Background Transcranial direct current stimulation (tDCS) could be a side-effect-free alternative to psychostimulants in attention-deficit/hyperactivity disorder (ADHD). Although there is limited evidence for clinical and cognitive effects, most studies were small, single-session and stimulated left dorsolateral prefrontal cortex (dlPFC). No sham-controlled study has stimulated the right inferior frontal cortex (rIFC), which is the most consistently under-functioning region in ADHD, with multiple anodal-tDCS sessions combined with cognitive training (CT) to enhance effects. Thus, we investigated the clinical and cognitive effects of multi-session anodal-tDCS over rIFC combined with CT in double-blind, randomised, sham-controlled trial (RCT, ISRCTN48265228). Methods Fifty boys with ADHD (10–18 years) received 15 weekday sessions of anodal- or sham-tDCS over rIFC combined with CT (20 min, 1 mA). ANCOVA, adjusting for baseline measures, age and medication status, tested group differences in clinical and ADHD-relevant executive functions at posttreatment and after 6 months. Results ADHD-Rating Scale, Conners ADHD Index and adverse effects were significantly lower at post-treatment after sham relative to anodal tDCS. No other effects were significant. Conclusions This rigorous and largest RCT of tDCS in adolescent boys with ADHD found no evidence of improved ADHD symptoms or cognitive performance following multi-session anodal tDCS over rIFC combined with CT. These findings extend limited meta-analytic evidence of cognitive and clinical effects in ADHD after 1–5 tDCS sessions over mainly left dlPFC. Given that tDCS is commercially and clinically available, the findings are important as they suggest that rIFC stimulation may not be indicated as a neurotherapy for cognitive or clinical remediation for ADHD.

Neurocognitive models and previous neuroimaging work posit that auditory verbal hallucinations (AVH) arise due to increased activity in speech-sensitive regions of the left posterior superior temporal gyrus (STG). Here, we examined if patients with schizophrenia (SCZ) and AVH could be trained to down-regulate STG activity using real-time functional magnetic resonance imaging neurofeedback (rtfMRI-NF). We also examined the effects of rtfMRI-NF training on functional connectivity between the STG and other speech and language regions. Twelve patients with SCZ and treatment-refractory AVH were recruited to participate in the study and were trained to down-regulate STG activity using rtfMRI-NF, over four MRI scanner visits during a 2-week training period. STG activity and functional connectivity were compared pre- and post-training. Patients successfully learnt to down-regulate activity in their left STG over the rtfMRI-NF training. Post- training, patients showed increased functional connectivity between the left STG, the left inferior prefrontal gyrus (IFG) and the inferior parietal gyrus. The post-training increase in functional connectivity between the left STG and IFG was associated with a reduction in AVH symptoms over the training period. The speech-sensitive region of the left STG is a suitable target region for rtfMRI-NF in patients with SCZ and treatment-refractory AVH. Successful down-regulation of left STG activity can increase functional connectivity between speech motor and perception regions. These findings suggest that patients with AVH have the ability to alter activity and connectivity in speech and language regions, and raise the possibility that rtfMRI-NF training could present a novel therapeutic intervention in SCZ.

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BackgroundTranscranial direct current stimulation (tDCS) could be a side-effect free alternative to psychostimulants in Attention-Deficit/Hyperactivity Disorder (ADHD). Although there is limited evidence for clinical and cognitive effects, most studies were small, single-session, and stimulated left dorsolateral prefrontal cortex (dlPFC). No sham-controlled study has stimulated right inferior frontal cortex (rIFC), which is the most consistently under-functioning region in ADHD, with multiple sessions of anodal tDCS combined with cognitive training (CT) to enhance effects.Objective/HypothesisTo investigate clinical and cognitive effects of multi-session anodal tDCS over rIFC combined with CT in a double-blind, randomised, sham-controlled trial (RCT).Methods50 boys with ADHD (10-18 years) received 15 weekday sessions of anodal or sham tDCS over rIFC combined with CT (20mins, 1mA). ANCOVA, adjusting for baseline measures, age, and medication status, tested group differences in clinical and ADHD-relevant executive functions at posttreatment and after 6-months.ResultsADHD-Rating Scale, Conners ADHD Index, and adverse effects were significantly lower at post-treatment after sham relative to real tDCS. No other effects were significant.ConclusionsThis rigorous multi-session RCT of tDCS over the rIFC in ADHD combined with CT, showed no evidence of improvement of ADHD symptoms or cognitive performance. Findings extend limited meta-analytic evidence of cognitive and clinical effects in ADHD after 1-5 tDCS sessions over mainly left dlPFC. Given that tDCS is commercially and clinically available, the findings are important as they suggest that rIFC stimulation may not be indicated as a neurotherapy for cognitive or clinical remediation for ADHDHighlightstDCS has been suggested as an alternative treatment for ADHDWe combined 15-session anodal tDCS over the rIFC with cognitive training in ADHD childrenReal versus sham tDCS showed no cognitive or symptom improvementsConversely, real tDCS showed lower ADHD symptoms and higher adverse effectsMulti-session tDCS of rIFC shows no clinical or cognitive benefits in ADHD