Does depression lead to stroke?

Psychological distress, but not depression, may increase the risk of stroke, according to a study published in the March 4, 2008, issue of Neurology, the medical journal of the American Academy of Neurology.

Previous studies have shown that stroke often leads to depression, but the evidence was mixed as to whether depression could lead to stroke.

“Stroke is among the leading causes of long-term disability and death worldwide,” said study author Paul Surtees, PhD, of the University of Cambridge in the United Kingdom. “Understanding the mechanisms by which overall emotional health may increase stroke risk may inform stroke prevention and help identify those at increased stroke risk.”

Researchers studied 20,627 people who had never suffered a stroke for an average of 8.5 years. Participants answered questions concerning their psychological distress, based on a scale measuring well-being, and their history of major depressive disorder. During the course of the study, 595 participants suffered a stroke and 28 percent of these strokes were fatal.

Researchers found that psychological distress was associated with an increased risk of stroke and that the risk of stroke increased the more distress the participants reported. This association remained the same regardless of cigarette smoking, systolic blood pressure, overall blood cholesterol, obesity, previous heart attack, diabetes, social class, education, high blood pressure treatment, family history of stroke and recent antidepressant medication use.

For every one standard deviation lower that participants scored on the mental well-being scale, their risk of stroke increased by 11 percent. The relationship was even more pronounced for those with fatal strokes.

The study found that the risk of stroke was not increased for people who had experienced an episode of major depression in the past year or for people who had experienced major depression at any point in their lifetime.