Efficacy of Mindfulness-Based Interventions for Negative Symptoms in Patients Diagnosed with Schizophrenia: a Meta-analysis

Objectives Mindfulness-based interventions (MBIs) can effectively relieve negative symptoms in patients with schizophrenia. However, the effect size of MBIs and their potential influencing factors remain unclear. Methods We searched different databases and performed a meta-analysis to determine the efficacy of MBIs for the treatment of negative symptoms in schizophrenia. Standard mean differences (SMDs) with 95% confidence intervals (CIs) were calculated to assess effect sizes of MBIs for negative symptoms. Subgroup analysis and meta-regression analysis were used to explore the potential influencing factors of the pooled SMD of MBIs for negative symptoms. Results We identified 26 randomized controlled trials including 1725 individuals with schizophrenia. We observed a small-to-large effect size of MBIs for negative symptoms. The pooled SMD of MBIs for negative symptoms was - 0.59 (95% CI: - 0.87 to - 0.32), with a heterogeneity (I-2) of 83.6% (95% CI: 76.9 to 88.4%; p < 0.01) based on a random effects model. In the subgroup analysis, significant differences were found with "Different Geographical Location of Treatment Study" (p < 0.01) and "Different Lengths of MBIs treatment" (p = 0.02). Meta-regression analysis showed that publication year was a significant predictor of the effect size of MBIs for negative symptoms (p < 0.001). Conclusions We identified a small-to-large effect size of MBIs to relieve negative symptoms in patients with schizophrenia. The number of sessions and different cultures were associated with the efficacy of MBT for negative symptoms