In research appearing in the January, 2007 issue of the journal Stroke, over 4,000 subjects who were part of the Framingham Heart Study were monitored over an eight-year period. The subjects had scores on a standard depression scale (called CES-D) averaging six. Eleven percent of the subjects scored 16 or higher—these patients were considered depressed.

A total of 144 strokes and 84 TIAs (a TIA is a “transient ischemic attack”—what is commonly called a mini-stroke) occurred in the group over the course of the study. The subjects under the age of 65 who scored higher than 16 on CES-D were four times more likely to have a stroke than someone in the same age group with low depression scores.