Depression, Fatigue May Fuel Each Other
Having One May Dramatically Increase the Risk of Developing the Other
June 18, 2004 -- Depression and fatigue may feed off each other
in a vicious cycle that makes it hard to determine where one begins and the
other ends, according to a new study.
Researchers found people who are depressed are more than four
times as likely to develop unexplained fatigue, and those who suffer from
fatigue are nearly three times as likely to become depressed.
Although researchers have long suspected that depression and
unexplained fatigue are related, the nature of the relationship between the two
common conditions is unclear.
But the study, published in the current issue of
Psychosomatic Medicine, suggests that depression and fatigue may act as
independent risk factors for each other.
Depression and Fatigue Linked
In the study, researchers used information on more than 3,200
people who participated in the World Health Organization's study of
psychological problems and were monitored for one year.
Researchers found people who were depressed at the start of the
study were more than four times as likely to have an episode of unexplained
fatigue during that year.
In addition, those participants who were suffering from fatigue
at the start of the study were nearly three times as likely to develop
depression during the study.
Researchers say fatigue and the psychological disorder of
depression are not the same, and the two have different risk factors. However,
they may have some overlap.
"One can possibly understand how a fatigued person can
start feeling psychologically distressed because of his or her condition, but
the opposite is more difficult to explain," writes researcher Pertos
Skapinakis, MD, of the University of Ioannina in Greece, and colleagues.
Researchers say examining the role of physical activity may be
an important factor in helping to explain the association between the two
conditions in the future.
"Physical activity is known to have a protective effect on
depression," writes Skapinakis. "It has also been suggested that
physical deconditioning might be an important factor in the development of