Exercise as it relates to Disease/Treatment of major depression: Can exercise help?

The following is a critique of the research paper Efficacy of exercise as an adjunct treatment for clinically depressed inpatients during the initial stages of antidepressant pharmacotherapy: An open randomized controlled trial, published in the Journal of Affective Disorders, 2016.

What is the background to this research?
Depression describes a number of mental health conditions characterised by a lowered mood or loss of interest and pleasure, loss of appetite, weight loss/gain, sleep disturbance, psychomotor agitation or retardation, energy decrease, sense of worthlessness, guilt, difficulty in concentrating, or thoughts of suicide. Epidemiological studies estimate the lifetime prevalence of depression at 10-15%. By 2030 depression will be one of the top three burdensome diseases in the world. Whilst pharmacological approaches are often implemented along with psychological interventions these are not often effective with only approximately 30% of patients responding to initial treatment. Others, despite adequate treatment do not achieve sufficient symptom relief or discontinue treatment due to side effects. 50% will have another depressive episode. Evidence suggests that treatment needs to be maximised as early as possible as increased duration and failed treatment responses reduce the chances of remission.

Several meta-analyses have shown aerobic exercise has a moderate effect on the reduction of symptoms in major depression. Exercise as an addition to the standard treatment of depression can be effective in reducing symptoms and both the WHO and NICE guidelines recommend implementing exercise as part of the standard treatment.

Where is the research from?
The authors of the research, Fabian Legrand and Elise Neff are from the Psychology and Medical Departments, University of Reims Champagne Ardenne, France. Fabian Legrand has published several articles in the areas of sports science and sports psychology in a number of peer recognised journals. The authors have made no statements regarding funding or any conflict of interest.

What kind of research was this?
The research was an open randomised controlled trial. A randomised control trial is the gold standard in research with the main aim to reduce systematic differences between treatment groups ensuring bias has no effect on the results of treatment. Ultimately, a double blind study where neither the patient or researcher is aware of the treatment is the best way reduce bias however, this is not always possible particularly in trials where exercise is the treatment. This type of trial is an open trial where both the researchers and treatment groups are aware of the intervention. In this study the first author supervised both the exercise and stretching interventions generally as one-on-one sessions, whereas the control group had no interaction possibly introducing bias and this was acknowledged by the authors.

What did the research involve?
The researchers between July 2011 and July 2015 recruited subjects from 124 inpatients admitted to a psychiatric unit for treatment of major depressive disorder at Public Health Establishment Mental of thr Marne EPSMM, Chalons-en-Champagne. To meet the inclusion criteria patients had to be diagnosed with major depressive disorder according to the DSM-IV criteria (provides a framework for classifying disorders and defining diagnostic criteria), antidepressant therapy for less than two weeks and a score of 29 or more on the Beck Depression Inventory, indicating severe depression. The Beck Depression Inventory is the most well-researched depression self-report inventory for use with adults. It is a 21-item, multiple-choice inventory designed to assess the level of depression in adults.

Patients were excluded if exercise was contraindicated (e.g. taking beta blockers or arthritis), exhibiting psychotic features or were receiving other therapies for depression such as electroconvulsive therapy. 48 were eligible to participate, of which 35 participated. The participants were predominately middle aged women and were randomly assigned to one of three study arms, aerobic exercise, stretching, or no intervention.

The exercise intervention consisted of 30 minutes daily brisk walking or jogging, for ten consecutive days at an intensity of 65-75% of age predicted maximal heart rate. Exercise sessions were performed outside in the hospital grounds. Those participants in the stretching group also performed 30 minutes of stretching for ten consecutive days inside the hospital in a room specifically set aside for these activities. Participants in the control group received no intervention other than prescribed antidepressants. Assessment of depressive symptoms was performed the day before and the day after completion of treatment using the Beck Depression Inventory. There were no differences in baseline depression scores between the groups.

Many studies have recruited participants who have been on antidepressants for different time periods and doses and as a such it is difficult to attribute the results to purely exercise alone. This study was unique in that it tried to standardise the period of antidepressant use as a confounding factor by recruiting participants who had been taking antidepressants for less than two weeks. However, due to French privacy legislation the daily dosage of antidepressant for each participant could not be collected. As the participants had only recently started drug therapy the authors assumed that participants would be prescribed standard doses for the first 4-8 weeks as part of standard clinical practice.

What were the basic results?
The authors demonstrated that the exercise group showed a significant decrease in depression scores as did the stretching group, whilst scores remained unchanged in the control group. The reduction was larger in the aerobic exercise group when compared to the control group and marginally larger than for the stretching group. No statistical difference was observed between the stretching and control group. A summary of the depression scores pre and post intervention is shown in the table below.

SD = Standard Deviation

According to the authors the results would indicate that a short endurance training program can lead to a significant reduction in depression symptoms in as little as ten days. The authors proposed the mechanism by which this was achieved was through the physiological changes that occur in the hippocampus which results in neurogenesis and expression of neurotrophic factors such as brain derived neurotrophic factor (BDNF).

What conclusions can we take from this research?
Based on the evidence presented by the authors exercise is likely to help in the treatment of major depression. Results for this study were similar to those achieved by others conducting studies into the effect of exercise on depression and exercise may be as effective as antidepressants for the relief of mild to moderate depression. Knapen et al. in their review state that physical exercise moderately reduces symptoms in major depression as do the results of other studies and meta-analyses.

Despite evidence that exercise reduces symptoms many studies have failed to provide insight into the most effective exercise variables to be used and the optimal dose is unknown. The majority of exercise research designed to improve depression has used the American College of Sports Medicine’s (ACSM) guidelines to promote and maintain health but there appears to be a dose response relationship. Further research to investigate the optimal dose is required to ensure the best outcome.

Practical advice
Whilst the optimal dose of exercise is still unknown, exercise at the current physical activity guidelines is likely to improve depression symptoms. Exercise is inexpensive, improves general well being and may help decrease depressive symptoms during the time it takes for antidepressant medication to show therapeutic effect. Before undertaking any exercise program participants should consult their medical practitioner. Developing an exercise program with the help of a qualified professional can reduce the associated health risks and optimise the benefits. Depression can often cause fatigue and lack of motivation and participating in supervised exercise can provide the impetus to exercise.

If you or someone you know is suffering from depression there is plenty of support. You can talk to someone on-line and the websites listed below have lots of helpful information. Not sure where to start? Your general practitioner can help you with a treatment plan. Sometimes life can be overwhelming and those suffering from depression are more likely to have suicidal thoughts. If someone you know is experiencing suicidal thoughts, ask them if they're OK, listen, and help them to get help.

Crisis Support: Lifeline: 13 11 14. Suicide Call Back Service: 1300 659 467

Further information/resources

 * https://www.beyondblue.org.au
 * https://www.blackdoginstitute.org.au
 * https://headspace.org.au
 * https://kidshelpline.com.au
 * https://mensline.org.au