What does the evidence say?
A Cochrane review has recognised that although exercise improves depressive symptoms, the efficacy and form of exerise cannot be entirely ascertained. Although the quality of evidence still remains poor, it indicates that exercise on a long term basis may enhance the chanes of positive mood to remain consistent. Whether it enhances quality of life (QOF), remains inconclusive. However it is established that exercise is more efficacious compared to "no therapy" for alleviating symptoms of depression.
What does NICE say?
NICE recommends that patients sufering from mild-moderate depression should typicaly engage in physical activity for 45-60 minutes, thrice a week for 10-14 weeks. Exercise programmes implementing such practices should be facilitated by a trained practitioner and should be delivered as groups.
Undertsanding the evidence
Exercise is an advantageous self-help intervention alleviating depressive symptoms, reducing anxiety and reinforcing positive mood and motivation. Exercise is an inexpensive, easily accessible intervention which is beneficial in reducing the risks of developing other detrimental diseases e.g. cardiovascular diseasea and diabetes, In depression, exercise is as efficacious as 1st line therapy for mild-moderat depression. The Spiral model of reduced activity in depression, conveys the concept of exercise influencing mood.
The concept:
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If a patient lacks motivation this decreases the chance of physical activity during the day.
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This decreases the feeling of fulfillment, and pleasure in actvities, manifesting into lethargy.
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Consequenlty this causes the individual's mood to be lowered completing the cycle.
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​To counteract this cycle, researchers suggest that intervening and encouraging the patient to increase exercise (at stage 1 of the cycle) This enhances mood, self esteem dereasing the sense of fatigue and lack of motivation. It is also thought that it influences the neurobiological mechanisms such as:
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Monoamine metabolism: by enhancing serotonergic transmission
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HPA axis: decresaing cortisol concentrations
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Neurotrophic factors: encouraging BDNF and neurogenesis
How does exercise influence depression?
