Transcranial Direct Current Stimulation Modulates Neuronal Networks in Attention Deficit Hyperactivity Disorder

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuromodulation

Background:

• Attention deficit hyperactivity disorder (ADHD) is associated with prefrontal cortex underactivation and working memory (WM) deficits.
• Anodal transcranial direct current stimulation (tDCS) of the prefrontal cortex has shown efficacy in improving WM in general populations.

Purpose of the Study:

• To investigate the effects of anodal tDCS on prefrontal cortex activation and WM network connectivity in adolescents with ADHD.
• To assess if tDCS can modulate brain activity and functional connectivity related to WM performance in ADHD.

Main Methods:

• A double-blind, sham-controlled study involving 16 adolescents with ADHD.
• Participants received either anodal tDCS or sham stimulation over the left dorsolateral prefrontal cortex (DLPFC) during an n-back WM task, with simultaneous fMRI.
• Resting-state functional connectivity was assessed post-stimulation.

Main Results:

• Anodal tDCS significantly increased activation in the left DLPFC, premotor cortex, supplementary motor cortex, and precuneus compared to sham.
• tDCS demonstrated long-lasting effects, influencing resting-state functional connectivity and strengthening DLPFC connectivity within the WM network.
• Moderate behavioral effects were observed, suggesting potential but requiring further investigation.

Conclusions:

• Anodal tDCS effectively increases neuronal activation and connectivity in brain regions associated with WM in adolescents with ADHD.
• The findings suggest tDCS may modulate neural networks relevant to ADHD, but its clinical significance requires further study.
• Long-term effects and behavioral impact warrant additional research for therapeutic potential in ADHD treatment.