Effects of Mindfulness-Based Interventions on Depression in Patients With Breast Cancer: A Systematic Review and Meta-Analysis.

Abstract

We examined the effects of Mindfulness-based interventions (MBIs) on depressive symptoms in women with breast cancer and examined the moderating effects of participant characteristics, research methodologies, and features of interventions. We systematically searched 12 databases through November 2022 without date restrictions using the following search terms: (mindful* or meditation) AND (cancer OR neoplasm) AND (depress*). Studies included were primary studies evaluating MBIs in women with breast cancer who also had depression. Studies were included if they used a control group and were written in English. We used a random-effects model to compute effect sizes (ESs) using Hedges' g, forest plot, and Q and I2 statistics as measure of heterogeneity. We also requested moderator analyses. We found 19 studies with 2139 participants (49.4 ± 8.3 years old) that met inclusion criteria for this meta-analysis and systematic review. Overall, women in MBI groups demonstrated significantly lower levels of depression (g = 0.48, 95% CI:0.159, 0.792, P < .001) compared to women in control groups. Regarding moderators, providing MBIs with a home assignment component showed a significantly greater effect on decreasing depressive symptoms (g = 1.75) compared to MBIs without a home assignment component (g = 0.20). When researchers used concealed allocation technique, the interventions demonstrated lower effects on depression than when concealed allocation (g = 0.11vs g = 1.33, P ≤ .001) was not reported. Additionally, when researchers reported high rates of sample attrition, they found a lower effect size on depression (β = -.019, Q = 3.97, P = .046) indicating that attrition moderates the effect. MBIs are moderately effective interventions to reduce depressive symptoms among women with breast cancer. Clinicians might consider encouraging MBIs as adjunct/alternative treatments for women with breast cancer to manage symptoms of depression. Interventions that incorporat home assignments for practicing mindfulness are likely to have a greater effect on reducing depressive symptoms. Additionally, methods including concealed allocation and attrition rate were moderators of the effects of MBIs on depression in women with breast cancer.