New Delhi, March 31 : People with prolonged use of antidepressants may be at an increased risk of sudden cardiac death, which varies based on age and time of exposure, finds a study.

Sudden cardiac death refers to an unexpected death of a person, believed to be caused by a heart-related issue.

It occurs within one hour of the onset of symptoms in witnessed cases or within 24 hours of the person being last seen alive in unwitnessed cases.

The study, on 4.3 million residents in Denmark, showed that people exposed to antidepressants for 1 to 5 years had a 56 per cent higher risk of sudden cardiac death. On the other hand, those exposed to antidepressants for six or more years experienced a 2.2 times higher risk.

Among individuals aged 30-39 years, compared with the unexposed general population, those with one to five years of antidepressant exposure were around three times more likely to suffer sudden cardiac death. This risk increased to five times higher for those with six or more years of antidepressant exposure.

In individuals aged 50-59 years, those exposed to antidepressants for one to five years saw their risk of sudden cardiac death doubled. Among individuals exposed to antidepressants for six or more years, the risk of sudden cardiac death was four times higher.

'Exposure time to antidepressants was associated with a higher risk of sudden cardiac death, and linked to how long the person had been exposed to antidepressants,' said Dr Jasmin Mujkanovic from the Rigshospitalet Hjertecentret, Copenhagen, Denmark.

'Those exposed for six years, or more were at even more increased risk than those exposed for one to five years, when compared with people unexposed to antidepressants in the general population,' Mujkanovic added.

The causes in people under the age of 39 are often a thickening of the heart muscle or an electrical problem with the heart. In older people, it is more likely to be caused by a narrowing of the blood vessels that supply the heart, said the researchers, presenting the study at EHRA 2025, a scientific congress of the European Society of Cardiology.

Mujkanovic explained that the risk of sudden cardiac death may be caused by the potential adverse effects of the antidepressants as well as exposure time.

In addition, "the increase could be influenced by behavioural or lifestyle factors associated with depression, such as delayed healthcare seeking, and poor cardiovascular health,' she added, calling for further research.

/IANS