Noninvasive Brain Stimulation for Neurodevelopmental Disorders: A Systematic Review

Neurodevelopmental disorders (NDDs) affect brain development, leading to diverse cognitive, social, behavioral, and affective impairments. Noninvasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and transcranial photobiomodulation (tPBM), have been investigated as potential treatments for NDDs. The authors of this systematic review evaluated the literature on NIBS in NDDs, including double-blind, sham-controlled, randomized controlled trials. Following PRISMA guidelines and a registered protocol, the authors conducted a comprehensive search in PubMed, Embase, Cochrane Central Register of Controlled Trials, PsycInfo, and Scopus, identifying 23 studies. TMS showed promise for addressing hyperactivity, inattention, and working memory deficits in attention-deficit hyperactivity disorder (ADHD), with outcomes influenced by coil type (H5 vs. H6) and stimulation site (right vs. left dorsolateral prefrontal cortex). tDCS showed potential for improving inattention and executive function in ADHD, with limited effects observed on reducing symptom severity in autism spectrum disorder (ASD) and dyslexia. tPBM offered specific therapeutic benefits in reducing irritability in ASD. Although NIBS generally showed mild, transient adverse effects, isolated seizure events, such as one during TMS in ADHD, highlight the importance of rigorous safety protocols, especially in NDDs with elevated epilepsy risk. This review identified potential benefits of certain NIBS protocols in NDDs; however, high variability in methodologies, sample size limitations, and bias concerns underscore the need for further research to clarify the therapeutic efficacy and safety of NIBS among patients with NDDs.