Depressive symptoms are common comorbidities among breast cancer (BC) patients. Non-pharmacological therapies (NPTs) such as exercise and psychotherapy may reduce depressive symptoms; however, the evidence is inconclusive. The objective of this study is to evaluate if NPTs reduce depressive symptoms among BC patients.

A systematic review and meta-analysis of randomized clinical trials (RCTs) of NPTs for BC patients were performed. A literature search was conducted from eight databases in English, Portuguese and Spanish from 2006 to 2017. Inclusion criteria were: RCTs that evaluated depressive symptoms as a primary or secondary outcome that did not include pharmacological interventions and did include a non-intervened control group, with at least 30 participants in non-terminal BC stage with no current psychiatric illness. A meta-analysis for each NPT was performed with DerSimonian and Laird's method for the random effects model. Sensitivity analyses were conducted. Heterogeneity and publication bias were assessed.

A total of 41 eligible RCTs were identified. Overall, NPTs significantly reduced depressive symptoms (Summary standardized mean difference (SMD) = -0.516; 95%CI: -0.814, −0.218; I² = 96.2). Of the types of NPTs, psychotherapy significantly reduced depressive symptoms (Summary SMD = −0.819; 95% CI: -1.608, −0.030; I² = 91.53). A significant difference emerged for Mindfulness (Summary SMD = −0.241; 95% CI: -0.412, −0.070; I² = 28.6%) and yoga (Summary SMD = −0.305; 95% CI: -0.602, −0.007; I² = 41.0%) when the heterogeneity was reduced. No evidence of publication bias was observed.

Psychotherapy and mind-body therapies may reduce depressive symptoms in women with BC. Laughter and couples therapy warrant attention in future studies.