"Although the absolute risk of stroke is low in mid-aged women, depression does appear to have a large adverse effect on stroke risk in this age group," lead researcher Caroline Jackson, an epidemiologist in the School of Population Health at the University of Queensland in Australia, said in a statement. "Our findings, however, suggest that depression may be a stronger risk factor for stroke in mid-aged women than was previously thought." The study focused on women aged 47 to 52.
A stroke occurs when damage to an artery deprives the brain of oxygenated blood, causing brain cells to die and allowing toxic chemicals to build up. Approximately 795,000 people in the United States suffer a stroke each year (75 percent of stroke victims are 65 or older). The third leading cause of death in the U.S., strokes kill about 150,000 people annually.
Jackson and her colleague Gita Mishra, a professor of life course epidemiology at the University of Queensland, looked at data from 10,547 women aged 47 to 52 years, none of whom had a history of stroke. The women were all participants in the Australian Longitudinal Study on Women's Health, a research project that surveyed the women's mental and physical health every three years from 1998 to 2010.
About 24 percent of the women surveyed said that they suffered from depression and, during the course of the study 117 of them had a stroke for the first time.
After analyzing the data, Jackson and Mishra found that depressed women were 2.4 times more likely to have a stroke than women who did not say they were depressed. After eliminating other risk factors—including age, socioeconomic status, high blood pressure, obesity, heart disease, diabetes, and lifestyle choices like smoking, drinking, and exercising—middle-aged women with depression were still at higher risk for stroke than others in the group.
"Depression is a strong risk factor for stroke in mid-aged women, with the association partially explained by lifestyle and physiological factors," they concluded. Though the study did find a link between depression and stroke, it did not confirm that depression can cause a stroke. "Further studies of mid-aged and older women from the same population are needed to confirm whether depression is particularly important in younger women and to inform targeted intervention approaches," the researchers added.
Do you know how to spot the signs of a stroke? The American Stroke Association has a free iPhone or Android app that can help you determine whether someone is having a stroke. It suggests that people keep the acronym "F.A.S.T." in mind:
Face drooping. Ask the person to smile. Is the smile uneven? Does one side of the face droop or feel numb?
Arm weakness. Ask the person to raise both arms. Watch to see whether one drifts downward slowly. Also ask whether one or both arms feels weak, tingly, or numb.
Speech difficulty. Is the person's speech slurred or garbled? Is the person able to understand you easily? Can the person repeat a simple sentence accurately?
Time to call for help. If someone shows any of these symptoms, even if only temporarily, call 911 and take the person to the hospital immediately. Write down the time the first symptoms occurred, if possible.
May is National Stroke Awareness Month, and depression has long been thought to be a possible risk factor for strokes among elderly people. In 2011, after reviewing data from more than 80,000 women with an average age of 66 who took part in the Nurses Health Study, Harvard University researchers concluded that depression substantially increased the risk of stroke, though they also said that they weren't sure whether the increase was due to depression or to the medications used to treat it. Jackson's study, which was published this week in the journal Stroke, is the first to focus on middle-aged women.
The association between depression and stroke underscores "the need for adequate targeted prevention, detection and control of poor mental health among mid-aged women," Jackson said in a statement. "We need to carry out further research to identify the mechanism by which depression affects stroke risk, since this may have implications for development of future treatment of depression and stroke prevention strategies," she added.
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