Mindfulness practices and transcranial direct current stimulation: A systematic review and meta-analysis of self-reported mindfulness

There is a growing body of evidence investigating the effectiveness of combining psychological therapy and techniques with transcranial Direct Current Stimulation (tDCS) for facilitating meaningful change across a wide range of clinical and non-clinical domains. The objective of the current review was to examine mindfulness practices in combination with tDCS on self-reported mindfulness, given the well-established benefits of mindfulness on psychological health as well as the critical role of mindfulness processes as mediators of change in psychosocial intervention. Two databases were searched for sham-controlled studies of combined tDCS and mindfulness that included standardised mindfulness measures. Eight randomised trials met inclusion criteria. Results of the random-effects meta-analysis showed that mindfulness-based practices combined with active tDCS intervention revealed a small but significant increase in overall mindfulness as compared to sham tDCS and mindfulness (SMD = 0.24; 95% CI, 0.01, 0.48, p = 0.044). There was heterogeneity in the mindfulness practices, populations and number of stimulations, although there was general consistency in online tDCS location and intensity parameters (i.e., most commonly 2 mA anodal stimulation to the prefrontal cortex). The present findings provide evidence from sham RCTs that tDCS combined with mindfulness practice can augment self-reported mindfulness, lending support to a synergistic multimodal combination.