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HomePsychiatryExercising even 50% of recommended amount reduces depression risk – Cambridge study

Exercising even 50% of recommended amount reduces depression risk – Cambridge study

Already known to help ease depression, regular exercise may also help prevent it, with people who exercised just half the recommended weekly amount lowering their risk for depression by 18%, according to research published in JAMA Psychiatry. However, those who were more active, meeting at least the minimum recommended physical activity level, reduced their risk for depression by 25%, compared with inactive people.

Exercise boosts the brain — and mental health

The findings stem from the analysis of data from 15 studies, involving 191,130 adults who were tracked for at least three years. Those who met activity guidelines did at least 150 minutes a week of moderate-intensity activity, such as brisk walking, as recommended in the Physical Activity Guidelines for Americans.

The Washington Post reports that mental health experts say nearly 10% of American adults struggle with some form of depression each year. Anti-depressant medication and talk therapy are commonly prescribed treatments, but exercise is also considered an effective treatment.

Exercise sparks the brainʼs release of endorphins, sometimes referred to as feel-good hormones. It can also quiet the mind, quelling the cycle of negative thoughts that often accompany depression, and can help reduce stress, improve sleep and boost self-esteem.

Urging doctors to encourage their patients to increase their physical activity, the researchers, from the University of Cambridge, wrote that the study’s findings suggest “significant mental health benefits from being physically active, even at levels below the public health recommendations”.

If less-active participants in the study had exercised more, they say, 11.5% of depression cases could have been prevented.

Study details

Association Between Physical Activity and Risk of Depression: A Systematic Review and Meta-analysis

Matthew Pearce, Leandro Garcia, Ali Abbas, et al.

Published in JAMA Psychiatry on 13 April 2022

Key Points
Question What is the dose-response association between physical activity and incident depression in adults?
Findings This systematic review and meta-analysis of 15 prospective studies including more than 2m person-years showed an inverse curvilinear association between physical activity and incident depression, with greater differences in risk at lower exposure levels. Adults meeting physical activity recommendations (equivalent to 2.5 h/wk of brisk walking) had lower risk of depression, compared with adults reporting no physical activity.
Meaning In this study, relatively small doses of physical activity were associated with substantially lower risks of depression.

Abstract

Importance Depression is the leading cause of mental health–related disease burden and may be reduced by physical activity, but the dose-response relationship between activity and depression is uncertain.
Objective To systematically review and meta-analyse the dose-response association between physical activity and incident depression from published prospective studies of adults.
Study Selection We included prospective cohort studies reporting physical activity at 3 or more exposure levels and risk estimates for depression with 3,000 or more adults and 3 years or longer of follow-up.
Main Outcomes and Measures The outcome of interest was depression, including (1) presence of major depressive disorder indicated by self-report of physician diagnosis, registry data, or diagnostic interviews and (2) elevated depressive symptoms established using validated cutoffs for a depressive screening instrument.

Results
Fifteen studies comprising 191,130 participants and 2  110, 588 person-years were included. An inverse curvilinear dose-response association between physical activity and depression was observed, with steeper association gradients at lower activity volumes; heterogeneity was large and significant (I2 = 74%; P < .001). Relative to adults not reporting any activity, those accumulating half the recommended volume of physical activity (4.4 marginal metabolic equivalent task hours per week [mMET-h/wk]) had 18% (95% CI, 13%-23%) lower risk of depression. Adults accumulating the recommended volume of 8.8 mMET hours per week had 25% (95% CI, 18%-32%) lower risk with diminishing potential benefits and higher uncertainty observed beyond that exposure level. There were diminishing additional potential benefits and greater uncertainty at higher volumes of physical activity. Based on an estimate of exposure prevalences among included cohorts, if less active adults had achieved the current physical activity recommendations, 11.5% (95% CI, 7.7%-15.4%) of depression cases could have been prevented.

Conclusions and Relevance
This systematic review and meta-analysis of associations between physical activity and depression suggests significant mental health benefits from being physically active, even at levels below the public health recommendations. Health practitioners should therefore encourage any increase in physical activity to improve mental health.

 

The Washington Post article – Exercising even half the recommended amount can help prevent depression (Open access)

 

JAMA Psychiatry article – Association Between Physical Activity and Risk of DepressionA Systematic Review and Meta-analysis (Open access)

 

See more from MedicalBrief archives:

 

Any exercise boosts mood and reduces depression

 

Physical exercise: A ‘fundamental’ psychiatric intervention

 

Benefits of outdoor walking groups

 

Exercise reduces symptoms of depression and anxiety in people with HIV

 

 

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