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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
A systematic review shows aerobic exercise improves clinically diagnosed major depression compared with antidepressants or treatment as usual. Previous reviews found conflicting evidence of benefit. The new review only included the trials thought to have the most applicable results.
This meant that trials recruiting people who might not have a clinical diagnosis of depression or through media adverts were not considered. Also, studies were only included if they featured aerobic exercise – walking, jogging or using cardiovascular gym equipment rather than other activities such as stretching.
Exercise is already recommended as a low-intensity psychological intervention in national guidance. Though the review only included 11 trials of 455 adults, the results are encouraging, especially as it included both inpatients and outpatients. It provides a potential alternative option for people to consider rather than, or in addition to antidepressant medication.
Why was this study needed?
Depression is a common disorder, affecting around 10% of adults in England in 2017–18, amounting to about 4.5 million people. Almost a quarter of a million new cases are diagnosed each year.
Exercise has long been recognised as beneficial for physical health, but its effects in supporting mental health are less clear. One systematic review suggested that exercise may reduce depressive symptoms in new mothers.
A 2013 Cochrane review of exercise in depression found 39 trials of exercise in 2,326 people with depression. Overall, exercise was beneficial for depression compared with no treatment or other control intervention. However, differences between the studies meant the results were not robust.
The new systematic review excluded studies with certain characteristics that may have affected the reliability of previous reviews. These included using media to recruit participants or different types of exercise.
What did this study do?
This systematic review and meta-analysis of 11 randomised controlled trials compared aerobic exercise to antidepressants or usual care in 455 adults with a clinical diagnosis of major depression. Only studies that recruited participants through inpatient or outpatient mental health services were included. Most were from Europe, with one UK study. Studies in people with depression who also had other chronic health conditions were excluded from the analysis.
Aerobic exercise varied from walking, jogging, running or swimming to using cardiovascular gym equipment such as step machines and stationary bicycles. On average, exercise was mainly supervised 45-minute sessions three times per week.
Of the 11 trials, seven were rated as high quality. About a third of people who were eligible for the trials chose not to participate.
What did it find?
- Aerobic exercise was associated with moderate to large reductions in depression scores: standardised mean difference (SMD) −0.79 (95% confidence interval [CI] −1.01 to −0.57). SMD of 0.8 and above means that the treatment had a moderate-to-large effect. Studies were similar enough for the analysis to be robust.
- The results were similar in sensitivity analyses that included only the trials rated as high quality (SMD −0.70, 95% CI− 0.94 to −0.45); considered the participants’ exercise preferences (SMD −0.84, 95% CI −1.17 to −0.51); or trials of four weeks or less (SMD −0.71, 95 CI −1.09 to −0.34).
- Similar findings were also seen in subgroup analyses that split the studies by their characteristics. These included severity of depression, whether exercise equipment was needed, whether exercise was performed by individuals or in groups, and whether it was conducted in hospital or not.
What does current guidance say on this issue?
NICE’s 2009 guideline on depression recommends regular physical exercise as part of advice on better sleep. A structured group physical activity programme is also a recommended low-intensity psychological intervention. Other low-intensity options are guided self-help using principles of cognitive behavioural therapy (CBT) or computerised CBT.
This guideline is being updated with publication expected in late 2019. Draft recommendations include structured exercise programmes specifically designed for people with depression.
What are the implications?
People with depression may reduce their participation in physical activities. This review adds to the evidence base showing that exercise has a role in treating depression.
The review found a large effect of exercise in depression even though only a few hundred people participated in the trials. Unlike much research on physical activity, these studies mainly featured supervised exercise sessions, so we know more about the actual levels of activity undertaken.
The careful selection of studies and the quality of included research could help mental health teams and others to promote with confidence the benefits of exercise for this patient population. This study lends support to guideline recommendations for exercise as a low-intensity intervention for people with depression.
Citation and Funding
Morres ID, Hatzigeorgiadis A, Stathi A et al. Aerobic exercise for adult patients with major depressive disorder in mental health services: a systematic review and meta‐analysis. Depress Anxiety. 2019;36(1):39-53.
No funding information was provided for this study.
Bibliography
Cooney GM, Dwan K, Greig CA et al. Exercise for depression. Cochrane Database Syst Rev. 2013;(9)CD004366.
NICE. Depression in adults: recognition and management. CG90. London: National Institute for Health and Care Excellence; 2009.
NICE Depression in adults: treatment and management. NICE guideline: short version. Draft for second consultation. London: National Institute for Health and Care Excellence; 2018.
Public Health England. Common mental health disorders: prevalence England. London: Public Health England; accessed January 2019.
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