The potential impact of pro-BDNF, BDNF, and their ratio on cognitive functioning and the severity of symptoms in children with ADHD, in relation to anomalies in the electroencephalogram (EEG), which are common in this population [115,116,117], was recently evaluated in a study conducted by M. M. El-Saied et al. (2023) [118]. This evidence concerns the gene BDNF and attention deficit-hyperactivity disorder.