Health benefits, safety and cost of physical activity interventions for mental health conditions: A meta-review to inform translation efforts

Background: Mental illness is a leading cause of the global burden of disease. Physical activity (PA) can improve physical and mental health outcomes for people with mental illness, yet routine implementation of PA within standard care remains ad-hoc. The reasons for this are unclear, although the dissonance between the evidence produced in research settings and that needed in real-world environments may be key. Purpose: To explore the effectiveness of PA interventions as a treatment for mental illness. We synthesised past systematic reviews and meta-analyses. Methods: We conducted a systematic review of reviews from database inception to 09/2017. Reviews were included that considered any mental health condition (diagnosed via standardised criteria) and where PA interventions were a stand-alone or adjunctive treatment. Effectiveness was defined as outcomes that are important in real-world healthcare (i.e. expected clinical outcomes, intervention safety and cost). Results: From 4008 hits, 33 reviews (including 155 unique studies) were included and 32 reported that PA has a positive effect on at least one main outcome of interest (symptoms of mental illness, quality of life and/or physical health). There was inconsistent reporting of adverse events and no cost data was identified. The AMSTAR quality rating suggests inconsistencies in review quality. Conclusions: The research agenda must expand to report on outcomes that can support evidence translation efforts (i.e. cost and adverse events). Without such a shift, research in PA and mental health may fail to achieve translation to routine care and may have limited impact on patient outcomes.