Tricyclic Antidepressants Linked to Increased Risk of Heart Disease
SOPHIA ANTIPOLIS, France -- December 1, 2010 -- Research that followed nearly 15,000 people in Scotland has shown that a class of older generation antidepressants are linked to an increased risk of cardiovascular disease (CVD).

The study showed that tricyclic anti-depressants were associated with a 35% increased risk of CVD, but that there was no increased risk with the newer antidepressants such as selective serotonin reuptake inhibitors (SSRIs). The study is published online today in the European Heart Journal.

The prospective study, which followed 14,784 men and women without a known history of CVD, is the first to look at the risks associated with the use of antidepressants in a large, representative sample of the general population. Until now, there have been uncertain and conflicting findings from earlier studies that have looked at the link between antidepressant use and the risk of CVD.

"Our study is the first to contain a representative sample of the whole community, including elderly and unemployed participants, men and women, etc," said Mark Hamer, MD, Department of Epidemiology and Public Health, University College London, London, United Kingdom. "Therefore, our results can be generalised better to the wider community. The majority of previous work in this area has focused on clinical cardiac patients, so studies in healthy participants are very important. Given that anti-depressants, such as SSRIs, 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 anti-depressants have increasing relevance to the general population."

Dr Hamer and colleagues used data from the Scottish Health Survey, which collects information from the general population every 3 to 5 years. They combined data from separate surveys in 1995, 1998, and 2003 in adults aged older than 35 years and linked them with records on hospital admissions and deaths, with follow-up until 2007. Anyone with a history of clinically confirmed CVD was excluded.

During the surveys, interviewers visited eligible households and asked participants a range of questions on demographics and lifestyle, such as smoking, alcohol intake and physical activity, and measured their height and weight. They assessed psychological distress using a questionnaire (the General Health Questionnaire) that enquires about symptoms of anxiety and depression in the last 4 weeks. In a separate visit, nurses collected information on medical history, including psychiatric hospital admissions, and medication, and took blood pressure readings.

During an average of 8 years follow-up there were 1,434 events related to CVD, of which 26.2% were fatal. Of the study participants, 2.2%, 2% and 0.7% reported taking tricyclic anti-depressants, SSRIs, or other antidepressants respectively. After adjusting for various confounding factors, including indicators of mental illness, the researchers found there was a 35% increased risk of CVD associated with tricyclic antidepressants. The use of SSRIs was not associated with any increased risk of CVD, nor did the researchers find any significant associations between antidepressant use and deaths from any cause.

"Our findings suggest that there is an association between the use of tricyclic anti-depressants and an increased risk of CVD that is not explained by existing mental illness," said Dr. Hamer. "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."

"Our findings suggest that clinicians should be cautious about prescribing anti-depressants and should also consider lifestyle advice, such as smoking cessation, exercise, and sensible alcohol intake."

SOURCE: European Society of Cardiology