Transcranial Direct Current Stimulation Improves Reward Processing in Children With ADHD

Area of Science:

• Neuroscience
• Cognitive Psychology
• Clinical Psychology

Background:

• Individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) exhibit impaired reward processing, affecting decision-making.
• Key brain regions involved in reward processing include the ventromedial prefrontal cortex (vmPFC) and dorsolateral prefrontal cortex (dlPFC).
• Deficits in tasks like delay discounting and risky decision-making are characteristic of ADHD.

Purpose of the Study:

• To investigate the effects of transcranial direct current stimulation (tDCS) on reward processing in children with ADHD.
• To determine if specific tDCS montages targeting the vmPFC and dlPFC can modulate cognitive tasks related to reward processing.
• To explore the role of the vmPFC and dlPFC in ADHD-related reward processing deficits.

Main Methods:

• Twenty children diagnosed with ADHD participated in the study.
• Three tDCS conditions were administered: anodal/cathodal over left dlPFC/right vmPFC, the reverse montage, and sham stimulation.
• Participants completed the Balloon Analogue Risk-Taking (BART) task and a chocolate delay discounting task during each stimulation session.

Main Results:

• A significant effect of the tDCS stimulation condition on emotional processing and decision-making was observed.
• Anodal tDCS over the right vmPFC combined with cathodal tDCS over the left dlPFC significantly reduced performance on risky decision-making and delay discounting tasks.
• The findings suggest a modulatory effect of targeted tDCS on reward-related cognitive functions in ADHD.

Conclusions:

• The left dlPFC and right vmPFC play crucial roles in reward processing in children with ADHD.
• Targeted tDCS interventions show potential for ameliorating specific cognitive deficits associated with ADHD.
• These results support the delay aversion theory of ADHD and highlight potential neurobiological targets for intervention.