Researchers from Harvard T.H. Chan School of Public Health analyzed medical records of more than 16,000 older adults who participated in the Health and Retirement Study between 1998 and 2010. As part of the study, participants were interviewed every two years about their depressive symptoms, history of stroke, and stroke risks factors.
Nearly 2,000 strokes among the participants were reported over the course of the study. The researchers found that individuals who displayed high levels of depressive symptoms during two consecutive interviews (over a four-year period) were more than twice as likely to experience a stroke during the subsequent two years compared with participants who had low depressive symptoms during two consecutive interviews. Even people who had depressive symptoms at the first interview but not the second had a 66 percent higher stroke risk, the study reports.
The researchers hypothesized that depression may influence stroke risk through physiological changes involving the accumulation of vascular damage over time.
“This is the first study evaluating how changes in depressive symptoms predict changes in stroke risk," lead author Paola Gilsanz, Sc.D, a postdoctoral research fellow at Harvard, said in a press 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.”
To read more about the relationship between depression and stroke, see the Psychiatric News article "Collaborative Care for Depression Can Reduce Risk for Heart Attacks, Strokes."