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What would you say about a remedy for depression that lifted your mood,
restored your energy, realigned your brain chemistry, improved your sense of
self-and cost nothing?
Then put on your walking shoes or find a workout class. Researchers are
finding that physical activity works at least as well against mild to
moderate depression as any other treatment. It may be an alternative to
current forms of treatment or a complement to them, even in severe cases.
Right now, mental health experts are carefully building a scientific dossier
on exercise as therapy for depression. Already, mounting evidence indicates
that regular activity combats depression on many fronts:
Animal studies show that exercise alters neurotransmitters such as
norepinephrine in the brain's frontal cortex and the hippocampus, both
involved in circuits of emotion; the changes are similar to those produced
by antidepressants.
It appears to stimulate the vagus nerve, improving function of the brain's
emotion-sensing network as well as of the heart. The vagus nerve is
increasingly recognized as an important pathway of depression.
By acting on neurohormones that govern the stress response, exercise seems
to improve the ability of the body to tolerate stress and to meet changing
demands. A dysregulated stress response, perhaps stemming from early
psychological trauma, is implicated as a cause of depression.
Exercise has definite cognitive effects; it changes people's perception of
themselves, providing a sense of personal mastery and positive self-regard.
It also reduces negative thinking.
Exercise keeps on working, making it especially promising for preventing
depression recurrences. People who continue to exercise have continuing
reductions in symptoms.
A push to document the effect of exercise in depression began after a report
by the U.S. Surgeon General linked physical inactivity to numerous modern
diseases. James Blumenthal, Ph.D., professor of medical psychology at Duke
University, was one of the first to step up to the plate, testing a
four-month program of aerobic exercise in people diagnosed with moderate to
severe depression.
The patients, sedentary men and women over 50, worked out for 30 minutes
three times a week in groups. Their response was compared with that of
similarly depressed patients who received either standard therapy with
Zoloft or drug and exercise combined.
Patients in all three groups experienced equally significant reductions in
depression symptoms, and remission rates were comparable-60% to 65%.
Surprisingly, combining two effective treatments, drug and exercise, added
no benefit.
In fact, the only difference among the groups was in speed of response. The
medication-alone group began improving within a few weeks; the exercisers
took a few weeks longer.
But the effects of exercise lasted longer. Six months after treatment ended,
fewer patients in the exercise group had relapsed into depression. Among the
patients no longer depressed, only 8% of the exercisers relapsed, compared
with over 30% in the medication group. "That was a big surprise," Dr.
Blumenthal confides.
Contrary to his own expectations, he found that exercise was beneficial
against severe depression. "Those with moderate to severe depression
responded as well as those with mild depression," he says.
Adherence rates to exercise programs turn out to be at least as good among
the depressed as among the general population, and they are comparable among
those getting medication and those exercising. Only 20% of patients dropped
out of the Duke exercise program sometime before the full 16 weeks.
There is a large pool of people looking for an alternative to current
therapies, says Andrea Dunn Ph.D., exercise psychologist at the Cooper
Institute for Aerobics in Dallas. In recruiting patients for a study, she
found "many people who knew they had symptoms of depression but didn't want
to take drugs." Besides, medication doesn't work in 30% to 35% of cases.
How exercise works against depression may be tied to its effect in improving
aerobic capacity of heart and lungs. Depression and heart disease are linked
through many channels. Even mild depression is a serious risk factor for the
development of cardiovascular disease. Depression increases the mortality of
pre-existing heart disease. People with depression have low heart-rate
variability, indicating diminished ability of the heart to respond to
stress. And exercise lowers mortality of heart patients.
Exercise undertaken to combat depression improves aerobic capacity and
cardiovascular fitness, and Dr. Blumenthal makes a strong case for aerobic
activities such as walking and jogging. "It was a surprise to us but we
found that the largest improvements in aerobic capacity correlated with the
greatest reductions in depression."
Still, there's more to the effect of exercise than fitness level. Several
studies show that resistance exercise, or weight training, is as effective
against depression as aerobic activity. At the very least, both likely
restore a sense of personal effectiveness. Both may also act on
neurotransmitters and on the vagus nerve.
So to help yourself or someone you love, together take a 30-minute walk
daily.