Meta-analysis of studies testing cognitive bias modification (CBM) intervention for emotion recognition bias

There is a growing need for cost-effective interventions for depression. Cognitive Bias Modification (CBM) techniques have been proposed as economical and scalable interventions that aim to change cognitive biases present in depression, with potential therapeutic effects. Penton-Voak et al. (2012) developed and tested a novel CBM intervention that focuses on retraining negative biases in emotion perception which, over a series of studies, has shown generally positive but unreliable and weak associations between CBM training and improvement in depressive symptoms. These inconsistent and modest effects observed in previous studies highlight the need for further research to determine whether this CBM intervention can reliably improve depressive symptoms and identify factors that may enhance its efficacy. The aim of this study is to meta-analyse the effectiveness of this emotional bias CBM training task on depressive symptoms. Additionally, this study aims to examine the mediating effect of emotion perception, the proposed therapeutic target of the intervention, on the relationship between CBM and depressive symptoms. We performed mediation analyses on 8 CBM studies separately (with a total of 1,250 participants) to determine whether the relationship between CBM and depressive symptoms is mediated by emotion processing. Following this, we conducted a meta-analysis on the direct, indirect, and total effects from the mediation analyses. The meta-analysis results suggest that there is no reliable positive total effect of CBM training on depressive symptoms. However, we found a mediation effect in which depressive symptom improvements are mediated by emotion processing. Modifying CBM to enhance its effectiveness in transferring improvements in emotional processing to depressive symptoms may increase its therapeutic potential.