Harvard Health Letter

Harvard study links depression to stroke

Here's another reason to get depression treated as soon as possible: a Harvard study found that people with persistent symptoms of severe depression were twice as likely to suffer a stroke compared with people who have mild symptoms. The study appeared May 13, 2015, in the Journal of the American Heart Association. Researchers looked at the health information of more than 16,000 men and women ages 50 and older. The participants were interviewed every two years during a 12-year period and asked about many health issues, including depression symptoms. Researchers found that people who reported high depression symptoms at two consecutive interviews were more than twice as likely to have a first stroke than people with low depression symptoms. The stroke risk remained high even after depression symptoms went away.

The study showed only an association, and didn't prove that depression causes strokes. So why the link? Researchers speculate that depression—which is associated with high blood pressure, increased inflammation, and physical inactivity—may have a cumulative effect that causes damage to the blood vessels over time. Bottom line: Seek treatment if a case of the blues lasts more than two weeks, because it could be a sign of depression.