Lifestyle medicine for depression : a meta-analysis of randomized controlled trials

Background: The treatment effect of multi-component LM interventions on depressive symptoms has not yet been examined. Methods: We systematically searched six databases from inception to February 2020 to identify randomized controlled trials (RCTs) involving any multi-component LM interventions (physical activity, nutritional advice, sleep management, and/or stress management) on depressive symptoms relative to care as usual (CAU), waitlist (WL), no intervention (NI), or attention control (AC) comparisons. Results: Fifty studies with 8,479 participants were included. Multi-component LM interventions reduced depressive symptoms significantly relative to the CAU (p >.001; d = 0.20) and WL/NI (p > .01; d = 0.22) comparisons at immediate posttreatment. However, no significant difference was found when compared with AC. The intervention effects were maintained in the short-term (1- to 3-month follow-up) relative to the CAU comparison (p > .05; d = 0.25), but not in the medium- and long-term. The moderator analyses examining the effect of multi-component LM interventions compared with CAU suggested that the number of lifestyle factors adopted was a significant moderator. Although disease type was not a significant moderator, there was a tendency that the clinical effect of multi-component LM interventions was stronger (d = 0.45) in those diagnosed with major depression. No publication bias was detected. Limitations: Low number of RCTs available in some subgroup analyses prevented from finding meaningful effects. Results may not be extended to major depression, because data on secondary depression were captured. Conclusion: Multi-component LM interventions appeared to be effective in mitigating depressive symptoms; however, the magnitude of the clinical effect was small. Future research is needed to assess more comprehensive and individualized LM interventions which have a greater emphasis on motivational and compliance aspects and focus solely on individuals with depression.