Effectiveness of universal multiple-risk lifestyle interventions in reducing depressive symptoms: Systematic review and meta-analysis.

Though many studies have explored the association between single-risk lifestyle interventions and depression, unhealthy lifestyle factors often co-occur, with adults engaging in two or more risk behaviours. To date, little is known about the effectiveness of universal multiple-risk lifestyle interventions to reduce depressive symptoms. We conducted a SR/MA to assess the effectiveness of universal multiple-risk lifestyle interventions (by promoting a healthy diet, physical activity and/or smoking cessation) to reduce depressive symptoms in adults. We searched MEDLINE, Scopus, CENTRAL, PsycINFO, WOS, OpenGrey, the ICTRP and other sources from inception to 16 September 2019. We selected only randomized controlled trials, with no restrictions on language or setting. Our outcome was the reduction of depressive symptoms. We calculated the standardized mean difference using random-effect models. Sensitivity, sub-group and meta-regression analyses were performed. Of the 9386 abstracts reviewed, 311 were selected for full-text review. Of these, 23 RCTs met the inclusion criteria, including 7558 patients from four continents. Twenty RCTs provided valid data for inclusion in the meta-analysis. The pooled SMD was -0.184 (95% CI, -0.311 to -0.057; p = 0.005). We found no publication bias, but heterogeneity was substantial (I 2 = 72%; 95% CI: 56% to 82%). The effectiveness disappeared when only studies with a low risk of bias were included. The quality of evidence according GRADE was low. Although a small preventive effect was found, the substantial heterogeneity and RCTs with lower risk of bias suggested no effectiveness of universal multiple-risk lifestyle interventions in reducing depressive symptoms in a varied adult population. Further evidence is required.