Exercise as it relates to Disease/The long term effects of exercise on major depressive disorder

This is an in-depth analysis of the journal article “Exercise Treatment for Major Depression: Maintenance of Therapeutic Benefit at 10 Months” by Michael Babyak et al (2000).

What is the background to this research?
It has been long since known that exercise has many health benefits, even with mental health. In the last few decades, many studies have started focusing on the potential benefits for exercise on mental illnesses, such as depression and anxiety. The literature had a formed a consensus that there was an inverse correlation between exercise and depressive qualities, in those with depression. This article focuses on a time gap between exercise and mental health testing, to determine if these sorts of positive results were permanent, or at the very least, a long-term solution. The treatment guidelines at the time indicated that six months had to pass to reduce the risk of a relapse, thus this study was born. Four months of physical exercise, and then a follow up in six months to see if the participants still had fewer depressive symptoms than pre-treatment.

Where is the research from?
The current study was conducted in America and was published in the American Psychosomatic Society in the year 2000. The authors of this study have a long history in this area and have all worked on a previous study together “Effects of exercise training on older patients with major depression”. The current study served as a ‘daughter’ study to their previous study, which compared medical interventions with physical therapy. However, they wanted to know if the results of their study – that exercise could be considered equally effective to antidepressants, could be displayed over a longer term.

What kind of research was this?
This study is a randomised control trial (RCT), split into three sub-groups:
 * Exercise
 * Medication
 * Combined exercise and medication

What did the research involve?
This study was conducted with older participants, similar to their last study. There were 156 adult participants, all aged over 50, and met the DSM IV criteria for having major depressive disorder. These participants were all allowed to participate in the study after proving they had no alcohol/drug dependency, no antidepressant medication, and other reasonable conditions. The study used the same three surveys to evaluate participants at the pre-treatment, four month mark, and six month mark (DIS, HRSD and BDI). All evaluations of depression were treated in a clinical setting, aside from one telephone interview, conducted only due to the participant being unable to return to the laboratory.

The exercise group consisted of 16 weeks of exercise and were required to work between 70-85% of their maximum heart rate, calculated by a treadmill test. The exercise period would last for 30 minutes with a ten minute warm up and a five minute cool down.

The medication group received an antidepressant called sertraline, which reduces serotonin re-uptake. This particular drug was selected for the study based on its clinical success and has been shown to be particularly effective with the older population, which was the focus of the current study. A psychiatrist updated the dosage based on side effects and treatment response, every few weeks to keep the medication levels consistent.

The combined exercise and medication group contained both variables above.

What were the basic results?
The results for the current study were very positive. After four months, all trial groups had shown improvement (see Table 1), and after six months, the figures had all but increased. The exercise group exhibited the lowest level of depressive symptoms, with the medication group having the highest rate of relapse.

What conclusions can we take from this research?
The findings presented by the study do indeed suggest that medication is less effective, long-term at assisting to reduce depressive symptoms when compared to exercise. It has been shown to be a short-term solution, with more participants scoring lower on the depression surveys after four months, when compared to exercise, but didn’t continue to improve as the exercise group did. This study has shown that an exercise program with half an hour of 70% HR training, three times a week can be a reliable treatment for depression.

A follow up study of the same experiment found similar results described by the present study. In addition a study published in 2001 found that weight lifting had benefits on depression in the elderly, regardless of their heart rate.

Practical advice
The present study has made a real discovery in terms of long-term treatment for depression. Exercise is by far a greater long-term solution for depression, rather than medication, or a combination of the two. The recovery rates for depression for the exercise group were close to 90%, whilst the medication and combination groups sat around 60%. Participants who exercised showed a tendency to continue improving throughout the study, compared to the medication group.However, this study was conducted on the elderly population. Further research would have to be conducted to prove reliability with other age groups.

If you are interested in taking up an exercise program, please contact your GP for health advice, and see a personal trainer for an exercise program to help you reach your goals.

Further suggested reading: Exercise and Pharmacotherapy in Patients With Major Depression: One-Year Follow-Up of the SMILE Study. Hoffman et al (2011).

If you or someone you know is may be experiencing depression, please contact Beyond Blue on 1300 22 4636 or reach them at https://www.beyondblue.org.au/

If you or someone you know is suicidal call lifeline on 13 11 14 or https://www.lifeline.org.au/