This is the first large-scale study to link mental stress with blood-vessel blockages. The study does not prove that mental stress causes atherosclerosis. But the researchers hypothesize that, like cholesterol, mental stress may, over time, injure blood vessels and promote the buildup of arterial plaques. Further research is needed to test this theory.

In the study, researchers evaluated the responses of 901 Finnish men on a memory and cognition test designed to stimulate a state of mild mental stress. The men under age 55 who showed the most extreme blood-pressure response to the test had the thickest blockages from atherosclerosis in their carotid arteries. In fact, the blockages associated with mental stress in these men were equal to blockages linked to smoking and elevated cholesterol. This association was not significant in men older than 55, the study found.

The study?s lead author is Thomas Kamarck, PhD, associate professor of psychology at the University of Pittsburgh. His co-authors include Susan Everson, PhD, MPH; George Kaplan, PhD; Stephen Manuck, PhD; J. Richard Jennings, PhD; Riitta Salonen, MD, PhD; and Jukka Salonen, MD, PhD.