Long-term effects of transcranial direct current stimulation in the treatment of autism spectrum disorder: A...

Area of Science:

• Neuroscience
• Developmental Pediatrics
• Clinical Psychology

Background:

• Autism spectrum disorder (ASD) presents significant challenges in social communication and behavior.
• Current interventions for ASD vary in efficacy and accessibility.
• Non-invasive brain stimulation techniques like tDCS are being explored as potential therapeutic options for ASD.

Purpose of the Study:

• To compare the effectiveness of 0, 5, and 20 sessions of transcranial direct current stimulation (tDCS) in reducing autism spectrum disorder (ASD) symptoms.
• To determine if a higher number of tDCS sessions offers superior outcomes compared to a lower number or sham treatment.

Main Methods:

• Thirty-six male children diagnosed with ASD were stratified and assigned to three groups: 20 sessions of sham tDCS (control), 5 active tDCS sessions followed by 15 sham sessions (5-tDCS), or 20 active tDCS sessions (20-tDCS).
• All participants engaged in special school activities.
• Autism severity was assessed using the Childhood Autism Severity Scale (CARS) as the primary outcome measure.

Main Results:

• Both the 5-tDCS and 20-tDCS groups showed significantly greater reductions in autism severity compared to the control group at multiple time points (days 5 and 14, months 6 and 12).
• No significant differences in symptom reduction were observed between the 5-tDCS and 20-tDCS groups.
• Clinically meaningful improvements were noted starting on day 5 for active tDCS groups and month 6 for the control group, with benefits sustained up to 12 months.

Conclusions:

• Five sessions of active tDCS appear to be as effective as 20 sessions in reducing ASD symptoms.
• Active tDCS treatment led to faster symptom improvement compared to sham treatment.
• The positive effects of tDCS on autism severity were maintained for at least one year.