THURSDAY, Aug. 11, 2011 (HealthDay News) -- Depressed women may be at greater risk for stroke, new research suggests.
"We know that stroke can increase risk of depression, but depression itself may increase risk of future stroke," said study author An Pan, a research scientist at the Harvard School of Public Health in Boston.
"Depression is associated with hormonal changes in the body and affects chemicals in the brain, and we know that depression could be a marker for vascular disease," he said. "Depression is also associated with obesity, diabetes and hypertension, and people with depression are more likely to smoke and be physically inactive and not take their medication regularly."
Women with a history of depression were 29 percent more likely to have a stroke during six years of follow-up, and this finding held even when researchers controlled for other factors known to increase stroke risk. What's more, women who took antidepressants had a 39 percent increased risk of stroke.
The study was published online Aug. 11 in the journal Stroke.
The jury is out in terms of the role that antidepressants have in upping stroke risk, Pan said. "We don't know whether medications increase risk of stroke or if medicine is a marker for severity of depression."
Depressed women were more likely to be single, smoke and be less physically active than their non-depressed counterparts, the study showed. They were also slightly younger, had a higher body mass index and more coexisting conditions such as high blood pressure, heart disease and diabetes.
Pan and colleagues followed 80,574 women aged 54 to 79 who took part in the Nurses' Health Study from 2000 to 2006 and had no prior history of stroke. Depression was assessed via a standardized tool measuring symptoms, antidepressant prescriptions, and/or a diagnosis of depression from a doctor. Overall, 22 percent of women were depressed or had a history of depression when the study began, and there were 1,033 strokes during six years of follow-up. Specifically, 538 women had ischemic stroke, the most common form of stroke, which is caused by a blockage such as a blood clot, and 124 women had hemorrhagic or bleeding stroke, which occurs when a blood vessel in the brain bursts.
"If you have depression, see a doctor and get diagnosed," he said. "Treating your depression is very important to lower your future risk of cardiovascular disease, and if you have depression, you probably have some other lifestyle factors that you need to change."
Dr. Alan Manevitz, a psychiatrist at Lenox Hill Hospital in New York City, agreed. "Depression is associated with poor health behaviors including poor diet, lack of medication compliance and lack of exercise, all of which can increase stroke risk."
Depression can also cause biological changes that may increase risk for stroke, and may be a warning sign of stroke, he said. Many of the same lifestyle changes that help treat depression will also lower risk for stroke such as eating a healthy diet, engaging in regular physical activity, sleeping well and not smoking, he said.
Dr. Cathy Sila, director of the Stroke & Cerebrovascular Center at University Hospitals Case Medical Center in Cleveland, called the findings "provocative." The study only looked at women, but the findings likely apply to men as well, she added.
Sila said that more research is needed to better understand the relationship between stroke and depression. "There are important differences between depressed women and non-depressed women," she said. "Women who are depressed are more likely to have diabetes, hypertension and high cholesterol, be overweight and sedentary, all of which are known to increase risk for stroke."
Lifestyle changes can help lower stroke risk, but it is tough to make these changes when you are depressed, she said. "We need to understand how depression works against people making the type of changes they need to make," she said. "This study opens up a whole host of questions."
Learn more about depression at the U.S National Institute of Mental Health.