TUESDAY, Nov. 30, 2004 (HealthDayNews) -- People who report symptoms of depression are more likely to die of stroke than those who say they're at peace with themselves, a new study suggests.
But it's possible the depression is a subtle signal of a major stroke in the making, the researchers added.
The two-decade-long study of nearly 13,000 men, whose average age was 46 at the start, found those who reported the most frequent symptoms of depression were twice as likely to die of a stroke as those who reported the fewest symptoms.
The findings appear in the Nov. 29 online issue of Stroke.
Some of those depressive symptoms may have been caused by "silent strokes," tiny blood vessel blockages or tears that can affect the brain, said study author Brooks B. Gump, an associate professor of psychology at the State University of New York at Oswego.
"That is a real possibility because silent strokes, by definition, are not detectable clinically but might well produce depression and predict fatal stroke later," Gump said.
By contrast, the study found a much smaller relationship between depression and the risk of death from heart attack or other cardiac conditions.
All the men were at higher-than-average risk of death from both stroke and heart disease because they had a number of risk factors. Those risk factors included high blood pressure, said Karen A. Matthews, a professor of psychiatry, psychology and epidemiology at the University of Pittsburgh, where the study was based.
The study took into account such risk factors, she said, adding, "We controlled for the standard things people look for."
The 20 percent of men who scored highest on a scale of depression were 21 percent more likely to die of heart disease and 15 percent more likely to die of any cause than those in the lowest 20 percent, the study found.
But the likelihood of dying from a stroke was much greater -- 103 percent for the 20 percent of men with the highest depression ratings, compared to those with the lowest ratings. In general, there was a steady increase in the incidence of death from stroke related to a man's self-assessment of depressive symptoms.
For example, men who were slightly depressed had more than a 20 percent risk of dying from a stroke than those reporting no depressive symptoms.
It's not possible to say for sure whether mini-strokes were at the root of the problem, Matthews said. "For that we would need a clinical trial, with periodic brain scans," she explained.
No matter the cause, the study "suggests that clinicians should ask their patients about depression," she said. "When people feel depressed they should be considered for treatment, pharmaceutical or behavioral."
To learn more about depression and its treatment, visit the National Institute of Mental Health.