Combining the results of 17 studies on depression and stroke,researchers found that people who had depression at some point in their lives were about a third more likely to suffer a stroke than those who havent been depressed. The analysis seems very convincing, said Maria Glymour,a professor at the Harvard School of Public Health,who was not involved in the study. What is not understood,she added,is whether depression is somehow causing the increased risk of stroke,or whether the two diseases have the same underlying causes. A previous study by Glymour and her colleagues was included in the latest research,led by Dr Li-Qiang Qin at Soochow University in China. Qins group compiled data from 17 studies,totalling more than 200,000 participants,that looked at whether people with depression were more likely to suffer a stroke than people who did not have symptoms of the mood disorder. Each of the studies began with people who had not yet had a stroke,and followed them for anywhere from three to 29 years. Two studies reported that depression was tied to a lower risk of stroke,and another two found nearly no difference in risk between those with depression and those without. The other 13 studies showed an increased risk of stroke for people with depression,and when the team combined all 17 studies,they found that the risk of stroke was 34 percent higher among those with depression.
