascular risk factors such as blood pressure, cholesterol levels, smoking, obesity, and physical activity in these patients.
The study also shows the need for more research to understand whether certain antidepressants may carry higher risks than others and whether some patients are more vulnerable to heart-related side effects.
Importantly, experts strongly warn that patients should not stop taking antidepressants without speaking to their doctor first. For many people, antidepressants are highly effective and essential treatments for serious mental health conditions. Suddenly stopping medication can cause withdrawal symptoms, worsening depression, and other dangerous complications.
Instead, the researchers hope the study will encourage better awareness, closer monitoring, and more personalized treatment approaches that protect both mental health and heart health.
The findings were presented at EHRA 2025 and add to growing research showing how closely mental and physical health are connected. Scientists say future studies may help doctors better balance the benefits and risks of antidepressant treatment while improving long-term health outcomes for patients.
If you care about health, please read studies about the benefits of low-dose lithium supplements, and what we know about egg intake and heart disease.
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