People who have had strokes are prone to depression, but a large, new study published on Monday said the psychological condition does not appear to raise the risk of stroke.
Instead, the study said high degrees of psychological distress - marked by anxiety and problems with emotional control - seemed to increase the risk, the British researchers reported in the journal Neurology.
"A diagnosis of major depressive disorder was not important for predicting future stroke," said Paul Surtees, a clinical psychologist at the University of Cambridge, who led the study.
Strokes, which occur when blood flow to the brain is blocked, can kill brain tissue and are one of the worldwide leading causes of death and permanent disability. Treatments include blood thinning drugs and attempts to lower cholesterol.
Previous studies have shown that strokes often lead to depression but the evidence has been mixed when it comes to whether depression causes strokes.
Surtees and his colleagues studied more than 20,000 people aged 41 to 80 over an eight-and-a-half-year period to see if they could find a link between depression and stroke.
During this time nearly 600 people in the study suffered a stroke, 28 percent of them fatal. After factoring for known risk factors such as smoking, high blood pressure, obesity and family history, they found no significant link between depression and stroke.
Instead, it seems that psychological distress plays a greater role. The most distressed people had a 40 percent higher stroke risk, Surtees said.
"The more distressed you were the greater the risk," Surtees said in a telephone interview.
The next step is to investigate exactly how psychological distress may lead to stroke, he added. The findings were similar for both men and women.
Distress may be a marker of other differences or indicate people having a tough time dealing with stressful situations, which may elevate their stroke risk, Surtees said.
