A new study found that older adults who are consistently suffering from depression have twice the risk of suffering from a stroke compared to those who are not depressed.

Researchers at Harvard T.H. Chan School of Public Health looked at the data of 16,178 participants aged 50 and above between 1998 and 2010. The participants were asked about their depressive symptoms, history of stroke and their lifestyles.

The analysis showed that there were 1,192 cases of stroke during the study period. Those who reported severe symptoms of depression were twice as likely to have a stroke than those who had mild or moderate symptoms. The risk is considerably higher in women and those between the ages of 50 and 65.

The researchers believe that depression increased one's risk of stroke because of the physiological changes associated with it. For instance, when one is depressed, that person is more likely to drink and become less active, thus damaging one's overall health.

"This is the first study evaluating how changes in depressive symptoms predict changes in stroke risk," Paola Gilsanz, study lead author and a ‎Yerby Postdoctoral Research Fellow at Harvard Chan School, said in a news release. "If replicated, these findings suggest that clinicians should seek to identify and treat depressive symptoms as close to onset as possible, before harmful effects on stroke risk start to accumulate."

The symptoms of depression vary per person, but some of the common symptoms include feelings of sadness, hopelessness and disinterest. These symptoms can last for a week or months, and can interfere with work, social life and family life depending on the severity of the condition.

The study was published in the May 13 issue of the Journal of the American Heart Association.