Investigating the effectiveness of transcranial direct current stimulation on the expressive language of children with autism spectrum disorder

Autism spectrum disorder (ASD) is a neuropsychological disorder, characterized by social skill deficits, language disorders, and repetitive behaviors.

The present study aimed to investigate the effects of transcranial direct current stimulation (tDCS) on the expressive language of children with ASD.

This semi-experimental study, with a pretest-posttest control-group design, was conducted on a statistical population of autistic children, aged 4-6 years, who were referred to the rehabilitation clinics of Yazd, Iran, during 2022. A total of 30 autistic children were randomly selected for this study. The scores of Newsha's Growth Assessment Test (2009) were compared in three intervals: before tDCS, after tDCS, and during follow-up. Data analysis was performed in SPSS Version 21, using repeated measures ANOVA.

The results of data analysis showed a significant difference in the mean expressive language scores of the experimental and control groups (P<0.05). The effect size of tDCS on expressive language scores was estimated at 0.421. The score of Newsha's Growth Assessment Test increased significantly in the experimental group after tDCS and during the follow-up compared to the control group (P=0.001).

The results showed that tDCS led to the improvement of the expressive language of children with ASD. Therefore, it is recommended to use this type of treatment as one of the complementary methods in the rehabilitation of ASD patients.