Antidepressants and the heart

A new study has raised concerns about the prolonged use of antidepressants, suggesting a significant link between long-term exposure and an elevated risk of sudden cardiac death (SCD). Conducted on a massive sample of 4.3 million residents in Denmark, the research sheds light on how both the duration of antidepressant use and age can impact heart health in potentially life-threatening ways.

Sudden cardiac death is defined as an unexpected, fatal event believed to stem from cardiac causes. It typically occurs within one hour of symptom onset in witnessed cases or within 24 hours of the person being last seen alive if the incident goes unwitnessed. While the condition is known for its unpredictability, this study offers insights into a preventable risk factor.

The research found that individuals using antidepressants for one to five years had a 56% higher risk of SCD compared to those with no history of antidepressant use. Alarmingly, this risk more than doubled—2.2 times higher—for individuals who had been exposed to antidepressants for six years or more.

Age-specific data painted an even more concerning picture. For people between the ages of 30 and 39, the risk of sudden cardiac death was nearly three times higher after one to five years of antidepressant use and escalated to five times higher with six or more years of use. In the 50 to 59-year age group, the risk doubled with short-term exposure and quadrupled with long-term use.

Dr. Jasmin Mujkanovic of Rigshospitalet Hjertecentret in Copenhagen, who presented the findings at EHRA 2025—a scientific congress of the European Society of Cardiology—highlighted the concerning trend. “Exposure time to antidepressants was associated with a higher risk of sudden cardiac death and was linked to how long the person had been exposed,” said Mujkanovic. “Those exposed for six years or more were at even greater risk compared to individuals unexposed to antidepressants in the general population.”

The mechanisms behind these findings appear to differ by age. In younger individuals, SCD is often attributed to a thickening of the heart muscle or electrical irregularities in the heart. In contrast, for older adults, the primary culprit tends to be coronary artery disease, which involves the narrowing of blood vessels supplying the heart.

Mujkanovic emphasized that the increased risk might not solely stem from the medications themselves. “The risk may be caused by the potential adverse effects of antidepressants as well as the duration of exposure,” she explained. Additionally, she pointed to behavioural and lifestyle factors commonly associated with depression—such as poor cardiovascular health and delayed access to medical care—as contributing elements.

While the study does not suggest halting antidepressant use outright, it does underline the importance of regular cardiovascular monitoring, especially in individuals undergoing long-term treatment. The findings also reinforce the need for further research to better understand the complex interplay between mental health treatments and heart health outcomes.

As millions worldwide rely on antidepressants for mental health management, this study urges clinicians and patients to consider cardiovascular risk in long-term treatment plans.