Depression Risk Lower In Heart Patients Who Take Statins

Depression Risk Lower In Heart Patients Who Take Statins

Heart disease patients who took statins, the drugs prescribed for lowering cholesterol, were significantly less likely to develop depression than counterparts who did not take the drugs, according to a new study led by Dr Mary Whooley, a professor of medicine at the University of California, San Francisco. The researchers write about their findings in an article published online in the Journal of Clinical Psychiatry on 21 February.

The researchers write in their background information that while their benefits for cardiovascular disease are well established, the effects of statins on depressive symptoms have not been examined.

In previous studies, Whooley found that heart disease patients who are depressed are less likely to exercise and take medication. This can increase their risk for cardiovascular events such as stroke and heart attack.

Statins lower the amount of "bad" cholesterol (low-density lipoprotein or LDL) in the blood, high levels of which can lead to fatty deposits in the arteries and thereby increase the risk of developing cardiovascular diseases such as coronary heart disease (angina and heart attack) and stroke.

They are one of the most commonly prescribed drugs in the world. In a press statement, Whooley describes them as "relatively safe, and generally well-tolerated."

Whooley and colleagues looked at data on 965 patients with coronary disease from 12 outpatient clinics in the San Francisco Bay Area. They noted which ones took statins, and which ones had depressive symptoms at baseline (2000-2002), and then followed them up for 6 years, during which time the patients filled in questionnaires every year.

From the yearly questionnaires (Patient Health Questionnaire or PHQ), the researchers assessed which patients developed depressive symptoms over the follow up.

The results showed that:

629 (65%) of the patients took statins.

At baseline, patients on statins had significantly lower mean PHQ depresssion scores than those who did not take the drugs.

Among the 776 patients without depressive symptoms at baseline, statin use was linked to a significant 48% reduced odds of developing depression during the follow-up period.

This link remained, but reduced to 38% when they adjusted for potential confounders such as smoking, exercise and cholesterol levels.

As the study went on, the researchers also noticed that the difference between the patients who were on statins and those who were not became more pronounced, with the statins users becoming less likely to develop depression and the non-users becoming more likely as the years went by.

They conclude:

"We found that statin use was associated with a decreased risk of subsequent depressive symptoms in patients with coronary heart disease."

However, they acknowledge the study did not set out to and therefore did not establish cause and effect, but the result warrants further investigation:

"Whether use of statins prevents depressive symptoms deserves further study," they urge.

Whooley said one explanation could be that "statins may have some kind of long-term protective effect against depression, perhaps by helping to prevent atherosclerosis in the brain, which can contribute to depressive symptoms".

Statins alter the endothelium, the inner lining of blood vessels. They stop the vessels getting stiff, so they can flex with the body's changing needs.

"The exact mechanism is not known, however, and requires further study," said Whooley.

Another explanation for their findings could be that patients who take statins just happen to be healthier overall than those who do not, and perhaps their analysis did not account for this, even though they adjusted for factors like smoking, physical activity and cholesterol levels.

Funds from the American Federation for Aging Research, the National Heart, Lung and Blood Institute, the Department of Veterans Affairs, the Robert Wood Johnson Foundation, the Ischemia Research and Education Foundation and the National Alliance for Research in Schizophrenia and Depression helped pay for the research.

Written by Catharine Paddock PhD
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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"Statin Use and Risk of Depression in Patients With Coronary Heart Disease: Longitudinal Data From the Heart and Soul Study"; Christian Otte, Shoujun Zhao, and Mary A. Whooley; Journal of Clinical Psychiatry posted online 21 February 2012; DOI: 10.4088/JCP.11m07038; Link to Abstract.
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