When a person battles depression, there sometimes seems to be no way out of the dark hole. The last thing most people want to do is exercise for 30 minutes even though it can help make them feel better.

If a half hour of exercise seems like a marathon, take heart. A Duke University Medical Center study has found that a quick 10-minute walk may be enough to make clinically depressed people feel better.

The study, by health psychologist Kathleen Moore, involved a group of inactive depressed people age 50 and older. Before they began walking on a treadmill at maximum effort, the group took a mood test. Then they walked for eight minutes and completed the test again.

The participants showed immediate psychological changes, Moore says. Eighty-two percent said they were less tense, tired, angry, and confused after they walked. The same percentage reported feeling more vigorous.

"However, there was no control group, so we can't say for certain whether it was the exercise itself or some other factor," Moore says. The social support of the exercise staff may have made people feel better. Another study, which includes a control group, is now under way.