Effectiveness of mindfulness based interventions in reducing depressive symptoms across mental disorders: A meta-analysis of randomized controlled trials

Mindfulness based interventions (MBIs) are increasingly recognised for their efficacy in treating depressive disorders. Depressive symptoms are prevalent across various disorders and can significantly impact outcomes, therefore being an important transdiagnostic target. Multiple randomized controlled Trials (RCTs) have explored this question in discrete disorders; however, evidence has never been meta-analysed transdiagnostically. The Prospero-registered (CRD42022352046) systematic review has been conducted on EMBASE, MEDLINE and PsychINFO using terms related to Randomised controlled trials, mindfulness and depression in clinical samples aged between 18 and 65. Random-effects models were performed to assess the effectiveness of MBIs, including Mindfulness based Cognitive Therapy (MBCT), Acceptance and Commitment Therapy (ACT), and Dialectical Behavioural Therapy (DBT), on depressive symptoms transdiagnostically. We conducted sensitivity, heterogeneity analyses, publication bias assessments, meta-regressions and assessed quality. Thirty-five studies, including participants from 12 different diagnostic categories, were included. The results revealed that MBCT, ACT, DBT and others are efficacious in treating depressive symptoms across psychiatric diagnoses compared to active control conditions, all with significant effect sizes. MBIs are effective in reducing depressive symptoms across psychiatric disorders. They should be considered as a potential cost-effective tool to be systematically implemented, not only in those with depression but across mental health disorders.