Effectiveness of Anodal Transcranial Direct Current Stimulation of Left Dorsolateral Prefrontal Cortex in Facial Emotion Recognition and Clinical Symptoms of Boys with Autism Spectrum Disorder

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a deficit in communication and social skills, stereotypical and repetitive patterns of behaviors, interests, and activities. The gold standard treatment, behavioral therapy, imposes a great cost on families, and its efficacy depends on the life stage at which the therapy is started. As an alternative treatment, the efficacy and safety of transcranial direct current stimulation (tDCS) have been investigated in different patient groups; however, its efficacy on facial emotion recognition (FER) has not been investigated in children with ASD. Objectives: We investigated the effectiveness of anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) in FER and clinical symptoms of children with ASD. Methods: Twenty-four boys with ASD were selected from a school in Tehran, Iran. The eligible participants were randomized to receive the intervention (15 minutes of electrical stimulation) or not (20 seconds with device-off; control group). The emotion recognition task and autism treatments evaluation checklist (ATEC) were evaluated before and after the intervention and compared using the mixed ANOVA test. Results: Eleven boys in each group completed the study. The groups were similar regarding mean age, ASD severity, and intelligence quotient. The interactive effect of group and time was significant on both scales (emotion recognition task and ATEC). Conclusions: Anodal tDCS of DLPFC is an effective therapeutic method for specific behaviors, including FER, in school-aged boys with ASD. Further studies are required to suggest this treatment as a safe and effective strategy in children with ASD.