[Benefits of exercise for people with schizophrenia: a systematic review]

Previous reviews of exercise and mental health have predominantly examined chronic illness and more recently, several psychiatric disorders. There is growing evidence that exercise can also be an effective treatment for major depressive disorders, anxiety disorders and alcohol dependence. Individuals with schizophrenia are more likely to be sedentary than the general population.

The objectives of this systematic review are to analyse the habits of physical activity and examine the literature that has investigated the use of exercise as treatment for schizophrenia.

We systematically reviewed psycINFO, Medline/PubMed, SportDiscus, Web of Sciences, and Cochrane Library. The searches of databases were conducted from database inception until September 2010, using a range of search terms to reflect both physical activity and schizophrenia. Studies were subsequently considered eligible if they reported on quantitative studies investigating the effect of physical activity upon some aspect of physical or mental health in individuals with schizophrenia.

Of the 139 articles retrieved, 19 studies met the inclusion criteria. In controlled studies, most authors have underlined the benefits of aerobic exercises. These programs may act both on positive symptoms (hallucinations) and on negative symptoms. According to certain studies, the positive effect may appear in a short time and at the end of the program. No studies assess long-term benefits. Small samples of self selected participants, inadequately selected control groups are common methodological weaknesses. A recent research has directly investigated the potential mechanism underpinning the positive benefits. The results indicated that hippocampal volume is plastic in response to aerobic exercise.

We discuss methodological and practical challenges to research in this area, and outline several research questions that future work should seek to address. Existing studies do suggest that lifestyles, physical activity interventions, or regular exercise programmes are possible in this population and can have beneficial effects on both the mental and physical health and well being of individuals with schizophrenia.

Research into the efficacy and safety of exercise as an intervention in schizophrenia is required to support the development of detailed, population-specific guidelines. Larger randomised studies are required before any definitive conclusions can be drawn. Although studies included in this review are small and used various measures of physical and mental health, results indicated that regular exercise programmes are possible in this population, and that they can have beneficial effects on both physical and mental health. Future research should address issues of programme adherence.