April 2, 2025 from Medscape
Long-Term Antidepressant Use May Double Risk of Sudden Cardiac Death, Study Finds
A major new study out of Denmark is shedding light on the long-debated connection between antidepressant use and heart health. The research, presented at the European Heart Rhythm Association Congress 2025, found that individuals who used antidepressants for six years or more had more than double the risk of sudden cardiac death (SCD) compared to those who didn’t use the medications.
But researchers and external experts alike caution that the findings don’t mean antidepressants are inherently dangerous—or that patients should stop their treatment.
“I hope doctors don’t think they need to discontinue this treatment because it might pose a risk of sudden cardiac death,”
said study investigator Dr. Jasmin Mujkanovic, a PhD student at Copenhagen University Hospital.
What the Research Showed
The study examined death records and autopsy reports for the year 2010 across Denmark’s 4.3 million residents aged 18–90. Individuals were considered antidepressant users if they had filled at least two prescriptions for the medications in any given year from 1998–2009.
Key findings included:
- SCD was significantly higher among antidepressant users compared to non-users, particularly for those with 6+ years of use (HR, 2.17).
- For those with 1–5 years of use, the risk was also elevated (HR, 1.56).
- Risk was most pronounced in adults aged 40–69, but not significant in younger adults (18–39) or those over 80.
The study did not differentiate between types of antidepressants, nor did it separate data by sex. Mujkanovic noted that future research could explore those dimensions.
Why the Risk Might Be Higher
Researchers speculated that long-term antidepressant use may contribute to SCD risk through several biological pathways. Some antidepressants can prolong the QT interval, alter the heart’s electrical rhythm, or lead to significant weight gain and metabolic syndrome—both of which are known cardiac risk factors.
Still, Mujkanovic stressed that depression itself also increases cardiac risk. Effective treatment can improve lifestyle choices and reduce some heart-related threats.
“It’s like a chain reaction,”
he explained.
“Atherosclerosis is a known risk factor for ischemic heart disease, and ischemic heart disease increases the risk for myocardial infarction, which increases the risks for cardiac death.”
What the Experts Say
Commenting on the findings, UK-based psychiatrist Dr. Paul Keedwell urged caution in interpreting the results saying that it unable to separate the risks of antidepressants from the risk of having depression.
Depression is already known to:
- Increase risk of heart disease by 60%
- Raise likelihood of life-threatening arrhythmias by 50–90%
- Double the risk of heart attack
- Shorten lifespan by up to 14 years in men and 10 years in women
Keedwell emphasized that untreated depression is often more dangerous than the risks associated with medication.
“More research is needed… but as things stand, the weight of evidence supports the conclusion that the risk of early death is much higher when depression is left untreated.”
Cardiologist Dr. Charles Pearman added that antidepressants may not directly cause sudden cardiac death but may instead serve as a marker for other health conditions such as smoking, obesity, or diabetes.
What This Means for Patients
The overall risk of sudden cardiac death remains low—even among long-term antidepressant users. But this study adds to the growing body of evidence that mental health and physical health are deeply intertwined.
For workplace leaders and HR professionals, the findings are a reminder to support employee mental health without stigma or shortcuts. Helping workers manage depression—through access to therapy, medication, or other forms of care—can lead to better overall health outcomes and reduce the burden of chronic illness.
And for individuals managing depression, the takeaway is clear: do not stop antidepressant treatment without speaking to a doctor. As Dr. Pearman noted,
“People who are concerned about their risks should speak to their GP rather than stopping their medicines abruptly.”
Long-term antidepressant use may be linked to an increased risk of sudden cardiac death—but so is untreated depression. The goal should not be to eliminate treatment, but to ensure it’s part of a comprehensive, monitored care plan.
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