Objective: We reviewed previously published meta-analyses of neurofeedback applied to children with ADHD and conducted a new meta-analysis of randomized controlled trials (RCTs) that updates previous results and incorporates methodological modifications. Method: Searches were carried out through PubMed, Sage, PsycINFO, SpringerLink, and Psicodoc. We used Hedges' (adjusted) g and a random-effects model. To assess heterogeneity, Q and I2 were calculated. We performed different analyses depending on the control groups, ADHD symptoms, pre- and/or posttreament data used and symptom evaluator. Results: We reviewed seven meta-analyses, and 17 studies were incorporated into the meta-analysis. RCTs support the efficacy of neurofeedback applied to ADHD when most proximal evaluators assess symptoms. Neurofeedback significantly improves inattention symptoms when possibly blinded evaluators assess symptoms. The preliminary results suggest that stimulant medication is more effective than neurofeedback. Conclusion: New RCTs that establish links between ADHD symptom measurements, subjects' learning after neurofeedback, and neurophysiological measures could improve the quality of the conclusions.
Keywords: ADHD; efficacy; meta-analysis; neurofeedback.