Commonly used antidepressants may increase the risk of developing heart disease by more than a third, a study has found.
Old style anti-depressant drugs were linked with a 35 per cent increased risk of cardiovascular disease, the study found.
However, newer drugs were not associated with a rise which may signal that the older drugs may be causing the effect rather than the depression itself.
The research conducted by University College London involved nearly 15,000 people in Scotland and the results were published in the European Heart Journal.
Dr Mark Hamer, Senior Research Fellow in the Department of Epidemiology and Public Health at UCL (London, UK), said: “Our study is the first to contain a representative sample of the whole community, including elderly and unemployed participants, men and women, etc.
“Therefore, our results can be generalised better to the wider community. Given that antidepressants are now prescribed not only for depression, but for a wide range of conditions such as back pain, headache, anxiety and sleeping problems, the risks associated with antidepressants have increasing relevance to the general population.”
The study compared people on the old-style drugs called tricyclic antidepressants to those on the newer ones called selective serotonin reuptake inhibitors or SSRIs and those on none.
There were around 12m prescriptions dispensed in England for tricyclic antidepressants last year compared with more than 21m SSRIs.
Dr Hamer said: “Our findings suggest that there is an association between the use of tricyclic antidepressants and an increased risk of CVD that is not explained by existing mental illness. This suggests that there may be some characteristic of tricyclics that is raising the risk.
“Tricyclics are known to have a number of side effects; they are linked to increased blood pressure, weight gain and diabetes and these are all risk factors for CVD.”
He added: “It is important that patients who are already taking antidepressants should not cease taking their medication suddenly, but should consult their GPs if they are worried. There are two important points to be made. First, tricyclics are the older generation of antidepressant medicines and we found no excess risk with the newer drugs (SSRIs).
“Secondly, people taking the antidepressants are also more likely to smoke, be overweight, and do little or no physical activity – by giving up smoking, losing weight, and becoming more active a person can reduce their risk of CVD by two to threefold, which largely outweighs the risks of taking the medications in the first place. In addition, physical exercise and weight loss can improve symptoms of depression and anxiety.”
Amy Thompson, Senior Cardiac Nurse at the British Heart Foundation, said: “The results of this research should be interpreted with caution. The study wasn’t originally set up to assess the effect of antidepressants on heart disease risk, but it raised some questions.
“We know that findings like these can turn out to be red herrings, so before firm conclusions can be drawn there needs to be more research looking closely at the effects of these drugs on your heart.
“Anti-depressants are beneficial for many people and so it would be unwise for anyone taking them to stop based on the results of this study alone.
“We already know that people with depression are more likely to have unhealthy habits, like smoking, eating junk food and not getting enough physical activity. By addressing these lifestyle factors you can lower your risk of heart disease and help keep your heart healthy.”