March 30, 2025

expert reaction to an unpublished conference abstract on association between use of antidepressant medication and risk of sudden cardiac death

An unpublished conference abstract presented at the European Heart Rhythm Association (EHRA) conference 2025 looks at the association between antidepressant medication use and and risk of sudden cardiac death. 

Dr Paul Keedwell, Consultant Psychiatrist and Fellow of the Royal College of Psychiatrists, said:

“This study suggests that the risk of sudden cardiac death might increase by 50% in individuals exposed to 1-5 years of antidepressant treatment and roughly double if exposed for 6 years or more, averaged across all age groups. The risks were higher above 40 years of age.

“The results should be treated with caution because the study was unable to separate the risks of antidepressant treatment from the risk of having depression per se. Depression is associated with high levels of heart disease, including sudden cardiac death (60% higher than non-depressed), life-threatening abnormal heart rhythm (50-90% increase in risk) and heart attack (roughly double the risk).

“People with depression die younger than those in the general population – up to 14 years earlier for males and 10 years earlier for females. Although suicide accounts for a lot of this increase in mortality, the most significant cause is poor physical health. This is thought to be because depressed individuals have an unhealthy lifestyle – they are more inactive and lack the motivation to cook healthy meals because of their illness.

“Therefore, the risk of early death associated with depressed people under treatment needs to be weighed against the risk of depressed people not under treatment. As far as absolute risk is concerned (the number of people actually affected), sudden cardiac death is a relatively rare event in the total population of depressed people, especially below 40, while the absolute risk of early death from suicide and other physical health problems is likely to be much higher: the increased risk of dying young from all causes in depression is up to double the risk in the general population, depending on the severity of the depression and the population studied.

“More research is needed to directly compare the life expectancy in treated and untreated depression, 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 than when it is treated. Therefore, people should not stop their antidepressant treatment based on this study.”

Prof Glyn Lewis, Professor of Epidemiological Psychiatry, University College London (UCL), said:

“There is a well established association between depression and an increased risk of cardiovascular disease. This association is not well understood but could be as a result of increased inflammation. This study does not provide good evidence that antidepressants themselves cause sudden death. It is likely that the association with sudden death is either due to depressive symptoms or to confounding by other factors.”

Dr Charles Pearman, Consultant Cardiologist and Electrophysiologist at Manchester University NHS Foundation Trust, and Honorary Research Fellow at The University of Manchester, said:

“This research, looking at the health records of 4.3 million Danish people, asked whether people were more likely to die suddenly and unexpectedly if they were taking an antidepressant.  They found that the risk of sudden death was low (1 in 1000 per year), but that people taking an antidepressant were twice as likely to die suddenly.   Previous studies have also shown that more powerful medicines called antipsychotics used to treat serious mental health problems are also associated with an increased risk of sudden death.

“There are several possible explanations for these findings.  It is well known that some antidepressants can increase the risk of dangerous abnormal heart rhythms in people with rare genetic heart conditions such as Long QT syndrome, a condition that can run in families.  Sometimes long QT syndrome is undetected before someone dies suddenly, and this may therefore have led to a small number of these sudden deaths. 

“Another possibility is that people who take antidepressants may not be directly responsible for these deaths, but instead antidepressant use may be a marker for having other health problems.  The most common cause of sudden death in people aged over 60 is from a heart attack caused by narrowings and blockages of the heart arteries.  These narrowings are more likely to occur in people who are overweight, who smoke, who do not exercise regularly, and who have high blood pressure or diabetes.  It is possible that people with depression who take antidepressants are more likely to have these other risk factors and health problems too.  The investigators tried to account for this possibility, but it is unclear which risk factors they considered.

“Overall, while there was an increased risk from taking antidepressants, the risk remains small.  People who are concerned about their risks should speak to their GP rather than stopping their medicines abruptly.  People who have a family history of sudden death, particularly at a young age, may want to be tested to see if they are at risk, and those with long QT syndrome should be aware of potential medicines that they need to avoid.  People with depression need to ensure that they look after other aspects of their health including taking regular exercise, avoiding smoking, and watching their weight.”

The abstract ‘The impact of length of antidepressant use on risk of sudden cardiac death’ was presented at European Heart Rhythm Association (EHRA) conference 2025. The embargo lifted at 16:30 UK time Sunday 30 March 2025.

Declared interests

Prof Glyn Lewis: I have funding from NIHR and Wellcome Trust. Travel and subsistence to ECNP 2023.

Dr Paul Keedwell: No conflicts.

For all other experts, no reply to our request for DOIs was received.