Heart Trouble Linked to Antidepressants in Controlled Twin Study

Contact: Amanda Jekowsky, ajekowsk@acc.org, 202-731-3069


Antidepressant Use, Not Depression Itself, Appears to Increase Thickening of Carotid Artery

New Orleans, LA – Middle-aged men taking antidepressants of any kind are more likely to have evidence of atherosclerosis as measured by carotid intima-media thickness (IMT) – a thickening of the inner lining of the blood vessels, which can increase their risk for heart attack and stroke, according to research presented today at the American College of Cardiology’s 60th Annual Scientific Session. ACC.11 is the premier cardiovascular medical meeting, bringing together cardiologists and cardiovascular specialists to further advances in cardiovascular medicine.

While previous studies have shown that people with depression have a heightened risk of heart disease, interestingly, neither depression nor Post Traumatic Stress Disorder (PTSD) was a significant predictor of IMT in this study. However, the study did show that subjects who take antidepressants and also report depressive symptoms appear to have higher IMT than those who take these medications but do not have depressive symptoms (p=0.049). The study – the first to assess vascular disease and antidepressant use, according to authors – measured IMT via B mode ultrasound in 513 male twins (mean age was 55 ± 3 years) from the Vietnam Era Twin Registry.

“There is a clear association between increased intima-media thickness and taking an antidepressant, and this trend is even stronger when we look at people who are on these medications and are more depressed,” said Amit Shah, M.D., cardiology fellow, Emory University, Atlanta, Georgia, and lead investigator of the study. “Because we didn’t see an association between depression itself and a thickening of the carotid artery, it strengthens the argument that it is more likely the antidepressants than the actual depression that could be behind the association.”

Antidepressant use was associated with a 37 micron (μm) increase in carotid IMT (roughly a 5 percent increase from the mean IMT value of 762 μm) in adjusted (p=0.006) analyses that controlled for heart disease risk factors (for example, age, diabetes, blood pressure, current or previous smoking, cholesterol, and body mass index), as well as depressive symptoms, history of major depression and heart disease, alcohol and coffee consumption, statin use, physical activity, education and employment status. Even when looking within 59 twin pairs where one brother is taking an antidepressant and the other is not, the brother taking the medication has a 41 μm thicker inner lining of the carotid artery (p=0.01, adjusted).

Authors explain that because each additional year of life is associated with a 10 μm increase in IMT, the brother taking the antidepressant is essentially four years “older” than the brother not taking the antidepressant in terms of the thickening of the carotid artery. In terms of the risk of heart attack or stroke, authors say previous studies have shown that each increase of 10 μm in IMT has been linked to a 1.8 percent increased risk.

Of the twins enrolled in the study, 16 percent were taking antidepressants, and of those, 60 percent were taking selective serotonin reuptake inhibitors (SSRIs). When comparing SSRIs to non-SSRIs, researchers found an increase in IMT regardless of the type of antidepressant taken.

Although the connection between antidepressants and heart health is not fully understood, these medications increase the level of certain chemical messengers, such as serotonin and norepinephrine, which are often low during states of depression. According to Shah, higher levels of such chemicals may potentially have an unhealthy effect on certain blood vessels by causing them to constrict or tighten. This may lead to decreases in blood flow to vital organs and higher blood pressure – a risk factor for atherosclerosis. Nonetheless, more research is needed to understand this and the relationship of such drug effects with depression itself.

Depression and PTSD were assessed with the Structured Clinical Interview for the Diagnosis of Psychiatry Disorders, and depressive symptoms were measured via Beck Depression Inventory. Medication regimens were verified by a clinician.

“Each twin had a detailed psychological evaluation and because this is a twin study, we had a very well controlled analysis comparing brothers who are anywhere from 50 to100 percent genetically similar and were raised in the same household,” Shah said.

Shah added that while this study suggests that antidepressants certainly play a role, further studies are needed to determine if antidepressants themselves increase IMT in the carotid arteries or if there are other factors related to antidepressant use that mediate this effect.

This study was funded by the National Institutes of Health.

Dr. Shah will be available to the media on Saturday, April 2 at 1:00 p.m. CDT in Room 338/339.

Dr. Shah will present the study “Association of Antidepressant Medications with Carotid Intima Media Thickness in Middle Aged Veteran Twins” on Tuesday, April 5, at 9:30 a.m. CDT in Hall F of the Ernest N. Morial Convention Center.

The American College of Cardiology (www.cardiosource.org) represents the majority of board certified cardiovascular care professionals through education, research, promotion, development and application of standards and guidelines – and to influence health care policy. ACC.11 is the largest cardiovascular meeting, bringing together cardiologists and cardiovascular specialists to share the newest discoveries in treatment and prevention, while helping the ACC achieve its mission to address and improve issues in cardiovascular medicine.


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