Assessing the impact of Transcranial Direct Current Stimulation (tDCS) over the dorsolateral prefrontal cortex on social communication in children and adolescents with Autism Spectrum Disorder (ASD)

Introduction: Autism Spectrum Disorder (ASD) is characterized by persistent difficulties in social communication and behavior regulation. Although behavioral and pharmacological interventions exist, many yield limited improvements in these core areas. Transcranial Direct Current Stimulation (tDCS), a non-invasive neuromodulation technique, has shown potential for enhancing social and cognitive functions in individuals with ASD. This study evaluated the impact of tDCS, applied over the Dorsolateral Prefrontal Cortex (DLPFC), on social communication and behavioral outcomes in children and adolescents with ASD. Materials and methods: Two hundred sixty-five participants (3-18 years) with clinically confirmed ASD diagnoses (including ADOS-2 assessments) received a four-week course of tDCS over the DLPFC. Outcome measures included the Social Responsiveness Scale (SRS-2), the Autism Diagnostic Observation Schedule (ADOS-2), and the Aberrant Behavior Checklist (ABC). Family perceptions were explored through semi-structured interviews. Quantitative data were analyzed using paired t-tests and ANOVA, and qualitative data were examined via thematic analysis. No sham or control group was included. Results: Participants exhibited significant improvements in verbal and non-verbal communication (e.g., vocabulary, eye contact, gesture use), as well as reductions in repetitive behaviors and emotional dysregulation. Families reported decreased parental stress and enhanced family interactions, underscoring the intervention's feasibility and acceptability. Conclusion: tDCS over the DLPFC shows promise as an adjunctive intervention to improve social communication and behavioral outcomes in children and adolescents with ASD. However, the absence of a control group and the short duration of follow-up limit causal inferences. Further randomized, controlled, and longitudinal studies are needed to confirm these preliminary findings and determine their long-term clinical relevance.