Combination of non-invasive brain stimulation with mindfulness-based interventions for anxiety and depression symptoms: systematic review and meta-analysis of randomized controlled trials

In this article we aimed synthesize all available evidence regarding the effects of non-invasive brain stimulation (NIBS) techniques combined with mindfulness-based interventions (MBIs) on mental health indicators. We performed a systematic review of randomized controlled trials evaluating NIBS/MBIs combinations in clinical populations and a random effects pairwise meta-analysis of studies evaluating anxiety and depression symptoms. After independent trial selection by two authors based on titles/abstracts, and then on full texts, twelve trials were retrieved. There was a large effect size favoring the NIBS/MBIs over the control intervention for anxiety symptoms (Cohen's d = - 0.82 (- 1.35, - 0.30), I² = 55%, moderate certainty of evidence). As for depression symptoms, there was a small-to-medium effect size that did not reach statistical significance (Cohen's d = - 0.24 (- 0.61, 0.13), I² = 30%, low certainty of evidence). MBIs/NIBS combination is feasible and well tolerated. There is preliminary evidence for its therapeutic promise. Future studies should inform combination choices by neural correlates of respective interventions and offer patients mindfulness familiarization before implementation of the NIBS/MBIs treatment.Trial registration CRD42022353971.