Transcranial direct current stimulation enhances effort maintenance in ADHD

Area of Science:

• Neuroscience
• Psychiatry
• Human Behavior

Background:

• Youth with ADHD often struggle with effort aversion, potentially linked to dopamine signaling deficits.
• Transcranial direct current stimulation (tDCS) may enhance dopaminergic activity in prefrontal cortex regions.
• The effectiveness of specific tDCS protocols for modulating effort in ADHD is not fully understood.

Purpose of the Study:

• To investigate the impact of a specific tDCS configuration on effort-related behaviors in children and adolescents with ADHD.
• To determine if tDCS can increase effort maintenance and invigoration during and after stimulation compared to a sham condition.

Main Methods:

• Twenty-four children and adolescents diagnosed with ADHD participated in the study.
• Participants received either 2 mA tDCS or sham stimulation for 20 minutes.
• Anodal stimulation targeted the ventromedial prefrontal cortex (PFC), with the cathode over the right dorsolateral PFC.
• A button-pressing task was used to measure effort maintenance and invigoration in anticipation of delayed monetary rewards.

Main Results:

• A significant increase in effort maintenance was observed both during and after tDCS compared to sham.
• No significant difference in effort invigoration was found during stimulation.
• A non-significant decrease in invigoration was noted after tDCS compared to sham, even after correction for multiple comparisons.

Conclusions:

• tDCS, with an anodal target on the ventromedial PFC and a cathodal target on the right dorsolateral PFC, effectively enhances effort maintenance in pediatric ADHD.
• This finding suggests a potential therapeutic application of targeted tDCS for improving motivational deficits in ADHD.