Abstract:

Objective: Improving symptomology and cognitive deficits in neurodevelopmental disorders is a crucial
challenge. We examined whether neurostimulation protocols, which have been shown to yield long-term
effects when combined with cognitive training, could benefit children with Attention-deficit/hyperactiv
ity-disorder (ADHD), the most common neurodevelopmental disorder in childhood.
Methods: We used a randomized double-blind active-controlled crossover study of 19 unmedicated children
with ADHD, who received either anodal transcranial direct current stimulation (tDCS) over the left
dorsolateral prefrontal cortex (dlPFC) or random noise stimulation (tRNS) over the bilateral dlPFC, while
completing executive functions training.
Results: For our primary outcome, tRNS yielded a clinical improvement as indicated by the reduced
ADHD rating-scale score from baseline, and in comparison to the changes observed in tDCS. The effect
of brain stimulation one week after completion of treatment yielded further improvement, suggesting
a neuroplasticity-related effect. Finally, tRNS improved working memory compared to tDCS, and a larger
tRNS effect on ADHD rating-scale was predicted for those who showed the greatest improvement in
working memory.
Conclusions: We found that our intervention can have a lasting effect, rather than a merely immediate
effect as was shown for in previous medical interventions in ADHD.
Significance: Our results provide a promising direction toward a novel intervention in ADHD.