Researchers at the Harvard School of Public Health and Brigham and Women's Hospital examined 28 studies involving more than 317,000 people aged 18 and over who were followed for time periods ranging from two to 29 years.
They found that participants with depression were 45 percent more likely to have a stroke and 55 percent more likely to die of stroke than those without the mood disorder.
The authors guess that depression inflames hormones in the nervous system, which could increase stroke risk.
Their findings also showed that people with depression are more likely to smoke, be unhealthy in their eating habits, and be overweight -- all risk factors for stroke. "We think that in the future, depression should be considered as a risk factor for stroke," study author An Pan, a research fellow in the department of nutrition at the Harvard School of Public Health, told Time.
"We still need more evidence to see whether such screening will be beneficial to patients, but I think our study provides convincing evidence to support further research."
"Stroke is a leading cause of death and permanent disability," Pan wrote in a statement accompanying the study. "Given the high prevalence and incidence of depression and stroke in the general population, the observed association between depression and stroke has clinical and public health importance."
