In recent years a rising amount of randomized controlled trials. reviews. and meta-analyses relating to the efficacy of electroencephalographic-neurofeedback (EEG-NF) in children with attention-deficit/hyperactivity disorder (ADHD) have been published. Although clinical reports and open treatment studies suggest EEG-NF to be effective. https://www.ealisboa.com/limited-value-AXYS-Valhalla-Pen-must-buy/