An evidence summary provided by PEDro with a CSP member's expert view
People with non-communicable chronic health conditions such as cardiovascular disease, cancer, respiratory disease and type 2 diabetes have higher rates of symptoms of depression than the general population. Symptoms of depression are also an adverse prognostic factor for these conditions. Aerobic exercise is accepted as an effective treatment option for depression in people without comorbid chronic disease. This systematic review aimed to estimate the effects of aerobic exercise compared to usual care on symptoms of depression in people with chronic diseases.
Sensitive searches of three databases identified (non-)randomised controlled trials that recruited adults with cardiovascular disease, cancer, respiratory disease or type 2 diabetes. Trials had to compare an aerobic exercise intervention (delivered at least twice per week, achieving at least moderate intensity exercise, for a minimum of four weeks) to usual care. Trials where usual care involved any type of exercise were excluded. The outcome was depression assessed by clinical assessment or symptoms of depression measured using a validated questionnaire. Two independent reviewers selected trials and extracted the data. Trial quality was evaluated with the Downs and Black checklist and certainty of the evidence with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) tool. Meta-analyses were reported as standardised mean difference (SMD) and 95 per cent confidence interval (CI).
Five subgroup analyses were pre-specified and estimated via meta-regression: (1) type of condition; (2) frequency of exercise equal to or less than three versus more than three sessions per week; (3) duration of sessions equal to or less than 30 versus more than 30 minutes; (4) length of programme of 12 weeks.
Thirty randomised controlled trials and two non-randomised trials (4,111 participants) were included in the review, 24 of which reported data suitable for meta-analysis. Interventions were delivered two to five sessions per week for 20 to 80 minutes per session for four to 24 weeks. Eleven studies included people with cardiovascular disease, 10 with cancer, two with respiratory disease and one with diabetes.
There was low certainty evidence that exercise improved symptoms of depression in people with chronic conditions (SMD 0.5, 95% CI 0.25 to 0.76, 24 trials) compared to usual care. There was moderate certainty evidence that aerobic exercise improved symptoms of depression in cardiovascular disease (SMD 0.67, 95% CI 0.35 to 0.99, 11 trials), and low certainty in cancer (SMD 0.22, 95% CI 0.07 to 0.37, 10 trials). There was low certainty of no effect in respiratory disease (SMD 0.98, 95% CI -0.01 to 1.96, 2 trials) and diabetes (SMD 0.11, 95% CI -0.43 to 0.65, 1 trial). Meta-regression did not show that session frequency, session duration or program length influenced effect size.
Aerobic exercise has potentially clinically important effects on symptoms of depression in people with chronic non-communicable diseases. Certainty of evidence is strongest in people with cardiovascular disease. The exercise programmes investigated targeted the health effects of the chronic conditions and were not specifically designed for symptoms of depression per se. It is also worth noting that this systematic review did not aim to assess the effect of exercise in people with clinical diagnosis of major depressive disorder.
Paula Manning Highly specialist physiotherapist (mental health) for St Andrews Healthcare and physical activity clinical champion for Public Health England in the East Midlands
This research shows the increased strength of evidence of the effects of at least two physical activity sessions per week on depression as a comorbidity to other non-communicable diseases.
The evidence could be used to support community and rehabilitation services to actively target depression alongside the other more well-known beneficial effects of physical activity.
Physical activity can be used as part of a restoration to a less depressed state and as mental health self-care in people with cardiovascular disease, cancer, diabetes and respiratory disease. It can be added to the patient advice and be outcome measured, to add weight to service reviews or bids to increase service provision. In those without perceived or recognised symptoms of depression, physical activity can be targeted as part of the mental ill health prevention agenda.
Although the evidence is less strong in diabetes and respiratory conditions, it demonstrates the need for more research in this area and could be part of a research project locally in the workplace using an appropriate mood monitoring tool. Mental health and physical health are so deeply associated that all service reviews would be advised to have mood as an indicator.
This evidence summary was provided by PEDro. PEDro is the Physiotherapy Evidence Database, a free database of randomised trials, systematic reviews and clinical practice guidelines in physiotherapy.
Beland M, et al. Aerobic exercise alleviates depressive symptoms in patients with a major non-communicable chronic disease: a systematic review and meta-analysis. British Journal of Sports Medicine. 2020;54:272-8
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