People who suffer from depression have a 45% increased risk of stroke and a 55% higher risk of having a fatal stroke, according to a new study.

In an analysis of almost 318,000 people and 8,478 stroke cases, researchers from the Harvard School of Public Health also found that depression is associated with a 25% higher risk for the less deadly ischemic strokes.

The relationship between depression and stroke is important to public health, researchers note, because stroke is the leading cause of disability. Lifestyle factors that might explain the link between depression and stroke include having poor health habits, such as drinking, smoking and not exercising. Depression also is correlated to conditions such as diabetes, high blood pressure and other inflammatory diseases.

The study was published in the Journal of the American Medical Association.