The effect of transcranial direct current stimulation (tDCS) combined with cognitive training on EEG spectral power in adolescent boys with ADHD: a double-blind, randomised, sham-controlled trial

Abstract

Transcranial direct current stimulation (tDCS) is a possible neurotherapeutic alternative to psychostimulants in Attention-Deficit/Hyperactivity Disorder (ADHD). However, very little is known regarding the mechanisms of action of tDCS in children and adolescents with ADHD. We conducted the first multi-session, sham-controlled study of anodal tDCS over right inferior frontal cortex (rIFC), a consistently under-functioning region in ADHD, combined with cognitive training (CT) in 50 children/adolescents with ADHD. This study investigated the underlying mechanisms of action on resting and Go/No-Go Task-based QEEG measures in a subgroup of 23 participants with ADHD (n, sham=10; anodal tDCS=13). We found no significant sham versus anodal tDCS group differences in QEEG spectral power during rest and Go/No-Go Task performance, no correlation between the QEEG and Go/No-Go Task performance, and no effect on clinical and cognitive outcome measures. These findings extend the null clinical or cognitive effects in our whole sample of 50 children/adolescents with ADHD. Our findings do not indicate multi-session anodal tDCS with CT over rIFC as a treatment for children/adolescents with ADHD. Larger RCTs should explore different protocols titrated to the individual and using comprehensive measures to assess cognitive, clinical, and neural effects of tDCS and its underlying mechanisms of action in ADHD.

Neurotherapeutics for Attention Deficit/Hyperactivity Disorder (ADHD): A Review

“…The study found that both groups improved in clinical symptoms and cognitive functions, but the improvement in the real versus sham tDCS in primary and secondary clinical outcome measures was significantly less pronounced [162] . Groups did not differ in a large battery of executive function cognitive outcome measures [162] nor in EEG measures within a smaller subsample of data collected from 26 participants only [163] . Furthermore, the real tDCS group had worse adverse effects related to mood, sleep and appetite immediately after stimulation [163].…”

“…Groups did not differ in a large battery of executive function cognitive outcome measures [162] nor in EEG measures within a smaller subsample of data collected from 26 participants only [163] . Furthermore, the real tDCS group had worse adverse effects related to mood, sleep and appetite immediately after stimulation [163].…”