“We found important and significant results,” said Andreas Heissel, an exercise scientist at the University of Potsdam in Germany, who led the study.
For people struggling with depression, he said, the results show that you don’t have to run marathons or train vigorously to benefit. “Something is better than nothing,” Heissel said.
The effects were robust enough that the study authors hope the finding will spur exercise as a standard prescribed therapy for depression.
This approach would represent a significant change. The American Psychological Association’s clinical practice guidelines, updated in 2019, recommend seven types of psychotherapy and several antidepressants for treating depression, but they don’t mention exercise. The World Health Organization promotes exercise for mental health as an adjunct to traditional treatments — not by itself.
But the authors of the study are confident. “We expect this review to lead to updated guidelines and recommendations for exercise as a first-line treatment option,” Heissel said.
Some depression experts are hesitant. “I think this exercise should be prescribed to anyone with depression,” said Murray B. Stein, professor and vice chair of clinical research in the department of psychiatry at the University of California, San Diego, who was not involved in the study. . “I still think the evidence is weak, however, for exercise to be considered a first-line treatment for depression.”
The research behind exercise and depression
Scientists and clinicians have known for some time that exercise protects us against the development of depression. In large-scale epidemiological studies, active men and women become depressed at much lower rates than sedentary people, even if they exercise only a few minutes a day or a few days a week.
But testing exercise as a treatment for existing depression is trickier. You have to study it like any drug, by recruiting people with the disease and randomly assigning them to the intervention – in this case, exercise – or a control group and carefully following this that is happening.
Because these experiments tend to be complicated and expensive, previous studies using exercise for depression have been small, typically involving only a few dozen people, making it difficult to draw firm conclusions on the question of whether physical exercise treats depression and to what extent.
In the study published in February in the British Journal of Sports Medicine, a global group of researchers brought together all the recent experiences using physical activity as therapy for depression. They ended up with data from 41 studies on 2,265 volunteers, representing the largest sample to date on this topic.
The exercise programs in the studies included walking, running, and weight training. Some were group lessons, some solo, some supervised, some not. But all featured people with depression getting up and moving more.
Exercise of any kind treats depression
Taken together, the effects were powerful. Overall, people with depression who exercised in any way improved their symptoms by nearly five points, using a widely accepted diagnostic scale, and by about 6.5 points using another. For both scales, an improvement of three or more points is considered clinically meaningful, the study authors write.
Concretely, these numbers suggest that for every two people with depression who start exercising, one should experience “a large-scale reduction in depressive symptoms,” Heissel said.
These statistics represent “somewhat better” results than those seen in recent studies of psychotherapy and drug treatment of depression, said Felipe Schuch, professor of exercise and mental health research at the University of Santa Maria in Brazil and lead author of the study.
In general, the effects were better if people exercised moderately, such as walking, although more vigorous workouts including running, cycling, and weight training were nearly as effective, and even light activities such as gardening alleviated the symptoms.
Overall, the study “shows that exercise is another effective, stand-alone treatment option” for depression, Heissel said.
The study did not examine how exercise might improve mental health. In previous research on depressed mice, as well as people, exercise increased levels in the brain and bloodstream of various biochemicals known to be involved in improving mood. It also often increased people’s self-efficacy, that is, the feeling that you are capable of more than you previously thought, a change usually associated with better mental health.
But the precise mechanisms by which body movements alter brain function to improve mood remain unclear, as do the differences in people’s responses. In each study included by the researchers, some people’s depression disappeared, while others’ symptoms remained stubbornly unchanged. (Similar disparities are also seen in almost all studies of psychotherapy and drug treatment.)
What is the right dose of exercise?
“To formulate exercise as a medical prescription, we still need more research to understand the optimal type, frequency, and amount of exercise for different people,” said Karmel Choi, clinical psychologist and assistant professor at the Center. for Precision Psychiatry from Harvard Medical. Massachusetts General Hospital and School. She studied exercise and depression, but did not participate in the new study.
“Depression is not one size fits all,” she said, “so treatment should always be tailored to the individual.”
UCSD’s Murray Stein agrees. “Exercise has so many health benefits that it should be prescribed for virtually anything that afflicts mankind,” he said.
But he’s still not convinced it should be a primary treatment for depression. “I would prescribe exercise as an adjunct” for patients with moderate to severe depression, he said, with psychotherapy or an antidepressant as the primary therapy.
Certainly more research is needed. “We don’t know enough about dose, intensity, and type of exercise,” Heissel said, or whether early activity-related improvements last. Future studies should delve into these questions and compare one-on-one exercise with psychotherapy and antidepressants, he said.
Perhaps most importantly, researchers and clinicians need to recognize how daunting exercise can be for a depressed person.
“A lot of people struggle to get active,” Heissel said. “So the first step is to try to figure out which exercise is most likely to be accepted and generate enjoyment.”
If you or someone you love is feeling depressed, Heissel said, talk to an exercise doctor about exercise, either as first therapy or in addition to other treatments. Experiment with different activities until you choose the one you like.
“The best exercise is the one that is actually done,” Heissel said, “and that means rewarding or enjoyable exercise.”
Do you have a fitness question? E-mail YourMove@washpost.com and we may answer your question in a future column.