Harvard Study Finds Link Between Long-Term Depression and Stroke Risk

Adults with persistent depressive symptoms were twice as likely to suffer a stroke.

A new study from the Harvard School of Public Health reports some, well, depressing news about depression: Adults with long-term depressive symptoms may be twice as likely to suffer a stroke than other adults, even after those symptoms stop.

The study, led by Harvard research fellow Paola Gilsanz, is the first to examine how changes in depressive symptoms can foreshadow strokes. In an announcement from Harvard, Gilsanz notes that the findings highlight how important it is to be vigilant about depression, and address symptoms as early as possible:

“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.”

Gilsanz and her team interviewed more than 16,000 adults aged 50 and older every two years for more than a decade, asking them about their lifestyles, depressive symptoms, health problems, and stroke history. Subjects with depressive symptoms at two consecutive interviews were roughly twice as likely to suffer a stroke than those without symptoms, and risk remained higher for those individuals—especially women—even after symptoms went away. On the other hand, people who developed depression between interviews did not have an increased risk, suggesting that the ailment must be long-lasting to correspond to stroke danger.

Why, exactly, depression can lead to stroke is still unclear, though the researchers suggest that depression could lead to physical changes like vascular damage, which in turn lead to stroke. Lifestyle choices—like tendency to smoke and lack of exercise—that often go along with depression could also be risk factors.