Physical exercise and depression

Objectives: The objective was to review studies which used physical exercise as an intervention to treat major depression, focusing on methodology, mechanisms of action, types of physical exercise and treatment outcomes. Methods: Perform a search of the literature in the databases PsycINFO and PubMed 2000-2010 with 'major depression', 'exercise', 'outcome', 'physical activity' and 'aerobic training' as search terms. The inclusion criteria were: RCT treating depression with physical exercise with no limitations concerning age, gender or medication status. Results: Eight studies fulfilled the inclusion criteria and were included. Seven of the eight studies showed significantly improved mood and reduced depression. Physiological and psychological mechanisms may be more relevant to mechanisms of action than social factors. Physical exercise had the same positive effect as sertraline in two studies. Also physical exercise and sertraline given together in one of two studies had a positive effect. Three studies measured an increase in aerobic capacity, two with correlated mood improvements. One showed a correlation between increased muscle strength and reduced feelings of depression. Conclusion: Physical exercise can be an effective treatment against depression. A mood enhancing effect of exercise was identified in the interventions regardless of the mechanism of action. There is a need for more highly controlled clinical intervention studies treating depression with physical exercise, focusing on increasing the knowledge about mechanisms of action, type of exercise, intensity and frequency of exercise.