Dec. 25, 2000 -- Claire Urmson began strength training several years ago to recover from an accident. To her surprise, the improvement she felt went far beyond her immediate physical problem. "I'm not somebody who loves exercise," says Urmson, 66. "But I really love the way it makes me feel."
Indeed, a recent Finnish study joins a growing body of research in suggesting that exercise can have strong psychological benefits. Scientists surveyed 663 people in Finland, ages 65 and older, in 1988 and again in 1996. Over time, the intensity of physical exercise (defined in three categories: doing necessary chores, walking regularly, and exercising strenuously, in order of increasing difficulty) decreased with age, and this decrease was associated with developing more symptoms of depression. The researchers therefore concluded that a reduction in exercise increased the risk of depression in older adults.
The study did have limitations. For instance, circumstances that impeded exercise could in and of themselves be depressing, the researchers said. But many experts believe that exercise has a direct impact on depression -- and not just in older people.
"The findings are the same in elderly people as in younger people: Exercise tends to lower depression" and anxiety, says Daniel Landers, PhD, regent's professor in the department of exercise science and physical education at Arizona State University.
Some scientists believe that exercise may increase the concentrations in the bloodstream (and therefore the brain) of the neurotransmitters serotonin and norepinephrine, as do certain antidepressant drugs. Indeed, in a recent study of clinically depressed 50- to 77-year-olds at Duke University Medical Center, researchers found that performing regular exercise compared favorably in reducing depression over a 16-week period both with taking the antidepressant Zoloft (a commonly prescribed serotonin reuptake inhibitor), and with the combination of taking the drug and exercising.
Six months after the Duke study ended, the researchers completed a second round of interviews with the subjects to find out how they were faring. Remarkably, the scientists found that the subjects who were in the exercise-only group were far less likely to relapse into a major depression than either the group who had been on medication, or those who had combined medication with exercise.
The researchers speculated that people who attributed their improved mental health to their own personal efforts may have felt more empowered -- and thus were less likely to relapse into depression than people who may have attributed their improvement to taking a pill.
Now Duke is undertaking a new study to further examine the issue. For instance, how much of the exercise-only group's benefit had to do with the "social support" of getting together with other people to exercise? The new study will include subjects who exercise at home, as well as others who exercise in group settings.
The Duke researchers also want to focus on a recently identified phenomenon called "vascular depression." They think damage to the vessels that supply blood to the brain may be to blame in up to one third of depression cases. Where depression is caused by such basic plumbing problems, pharmaceutical solutions may turn out to be less effective than exercises that help counteract cardiovascular disease, they believe.
Depression in older adults is of special concern because it can be mistaken for dementia or other age-related ailments rather than as a potentially treatable illness. And while it is not clear that old age alone increases the risk of depression, the physical ailments that afflict many people as they grow older can cause such a reaction. So can some of their medications.
Beth Ellis, 69, thinks the camaraderie of exercising at her local YMCA is part of what works for her. "There's something about exercising in a group that's also uplifting," she says. "It's sort of a community feeling."
What's more, she says, "My experience is that exercise is the most potent antidepressant you can imagine. I've been on Prozac from time to time during really bad periods, and it got me through." But each time she's on it, she eventually wants to stop her medication, and "exercise is one of the things that lets me handle it myself."
Exercising is no simple matter for Ellis. She has Charcot-Marie-Tooth disease, an incurable neurological disease that degrades sensation and motor control in the hands, feet, and limbs, leading to weakening of muscles through disuse. Ellis once was an avid runner, but as her disease progressed, running became impossible.
Losing her ability to run was a major blow for Ellis and likely triggered her depression. But now she goes to the YMCA for strength training, works on a cross-training machine, and does dance aerobics.
"So I'm still in the arena," says Ellis. "I am convinced that it really, really helps. If I'm unable to exercise for any reason, I really feel down in the dumps."
Scientists still are learning about why this is true. Is it exercise's effect on brain chemistry? Is it the boost to self-esteem? Is it the fellowship people gain when they exercise together? Or is it all of the above?
Urmson allows as how those questions are interesting. But the bottom line, she says, is simple: Exercise makes her feel better.
Has she slacked off since she first started working out after her accident? "Oh," she says with a laugh, "I'm afraid to stop."
David R. Dudley is based in Berkeley, Calif. His stories have appeared in The New Physician and The San Jose Mercury News.