Exercise for depression
Editorial Group: Cochrane Depression, Anxiety and Neurosis Group
Published Online: 12 SEP 2013
Assessed as up-to-date: 13 JUL 2012
Copyright © 2013 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
How to Cite
Cooney GM, Dwan K, Greig CA, Lawlor DA, Rimer J, Waugh FR, McMurdo M, Mead GE. Exercise for depression. Cochrane Database of Systematic Reviews 2013, Issue 9. Art. No.: CD004366. DOI: 10.1002/14651858.CD004366.pub6.
- Publication Status: New search for studies and content updated (no change to conclusions)
- Published Online: 12 SEP 2013
Depression is a common and important cause of morbidity and mortality worldwide. Depression is commonly treated with antidepressants and/or psychological therapy, but some people may prefer alternative approaches such as exercise. There are a number of theoretical reasons why exercise may improve depression. This is an update of an earlier review first published in 2009.
To determine the effectiveness of exercise in the treatment of depression in adults compared with no treatment or a comparator intervention.
We searched the Cochrane Depression, Anxiety and Neurosis Review Group’s Controlled Trials Register (CCDANCTR) to 13 July 2012. This register includes relevant randomised controlled trials from the following bibliographic databases: The Cochrane Library (all years); MEDLINE (1950 to date); EMBASE (1974 to date) and PsycINFO (1967 to date). We also searched www.controlled-trials.com, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform. No date or language restrictions were applied to the search.
We conducted an additional search of the CCDANCTR up to 1st March 2013 and any potentially eligible trials not already included are listed as 'awaiting classification.'
Randomised controlled trials in which exercise (defined according to American College of Sports Medicine criteria) was compared to standard treatment, no treatment or a placebo treatment, pharmacological treatment, psychological treatment or other active treatment in adults (aged 18 and over) with depression, as defined by trial authors. We included cluster trials and those that randomised individuals. We excluded trials of postnatal depression.
Data collection and analysis
Two review authors extracted data on primary and secondary outcomes at the end of the trial and end of follow-up (if available). We calculated effect sizes for each trial using Hedges' g method and a standardised mean difference (SMD) for the overall pooled effect, using a random-effects model risk ratio for dichotomous data. Where trials used a number of different tools to assess depression, we included the main outcome measure only in the meta-analysis. Where trials provided several 'doses' of exercise, we used data from the biggest 'dose' of exercise, and performed sensitivity analyses using the lower 'dose'. We performed subgroup analyses to explore the influence of method of diagnosis of depression (diagnostic interview or cut-off point on scale), intensity of exercise and the number of sessions of exercise on effect sizes. Two authors performed the 'Risk of bias' assessments. Our sensitivity analyses explored the influence of study quality on outcome.
Thirty-nine trials (2326 participants) fulfilled our inclusion criteria, of which 37 provided data for meta-analyses. There were multiple sources of bias in many of the trials; randomisation was adequately concealed in 14 studies, 15 used intention-to-treat analyses and 12 used blinded outcome assessors.
For the 35 trials (1356 participants) comparing exercise with no treatment or a control intervention, the pooled SMD for the primary outcome of depression at the end of treatment was -0.62 (95% confidence interval (CI) -0.81 to -0.42), indicating a moderate clinical effect. There was moderate heterogeneity (I² = 63%).
When we included only the six trials (464 participants) with adequate allocation concealment, intention-to-treat analysis and blinded outcome assessment, the pooled SMD for this outcome was not statistically significant (-0.18, 95% CI -0.47 to 0.11). Pooled data from the eight trials (377 participants) providing long-term follow-up data on mood found a small effect in favour of exercise (SMD -0.33, 95% CI -0.63 to -0.03).
Twenty-nine trials reported acceptability of treatment, three trials reported quality of life, none reported cost, and six reported adverse events.
For acceptability of treatment (assessed by number of drop-outs during the intervention), the risk ratio was 1.00 (95% CI 0.97 to 1.04).
Seven trials compared exercise with psychological therapy (189 participants), and found no significant difference (SMD -0.03, 95% CI -0.32 to 0.26). Four trials (n = 300) compared exercise with pharmacological treatment and found no significant difference (SMD -0.11, -0.34, 0.12). One trial (n = 18) reported that exercise was more effective than bright light therapy (MD -6.40, 95% CI -10.20 to -2.60).
For each trial that was included, two authors independently assessed for sources of bias in accordance with the Cochrane Collaboration 'Risk of bias' tool. In exercise trials, there are inherent difficulties in blinding both those receiving the intervention and those delivering the intervention. Many trials used participant self-report rating scales as a method for post-intervention analysis, which also has the potential to bias findings.
Exercise is moderately more effective than a control intervention for reducing symptoms of depression, but analysis of methodologically robust trials only shows a smaller effect in favour of exercise. When compared to psychological or pharmacological therapies, exercise appears to be no more effective, though this conclusion is based on a few small trials.
Plain language summary
Exercise for depression
Why is this review important?
Depression is a common and disabling illness, affecting over 100 million people worldwide. Depression can have a significant impact on people’s physical health, as well as reducing their quality of life. Research has shown that both pharmacological and psychological therapies can be effective in treating depression. However, many people prefer to try alternative treatments. Some NHS guidelines suggest that exercise could be used as a different treatment choice. However, it is not clear if research actually shows that exercise is an effective treatment for depression.
Who may be interested in this review?
Patients and families affected by depression.
Mental health policy makers.
Professionals working in mental health services.
What questions does this review aim to answer?
This review is an update of a previous Cochrane review from 2010 which suggested that exercise can reduce symptoms of depression, but the effect was small and did not seem to last after participants stopped exercising.
We wanted to find out if more trials of the effect of exercise as a treatment for depression have been conducted since our last review that allow us to answer the following questions:
Is exercise more effective than no therapy for reducing symptoms of depression?
Is exercise more effective than antidepressant medication for reducing symptoms of depression?
Is exercise more effective than psychological therapies or other non-medical treatments for depression?
How acceptable to patients is exercise as a treatment for depression?
Which studies were included in the review?
We used search databases to find all high-quality randomised controlled trials of how effective exercise is for treating depression in adults over 18 years of age. We searched for studies published up until March 2013. We also searched for ongoing studies to March 2013. All studies had to include adults with a diagnosis of depression, and the physical activity carried out had to fit criteria to ensure that it met with a definition of ‘exercise’.
We included 39 studies with a total of 2326 participants in the review. The reviewers noted that the quality of some of the studies was low, which limits confidence in the findings. When only high-quality trials were included, exercise had only a small effect on mood that was not statistically significant.
What does the evidence from the review tell us?
Exercise is moderately more effective than no therapy for reducing symptoms of depression.
Exercise is no more effective than antidepressants for reducing symptoms of depression, although this conclusion is based on a small number of studies.
Exercise is no more effective than psychological therapies for reducing symptoms of depression, although this conclusion is based on small number of studies.
The reviewers also note that when only high-quality studies were included, the difference between exercise and no therapy is less conclusive.
Attendance rates for exercise treatments ranged from 50% to 100%.
The evidence about whether exercise for depression improves quality of life is inconclusive.
What should happen next?
The reviewers recommend that future research should look in more detail at what types of exercise could most benefit people with depression, and the number and duration of sessions which are of most benefit. Further larger trials are needed to find out whether exercise is as effective as antidepressants or psychological treatments.
Plain language summary
Tjelovježba za ublažavanje depresije
Tjelovježba za ublažavanje depresije
Zašto je važan ovaj sustavni pregled?
Depresija je česta bolest, koja pogađa više od 100 milijuna ljudi širom svijeta. Depresija može imati značajan utjecaj na zdravlje i smanjiti kvalitetu života. Istraživanja pokazuju da i lijekovi i psihološke terapije mogu učinkovito liječiti depresiju. Međutim, mnogim je ljudima draže pokušati alternativne mogućnosti liječenja. Neke smjernice pokazuju da bi se tjelovježba mogla koristiti kao jedna od terapija izbora. Međutim, iz rezultata nije potpuno jasno u kojoj je mjeri tjelovježba učinkovita za ublažavanje depresije.
Koga bi mogao zanimati ovaj sustavni pregled?
Pacijente i obitelji pogođene depresijom
Liječnike opće prakse
Specijaliste koji se bave mentalnim zdravljem
Osobe koje odlučuju o politikama vezanima za mentalno zdravlje
Na koja pitanja odgovara ovaj sustavni pregled?
Ovaj sustavni pregled je obnovljena verzija prethodnog Cochrane sustavnog pregleda, koji je objavljen 2010. i u kojem je utvrđeno da tjelovježba može ublažiti simptome depresije, ali je učinak bio malen i činilo se da ne traje nakon prestanka vježbanja.
Stoga su autori htjeli istražiti da li su u međuvremenu napravljena nova klinička istraživanja koja bi nam omogućila odgovor na sljedeća pitanja:
Je li tjelovježba učinkovitija od nikakvog liječenja za ublažavanje simptoma depresije?
Je li tjelovježba učinkovitija od lijekova protiv depresije (antidepresiva) za ublažavanje simptoma depresije?
Je li tjelovježba učinkovitija od psiholoških terapija ili ne-medicinskih terapija za depresiju?
Koliko je tjelovježba pacijentima prihvatljiva kao oblik liječenja depresije?
Koja su istraživanja uključena u ovaj sustavni pregled?
Autori su pretražili medicinske baze podataka kako bi pronašli sva visoko-kvalitetna randomizirana kontrolirana istraživanja koja odgovaraju na pitanje koliko je učinkovita tjelovježba za liječenje depresije u odraslih osoba starijih od 18 godina. Pretraživanjem literature autori su tragali za istraživanjima objavljenim do ožujka 2013. godine. Također su tražili studije koje su bile u tijeku do ožujka 2013. Sva istraživanja su morala uključiti odrasle osobe s dijagnozom depresije, a fizička aktivnost kojom su se bavili morala je zadovoljiti određene kriterije kako bi mogla odgovarati definiciji „tjelovježbe“.
U sustavni pregled je uključeno 39 kliničkih istraživanja s ukupno 2326 ispitanika. Autori sustavnog pregleda naglašavaju kako su neke od uključenih studija bile loše kvalitete, što ograničava pouzdanost rezultata. Kad su u analizu uključena samo visoko-kvalitetna istraživanja, tjelovježba je imala samo malen učinak na raspoloženje, koji nije bio statistički značajan.
Što nam govore dokazi iz ovog sustavnog pregleda?
-Tjelovježba je umjereno učinkovitija nego nikakva terapija za ublažavanje simptoma depresije.
-Tjelovježba nije učinkovitija od antidepresiva za ublažavanje simptoma depresije, iako se ovaj zaključak temelji na malom broju istraživanja.
-Tjelovježba nije učinkovitija od psiholoških terapija za ublažavanje simptoma depresije, iako se ovaj zaključak temelji na malom broju istraživanja.
-Autori sustavnog pregleda navode da je razlika između tjelovježbe i nikakve terapija bila manje uvjerljiva kad su analizirali samo visoko-kvalitetne studije.
-Ovisno o istraživanju, od 50 do 100% pacijenata pridržavalo se režima tjelovježbe.
-Dokazi o tome da tjelovježba depresivnim osobama može popraviti kvalitetu života nisu jasni.
Što bi se trebalo zbiti dalje?
Autori sustavnog pregleda preporučuju da bi buduća istraživanja trebala detaljnije istražiti koja bi vrsta tjelovježbe mogla najviše pomoći depresivnim osobama, kao i broj i trajanje tjelovježbe koja ljudima najviše pomaže. Potrebna su nova, veća istraživanja kako bi se utvrdilo da li je tjelovježba jednako učinkovita kao antidepresivi ili psihološke terapije.
Translated by: Croatian Branch of the Italian Cochrane Centre