Depressed? Do some exercise, says study

People who are suffering from depression may find relief by getting physically active, like walking or jogging, yoga, and strength training, a study suggests. More intense exercises also seem to provide greater benefits in reducing depression, while yoga and strength training are well tolerated versus other treatments.

“Exercise appeared equally effective for people with and without comorbidities and with different baseline levels of depression,” the researchers said.

“These forms of exercise could be considered alongside psychotherapy and antidepressants as core treatments for depression,” they added.

In this systematic review, the researchers performed article screening, coding, and risk of bias assessment independently and in duplicate. They also conducted Bayesian arm-based, multilevel network meta-analyses for the primary analyses. The confidence in network meta-analysis (CINeMA) online tool was then applied to grade the quality of the evidence for each arm.

Any randomized trial with exercise arms for participants meeting clinical cutoffs for major depression was identified and obtained using the databases of Cochrane Library, Medline, Embase, SPORTDiscus, and PsycINFO. A total of 218 unique studies with a total of 495 arms and 14,170 participants met the eligibility criteria for the meta-analysis. [BMJ 2024;384:e075847]

Compared with active controls such as usual care and placebo tablet, exercises provided moderate reductions in depression, particularly for walking or jogging (n=1,210; κ=51; Hedges’ g −0.62, 95 percent credible interval [CI], −0.80 to −0.45), yoga (n=1047; κ=33; g −0.55, 95 percent CI, −0.73 to −0.36), strength training (n=643; κ=22; g −0.49, 95 percent CI, −0.69 to −0.29), mixed aerobic exercises (n=1286; κ=51; g −0.43, 95 percent CI, −0.61 to −0.24), and tai chi or qigong (n=343; κ=12; g −0.42, 95 percent CI, −0.65 to −0.21).

The beneficial effects of these exercises increased with greater intensity. Additionally, yoga and strength training were found to be the most acceptable modalities.

Results, however, seemed susceptible to publication bias, but one study met the Cochrane criteria for low risk of bias. Based on the CINeMA tool, confidence was low for walking or jogging and very low for the other treatment modalities.

Mechanisms

“Our review did not uncover clear causal mechanisms, but the trends in the data are useful for generating hypotheses,” the researchers said.

“[W]e hypothesize that a combination of social interaction, mindfulness or experiential acceptance, increased self-efficacy, immersion in green spaces, neurobiological mechanisms, and acute positive affect combine to generate outcomes,” they added. [Cognit Ther Res 2014;38:600-611; Clin Psychol Rev 2022;94:102156; SSM Popul Health 2021;16:100934; Neurosci Biobehav Rev 2016;61:1-11; Health Psychol Rev 2021;15:540-573; Health Psychol Rev 2021;15:214-244]

Physical activity is recommended by the World Health Organization for everyone, including those with chronic conditions and disabilities. However, not everyone can adhere to this recommendation. [Br J Sports Med 2020;54:1451-1462]

“Many patients may have physical, psychological, or social barriers to participation,” said the researchers. “Still, some interventions with few costs, side effects, or pragmatic barriers, such as walking and jogging, are effective across people with different personal characteristics, severity of depression, and comorbidities.”

Additionally, health systems could provide exercise treatments as alternative or adjuvants to other established interventions, such as cognitive behaviour therapy and antidepressants, while reducing risks to physical health due to depression. [Am J Prev Med 2002;23:51-61]

“Therefore, effective exercise modalities could be considered alongside those interventions as core treatments for depression,” the researchers said.

“To mitigate expectancy effects, future studies could aim to blind participants and staff,” they noted.