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

Repetitive Transcranial Photobiomodulation Improves Working Memory and Attention in Adults with ADHD: A 4-Week Follow-Up Study

Background: Working memory (WM) impairments and inattention symptoms are prevalent among adults with attention-deficit/hyperactivity disorder (ADHD). Transcranial photobiomodulation (tPBM) is a promising brain stimulation technique that may enhance cognitive function among adults with ADHD. Objectives: We aimed to explore the effects of tPBM on improving N-back WM and Continuous Performance Test-Identical Pairs (CPT-IP) attention tasks in adults with ADHD, as well as its baseline predictive factors. Methods: Forty-eight adults with ADHD underwent a 7-day tPBM intervention (720 s daily, 1064-nm wavelength, 250 mW/cm2 irradiance). Participants completed the N-back (1-back, 2-back, 3-back) WM, and CPT-IP (cpt-2, cpt-3, cpt-4) attention tasks at baseline (T1), after the first (T2), and seventh (T3) interventions, and during four weekly follow-ups (T4-T7). Safety was assessed using the Treatment Emergent Symptom Scale (TESS). Results: The participants showed significant improvements in the 2-back, 3-back, cpt-3, and cpt-4 tasks (all p < 0.001), with peak effect sizes observed at 2-3 weeks post-intervention (Cohen's d = 0.84-1.26). Lower baseline performance predicted greater improvement. The intervention was well-tolerated; three (6.3%) participants reported mild adverse events (TESS scores ≤2), all of which resolved spontaneously. Conclusions: tPBM is effective and well-tolerated for improving WM and attention in adults with ADHD, suggesting its potential use as a non-pharmacological approach for ADHD management.

New Perspectives on Non-Invasive Cerebellar Stimulation for Social and Affective Functions in Children and Adolescents

Cerebellar dysfunction affects socio-affective abilities beyond motor control. Recent studies suggest that non-invasive cerebellar neurostimulation can modulate social cognition networks, offering potential therapeutic benefits for children with autism, ADHD, and mood disorders. However, its application in pediatrics remains largely unexplored. This review summarizes emerging pediatric research on cerebellar transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). We discuss their mechanisms, potential benefits, and safety considerations, highlighting preliminary findings that suggest feasibility and effectiveness. Ethical concerns and technical challenges related to pediatric neuroanatomy and stimulation parameters are also addressed. While early results are promising, further clinical trials and neurophysiological studies are essential to optimize protocols and confirm long-term efficacy. Advancing our understanding of cerebellar involvement in socio-affective functions could lead to innovative rehabilitation strategies for neurodevelopmental disorders.

Effects of Frontal-Midline Theta Neurofeedback with Different Training Directions on Goal-Directed Attentional Control

As a significant component of executive function, goal-directed attentional control is crucial for cognitive processing and is closely linked to frontal-midline theta (FMT) rhythms. However, how up-regulation and down-regulation of FMT through neurofeedback training (NFT) impact goal-directed attention control remains unclear, especially for both short-term and long-lasting effects. Therefore, this study employed a single-blind sham-controlled between-subject design to answer this question. Forty-seven healthy adults were randomly assigned to the up-regulation, down-regulation, or sham control groups. Each group underwent one NFT session per day at the Fz electrode site for four consecutive days. All participants completed a visual search task before, immediately after the first, after the final, and one week following the last NFT session. The down-regulation group significantly reduced FMT activity during NFT and in the resting state (p < = 0.038), while the up-regulation group only showed an upward trend during the training phase (r = 0.721, p = 0.002). The behavioral performance showed no significant improvement in any group (p > 0.05). Importantly, the FMT learning efficacy in the up-regulation group revealed a significantly negative correlation with the change in switch cost (r = -0.602, p = 0.046). These findings suggest a close link between the up-regulation efficacy of FMT rhythms and goal-directed attentional control. In educational or clinical settings, it would be desirable to improve goal-directed attention through enhancement of FMT up-regulation efficacy of NFT in future work.

Neurofeedback for Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis

Importance

Neurofeedback has been proposed for the treatment of attention-deficit/hyperactivity disorder (ADHD) but the efficacy of this intervention remains unclear.

Objective

To conduct a meta-analysis of randomized clinical trials (RCTs) using probably blinded (ie, rated by individuals probably or certainly unaware of treatment allocation) or neuropsychological outcomes to test the efficacy of neurofeedback as a treatment for ADHD in terms of core symptom reduction and improved neuropsychological outcomes.

Data Sources

PubMed (MEDLINE), Ovid (PsycInfo, MEDLINE, Embase + Embase Classic), and Web of Science, as well as the reference lists of eligible records and relevant systematic reviews, were searched until July 25, 2023, with no language limits.

Study Selection

Parallel-arm RCTs investigating neurofeedback in participants of any age with a clinical ADHD or hyperkinetic syndrome diagnosis were included.

Data Extraction and Synthesis

Standardized mean differences (SMDs) with Hedges g correction were pooled in random effects meta-analyses for all eligible outcomes.

Main Outcomes and Measures

The primary outcome was ADHD total symptom severity assessed at the first postintervention time point, focusing on reports by individuals judged probably or certainly unaware of treatment allocation (probably blinded). Secondary outcomes were inattention and/or hyperactivity-impulsivity symptoms and neuropsychological outcomes postintervention and at a longer-term follow-up (ie, after the last follow-up time point). RCTs were assessed with the Cochrane risk of bias tool version 2.0.

Results

A total of 38 RCTs (2472 participants aged 5 to 40 years) were included. Probably blinded reports of ADHD total symptoms showed no significant improvement with neurofeedback (k = 20; n = 1214; SMD, 0.04; 95% CI, -0.10 to 0.18). A small significant improvement was seen when analyses were restricted to RCTs using established standard protocols (k = 9; n = 681; SMD, 0.21; 95% CI, 0.02 to 0.40). Results remained similar with adults excluded or when analyses were restricted to RCTs where cortical learning or self-regulation was established. Of the 5 neuropsychological outcomes analyzed, a significant but small improvement was observed only for processing speed (k = 15; n = 909; SMD, 0.35; 95% CI, 0.01 to 0.69). Heterogeneity was generally low to moderate.

Conclusions and Relevance

Overall, neurofeedback did not appear to meaningfully benefit individuals with ADHD, clinically or neuropsychologically, at the group level. Future studies seeking to identify individuals with ADHD who may benefit from neurofeedback could focus on using standard neurofeedback protocols, measuring processing speed, and leveraging advances in precision medicine, including neuroimaging technology.

Research progress of tDCS in the treatment of ADHD

TDCS is one of the most widely used non-invasive neuromodulation techniques, which changes the excitability of local cortical tissue by applying weak continuous direct current to the scalp, effectively improves the attention and concentration of ADHD children, and improves the impulse disorder of patients, but related research is still in its infancy. Based on a review of a large number of existing literatures and an analysis of the pathogenesis and principle of ADHD, this paper summarized the research on tDCS in the treatment of ADHD in recent years from the aspects of treatment mechanism, safety and stimulation parameters, and simply compared the application of tDCS with other non-traumatic neuromodulation techniques in the treatment of ADHD. The future development direction of this technology is further discussed.

Aberrant amplitude of low-frequency fluctuation and functional connectivity in children with different subtypes of ADHD: a resting-state fNIRS study

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with different subtypes of pathogenesis. Insufficient research on the subtypes of ADHD has limited the effectiveness of therapeutic methods.

METHODS

This study used resting-state functional near-infrared spectroscopy (fNIRS) to record hemodynamic signals in 34 children with ADHD-combined subtype (ADHD-C), 52 children with ADHD-inattentive subtype (ADHD-I), and 24 healthy controls (HCs). The amplitude of low-frequency fluctuation (ALFF) and the functional connectivity (FC) analysis were conducted for all subjects.

RESULTS

Compared with HCs, the ADHD group exhibited significantly increased ALFF and decreased FC. The ADHD-C group showed significantly higher ALFF in partial brain regions and significantly lower FC between multiple brain regions than participants with ADHD-I. The male group displayed a significant increase in ALFF in some brain regions, while no significant difference was found in FC when compared to the female group.

CONCLUSIONS

This study provides evidence to support the subtype classification of ADHD-I and ADHD-C, and the combined analysis of ALFF and FC has the potential to be a promising biomarker for the diagnosis of ADHD.

Study protocol of a randomised controlled trial of the effects of near-infrared spectroscopy neurofeedback training coupled with virtual reality technology in children with ADHD

BACKGROUND

The rise in the number of children diagnosed with attention-deficit/hyperactivity disorder (ADHD) highlights the need for effective interventions targeting attentional control. Although recent research has demonstrated the potential of neurofeedback training (NFT) for children with ADHD, most studies have been conducted in laboratory settings, raising questions about their real-world applicability. To address this issue, virtual reality (VR) may offer a solution to the ecological validity challenges encountered in NFT. By coupling NFT with VR, individuals can engage in self-regulating brain activity within a simulated, realistic environment. This study aims to investigate the efficacy of near-infrared spectroscopy (NIRS)-based NFT combined with VR in alleviating ADHD symptoms among children, addressing the need for interventions with practical relevance and effectiveness.

METHODS

This study aims to recruit 138 children aged 7-12 diagnosed with ADHD. Following baseline assessment, participants will be randomly assigned to one of three conditions: (1) NIRS-based NFT in a VR classroom setting; (2) conventional computerised cognitive training (active control) or (3) a waitlist control group. On completion of intervention sessions in the two training groups, all groups will undergo an assessment at time 2, with a follow-up assessment scheduled 2 months post-training for all participants. Primary outcomes will include measures of executive function, such as attentional control, response inhibition and working memory, along with changes in oxygenated and deoxygenated haemoglobin levels monitored by functional NIRS. Secondary outcome measures will comprise ratings of children's ADHD symptoms and executive function behaviours in daily life, reported by parents and teachers.

DISCUSSION

The three-arm randomised controlled trial will address research gaps regarding the effectiveness of NIRS-based NFT for children with ADHD, particularly when integrated with immersive VR technology. By combining NFT and VR, this study aims to simulate a real-world environment, potentially amplifying intervention effects. The findings from the study will provide evidence for the efficacy of this innovative intervention in improving executive function and alleviating ADHD symptoms.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Human Research Ethics Committee at the University of Hong Kong (Reference: EA200247). Results will be published in peer-reviewed journals and presented at conferences.

TRIAL REGISTRATION NUMBER

NCT05906485.

Effects of repetitive transcranial magnetic stimulation on prefrontal cortical activation in children with attention deficit hyperactivity disorder: a functional near-infrared spectroscopy study

Background

Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder characterized by inattention, impulsivity, and hyperactivity. With the continuous development of neuromodulation technology, Repetitive Transcranial Magnetic Stimulation (rTMS) has emerged as a potential non-invasive treatment for ADHD. However, there is a lack of research on the mechanism of rTMS for ADHD. Functional near infrared spectroscopy (fNIRS) is an optical imaging technique that reflects the brain function by measuring changes in blood oxygen concentration in brain tissue. Consequently, this research utilized fNIRS to examine the impact of rTMS on the core symptoms and prefrontal cortex activation in children with ADHD, which provides a reference for the clinical application of rTMS in the treatment of ADHD.

Methods

Forty children with ADHD were chosen as research subjects and randomly assigned to two groups: a treatment group (20 subjects) and a control group (20 subjects). The control group received non-pharmacological interventions, whereas the treatment group was administered rTMS in conjunction with non-pharmacological interventions. Clinical symptom improvement was evaluated using SNAP-IV scale scores both before and after treatment. Additionally, fNIRS was utilized to monitor alterations in the relative concentrations of oxyhemoglobin (HbO2) and deoxyhemoglobin (HbR) in the prefrontal cortex during resting state and during the Go/no-go task state, both pre- and post-treatment.

Results

In conclusion, the study comprised 17 participants in the treatment group and 18 in the control group. Initially, the SNAP-scale scores were comparable between the groups, with no significant differences observed (p > 0.05). Post-treatment, a notable reduction in SNAP-scale scores was evident (p < 0.05), with the treatment group exhibiting a more pronounced decrease (p < 0.05). Following the intervention, both groups demonstrated enhanced Resting-state functional connectivity (RSFC) in the prefrontal cortex, as indicated by a significant increase compared to pre-treatment levels (p < 0.05). Specifically, the treatment group showed superior RSFC in the left dorsolateral prefrontal cortex, right dorsolateral prefrontal cortex, left medial prefrontal cortex, and right medial prefrontal cortex compared to the control group (p < 0.05). However, no significant differences were noted in RSFC of the left and right temporal lobes between the two groups (p > 0.05). In the Go/no-go task, the treatment group recorded higher mean HbO2 concentrations in the aforementioned prefrontal cortical regions compared to the control group (p < 0.05). Conversely, no statistically significant disparities were observed in the left and right temporal lobes of both groups.

Conclusion

rTMS shows promise as a treatment for ADHD by modulating prefrontal cortical activation. fNIRS provides a valuable method for assessing these effects, offering insights into the neurobiological mechanisms underlying rTMS therapy.

Effects of fMRI neurofeedback of right inferior frontal cortex on inhibitory brain activation in children with ADHD

We aimed to replicate previous effects of functional magnetic resonance imaging neurofeedback (fMRI-NF) in right inferior frontal cortex (rIFC) on IFC activation during a Stop Task in a larger group of boys with attention-deficit/hyperactivity disorder (ADHD). The present double-blind, randomized controlled trial tested the effects of 15 runs of active versus sham fMRI-NF of rIFC on performance and activation associated with successful and failed inhibition versus Go trials during a tracking Stop task in 88 boys with ADHD (44 active; 44 sham), controlling for age and medication status. No significant group-by-time interaction effects were observed for performance or brain activation during the successful stop trials, and post hoc analysis showed very low numbers of active fMRI-NF learners. Nevertheless, during error monitoring, there was a significant group-by-time interaction effect on post-error reaction time slowing and in left IFC activation, which were both increased after active compared to sham fMRI-NF. The findings are in line with our previous observation of left IFC upregulation after fMRI-NF of rIFC relative to active fMRI-NF of parahippocampal gyrus. This highlights the potentially wider regional effects that fMRI-NF of a particular self-control target region has on other self-regulatory regions in ADHD. This article is part of the theme issue 'Neurofeedback: new territories and neurocognitive mechanisms of endogenous neuromodulation'.

Exploring neurofeedback as a therapeutic intervention for subjective cognitive decline

IMPACT STATEMENT

This study addresses the pressing issue of subjective cognitive decline in aging populations by investigating neurofeedback (NFB) as a potential early therapeutic intervention. By evaluating the efficacy of individualised NFB training compared to standard protocols, tailored to each participant's EEG profile, it provides novel insights into personalised treatment approaches. The incorporation of innovative elements and rigorous analytical techniques contributes to advancing our understanding of NFB's modulatory effects on EEG frequencies and cognitive function in aging individuals.

ABSTRACT

In the context of an aging population, concerns surrounding memory function become increasingly prevalent, particularly as individuals transition into middle age and beyond. This study investigated neurofeedback (NFB) as a potential early therapeutic intervention to address subjective cognitive decline (SCD) in aging populations. NFB, a biofeedback technique utilising a brain-computer interface, has demonstrated promise in the treatment of various neurological and psychological conditions. Here, we evaluated the efficacy of individualised NFB training, tailored to each participant's EEG profile, compared to a standard NFB training protocol aimed at increasing peak alpha frequency power, in enhancing cognitive function among individuals experiencing SCD. Our NFB protocol incorporated innovative elements, including the implementation of a criterion for learning success to ensure consistent achievement levels by the conclusion of the training sessions. Additionally, we introduced a non-learner group to account for individuals who do not demonstrate the expected proficiency in NFB regulation. Analysis of electroencephalographic (EEG) signals during NFB sessions, as well as before and after training, provides insights into the modulatory effects of NFB on EEG frequencies. Contrary to expectations, our rigorous analysis revealed that the ability of individuals with SCD to modulate EEG signal power and duration at specific frequencies was not exclusive to the intended frequency target. Furthermore, examination of EEG signals recorded using a high-density EEG showed no discernible alteration in signal power between pre- and post-NFB training sessions. Similarly, no significant effects were observed on questionnaire scores when comparing pre- and post-NFB training assessments.

Neurofeedback Training in Children with ADHD: A Systematic Review of Personalization and Methodological Features Facilitating Training Conditions

Objective. Current research on the effectiveness of neurofeedback (NFB) in children with attention-deficit/hyperactivity disorder (ADHD) is divided. Personalized NFB (pNFB), using pre-recorded individual electroencephalogram (EEG) features, is hypothesized to provide more reliable results. Our paper reviews available evidence on pNFB effectiveness and its methodological quality. Additionally, it explores whether other methodological features implying personalization are related to successful NFB. Methods. We conducted a systematic literature review on PubMed, PSYNDEX, PsycInfo and PsycArticles until November, 30, 2023. Studies that focused on pNFB in children with ADHD were selected, deviant studies excluded. Quality ratings by independent raters using Loney's1 criteria were conducted. Pooled effect sizes for NFB effects and methodological features were calculated. Results. Three of 109 studies included personalization and were reviewed in the full-text. In two studies, theta/beta-NFB was personalized using individual alpha peak frequencies (iAPF), whereas in one study, individual beta rhythms were trained. All three studies demonstrated significant short- and long-term improvements in ADHD symptoms, as assessed by questionnaires and objective performance tests, when compared to standard protocols (SP), sham-NFB, and control conditions. Twelve of 111 studies reported methodological features consistently related to NFB effectiveness. These features, including self-control instructions, feedback animations, timing of feedback presentation, behavioral performance, pre-recorded individual ERP-components and stimulant medication dosage, can be used to personalize NFB and enhance training success. Conclusion. Personalizing NFB with iAPF appears promising based on the existing -albeit small- body of research. Future NFB studies should include iAPF and other personalized features facilitating implementation consistently associated with treatment success.

The diagnostic effect of integrated visual and auditory continuous performance and event-related potentials in ADHD

OBJECTIVE

The development of objective assessment tools for attention deficit hyperactivity disorder (ADHD) has become a hot research topic. The aim was to explore the value of the P300 wave and integrated visual and auditory continuous performance test (IVA-CPT) in diagnosing ADHD.

METHODS

We enrolled 30 patients with ADHD and 30 age-matched healthy volunteers in a prospective study to evaluate differences in IVA-CPT and P300 indexes using student t test. These tools' accuracy in identifying ADHD patients was evaluated using receiver operating characteristic curve analysis. Additionally, the correlation between P300 and IVA-CPT in ADHD patients was evaluated using Pearson correlation analysis.

RESULTS

Compared with healthy volunteers, ADHD patients showed longer latency and lower amplitude, and had lower scores of IVA-CPT (P<0.01). There was no significant difference of latency, amplitude, and area below the amplitude of the P300 wave and in the score of IVA-CPT for age and gender within-ADHD groups (P>0.05). Moreover, receiver operating characteristic (ROC) curve showed high accuracy of P300 and IVA-CPT in identifying ADHD patients. Furthermore, both P300 index and IVA-CPT had high accuracy and performance in identification of ADHDin, ADHDhi, and ADHDcom. However, for different subtypes of ADHD, no significant differences were observed of ROC curves between subgroups (P>0.05). In addition, the performance in IVA-CPT was positively correlated with the amplitude, and negatively correlated with the latency of P300.

CONCLUSION

These results support the discriminant validity of P300 and IVA-CPT in distinguishing ADHD patients, providing a theoretical basis for P300 and IVA-CPT testing in the clinical diagnosis of ADHD.

Unraveling the spectrum: overlap, distinctions, and nuances of ADHD and ASD in children

This review explores the clinical presentation of similarities and differences in Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD). This paper investigates the deficits in executive function, social function, and emotional intelligence that are seen in both conditions and how the presence of both conditions can exacerbate these deficiencies. Understanding the clinical presentations in these domains is critical to refine diagnostic methods and treatments and improve outcomes for those affected by these neurodevelopmental disorders. The similarities in clinical presentation between ADHD and ASD present a significant diagnostic challenge, with individuals often exhibiting similar behaviors and difficulty navigating the complexities that encompass reacting to their environment. Further research is paramount in gaining more knowledge of the disorders and challenges faced by these individuals, especially those with the presence of both conditions.

Baseline brain volume predicts home-based transcranial direct current stimulation effects on inattention in adults with attention-deficit/hyperactivity disorder

BACKGROUND

Home-based transcranial direct current stimulation (Hb-tDCS) is a non-invasive brain stimulation technique that utilizes low-intensity electric currents delivered via scalp electrodes to modulate brain activity. It holds significant promise for addressing inattention in adults with attention-deficit/hyperactivity disorder (ADHD). However, its effectiveness varies among individuals, and predicting outcomes remains uncertain, partially due to the influence of individual differences in ADHD-related brain anatomy.

METHODS

We analyzed data from a subsample, composed by twenty-nine adult patients with ADHD, of the Treatment of Inattention Symptoms in Adult Patients with ADHD (TUNED) trial. Fourteen patients underwent active anodal right cathodal left dorsolateral prefrontal cortex (DLPFC) Hb-tDCS for 4 weeks and fifteen received sham-related tDCS intervention. Inattention outcome was evaluated at both baseline and endpoint (4th week). Baseline structural measures of the DLPFC, anterior cingulate cortex (ACC) and subcortical structures, previously associated with ADHD, were quantified. Several linear mixed models, with a three-way interaction between the fixed predictors brain volume or thickness, time, and treatment were calculated. Multiple comparison corrections were applied using the Benjamini-Hochberg method.

RESULTS

Baseline volume of the left DLPFC regions middle frontal gyrus (t (25) = 3.33, p-adjusted = 0.045, Cohen's d = 1.33, 95% CI = [0.45, 2.19]), inferior frontal gyrus (orbital part) (t (25) = 3.10, p-adjusted = 0.045, Cohen's d = 1.24, 95% CI = [0.37, 2.08]), and of the left ACC supragenual (t (25) = 3.15, p-adjusted = 0.045, Cohen's d = 1.26, 95% CI = [0.39, 2.11]) presented significant association with the inattentive score improvement only in the active tDCS group. More specifically, the smaller these regions were, the more the symptoms improved following anodal right cathodal left DLPFC Hb-tDCS.

CONCLUSION

Hb-tDCS was associated with greater improvement in brain areas related to attention regulation. Brain MRI can be potentially used to predict clinical response to tDCS in ADHD adults.

A Comparison of Effectiveness of Attention Process Training (APT) with Parenting Management Training (PMT) in Reducing Symptoms of Attention Deficit Hyperactivity Disorder

Objective: Child-oriented psychotherapies, such as Attention Process Training (APT), target ADHD symptoms directly, whereas family-oriented interventions, like Parent Management Training (PMT), address its functional impairments. The aim of this study was to compare the effectiveness of APT and PMT in treating ADHD symptoms. Method : This research was a randomized controlled trial in which 45 children (26 females and 19 males, with a mean age of 8.47 ± 1.66 years) with ADHD were selected conveniently and assigned randomly to one of three groups (PMT = 15, APT = 15, and CTRL = 15). The groups had no significant differences in ADHD severity. The PMT children were managed with parenting techniques. Children in the APT group practiced attention techniques, while children in the control group did not receive any intervention. Ritalin was prescribed to all the children in the three groups. The score on the Conners Parenting Rating Scale-Revised: Short form was the outcome variable. Results: Both interventions decreased ADHD symptoms severity more than the control group. Howver, the reduction in the APT group was more than in the PMT group (P-value < 0.001). The scores of 40% of the APT group and 80% of the PMT group did not fall below the cut-off point. In the APT group after the intervention, the inattention subscale was significantly lower than the hyperactivity subscale, while in the PMT group, the hyperactivity subscale was lower. The effect sizes of APT and PMT were 2.18 and 2.09, respectively. Conclusion: For ADHD, psychological interventions are crucial in addition to medication. According to the results of this study, APT is more effective for inattention symptoms, while PMT is more effective for hyperactivity symptoms. When selecting psychotherapy, the subtype of ADHD should be taken into account. Treatment sessions must also be completed according to intervention protocols.

Optimizing spatial specificity and signal quality in fNIRS: an overview of potential challenges and possible options for improving the reliability of real-time applications

The optical brain imaging method functional near-infrared spectroscopy (fNIRS) is a promising tool for real-time applications such as neurofeedback and brain-computer interfaces. Its combination of spatial specificity and mobility makes it particularly attractive for clinical use, both at the bedside and in patients' homes. Despite these advantages, optimizing fNIRS for real-time use requires careful attention to two key aspects: ensuring good spatial specificity and maintaining high signal quality. While fNIRS detects superficial cortical brain regions, consistently and reliably targeting specific regions of interest can be challenging, particularly in studies that require repeated measurements. Variations in cap placement coupled with limited anatomical information may further reduce this accuracy. Furthermore, it is important to maintain good signal quality in real-time contexts to ensure that they reflect the true underlying brain activity. However, fNIRS signals are susceptible to contamination by cerebral and extracerebral systemic noise as well as motion artifacts. Insufficient real-time preprocessing can therefore cause the system to run on noise instead of brain activity. The aim of this review article is to help advance the progress of fNIRS-based real-time applications. It highlights the potential challenges in improving spatial specificity and signal quality, discusses possible options to overcome these challenges, and addresses further considerations relevant to real-time applications. By addressing these topics, the article aims to help improve the planning and execution of future real-time studies, thereby increasing their reliability and repeatability.

A Digital Cognitive-Physical Intervention for Attention-Deficit/Hyperactivity Disorder: Randomized Controlled Trial

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders among children. Pharmacotherapy has been the primary treatment for ADHD, supplemented by behavioral interventions. Digital and exercise interventions are promising nonpharmacologic approaches for enhancing the physical and psychological health of children with ADHD. However, the combined impact of digital and exercise therapies remains unclear.

OBJECTIVE

The aim of this study was to determine whether BrainFit, a novel digital intervention combining gamified cognitive and exercise training, is efficacious in reducing ADHD symptoms and executive function (EF) among school-aged children with ADHD.

METHODS

This 4-week prospective randomized controlled trial included 90 children (6-12 years old) who visited the ADHD outpatient clinic and met the diagnostic criteria for ADHD. The participants were randomized (1:1) to the BrainFit intervention (n=44) or a waitlist control (n=46) between March and August 2022. The intervention consisted of 12 30-minute sessions delivered on an iPad over 4 weeks with 3 sessions per week (Monday, Wednesday, and Friday after school) under the supervision of trained staff. The primary outcomes were parent-rated symptoms of attention and hyperactivity assessed according to the Swanson, Nolan, and Pelham questionnaire (SNAP-IV) rating scale and EF skills assessed by the Behavior Rating Inventory of Executive Function (BRIEF) scale, evaluated pre and post intervention. Intention-to-treat analysis was performed on 80 children after attrition. A nonparametric resampling-based permutation test was used for hypothesis testing of intervention effects.

RESULTS

Among the 145 children who met the inclusion criteria, 90 consented and were randomized; ultimately, 80 (88.9%) children completed the study and were included in the analysis. The participants' average age was 8.4 (SD 1.3) years, including 63 (78.8%) male participants. The most common ADHD subtype was hyperactive/impulsive (54/80, 68%) and 23 (29%) children had severe symptoms. At the endpoint of the study, the BrainFit intervention group had a significantly larger improvement in total ADHD symptoms (SNAP-IV total score) as compared to those in the control group (β=-12.203, 95% CI -17.882 to -6.523; P<.001), owing to lower scores on the subscales Inattention (β=-3.966, 95% CI -6.285 to -1.647; P<.001), Hyperactivity/Impulsivity (β=-5.735, 95% CI -8.334 to -3.137; P<.001), and Oppositional Defiant Disorder (β=-2.995, 95% CI -4.857 to -1.132; P=.002). The intervention was associated with significant reduction in the Metacognition Index (β=-6.312, 95% CI -10.973 to -1.650; P=.006) and Global Executive Composite (β=-5.952, 95% CI -10.214 to -1.690; P=.003) on the BRIEF. No severe intervention-related adverse events were reported.

CONCLUSIONS

This novel digital cognitive-physical intervention was efficacious in school-age children with ADHD. A larger multicenter effectiveness trial with longer follow-up is warranted to confirm these findings and to assess the durability of treatment effects.

TRIAL REGISTRATION

Chinese Clinical Trial Register ChiCTR2300070521; https://www.chictr.org.cn/showproj.html?proj=177806.

Efficacy and safety of transcranial pulse stimulation in young adolescents with attention-deficit/hyperactivity disorder: a pilot, randomized, double-blind, sham-controlled trial

Background

This is the first study to evaluate the efficacy and safety of transcranial pulse stimulation (TPS) for the treatment of attention-deficit/hyperactivity disorder (ADHD) among young adolescents in Hong Kong.

Methods

This double-blind, randomized, sham-controlled trial included a TPS group and a sham TPS group, encompassing a total of 30 subjects aged 12-17 years who were diagnosed with ADHD. Baseline measurements SNAP-IV, ADHD RS-IV, CGI and executive functions (Stroop tests, Digit Span) and post-TPS evaluation were collected. Both groups were assessed at baseline, immediately after intervention, and at 1-month and 3-month follow-ups. Repeated-measures ANOVAs were used to analyze data.

Results

The TPS group exhibited a 30% reduction in the mean SNAP-IV score at postintervention that was maintained at 1- and 3-month follow-ups.

Conclusion

TPS is an effective and safe adjunct treatment for the clinical management of ADHD.

Clinical trial registration

ClinicalTrials.Gov, identifier NCT05422274.

Antihypertensive treatment during pregnancy induces long-term changes in gut microbiota and the behaviors of the attention deficit hyperactivity disorder offspring

The pathogenesis of attention-deficit/hyperactivity disorder (ADHD) has not been fully elucidated. Gestational hypertension could double the probability of ADHD in the offspring, while the initial bacterial communication between the mother and offspring has been associated with psychiatric disorders. Thus, we hypothesize that antihypertensive treatment during pregnancy may abate the impairments in neurodevelopment of the offspring. To test this hypothesis, we chose Captopril and Labetalol, to apply to pregnant spontaneously hypertensive rat (SHR) dams and examined the outcomes in the male offspring. Our data demonstrated that maternal treatment with Captopril and Labetalol had long-lasting changes in gut microbiota and behavioral alterations, including decreased hyperactivity and increased curiosity, spatial learning and memory in the male offspring. Increased diversity and composition were identified, and some ADHD related bacteria were found to have the same change in the gut microbiota of both the dam and offspring after the treatments. LC-MS/MS and immunohistochemistry assays suggested elevated expression of brain derived neurotrophic factor (BDNF) and dopamine in the prefrontal cortex and striatum of offspring exposed to Captopril/ Labetalol, which may account for the improvement of the offspring's psychiatric functions. Therefore, our results support the beneficial long-term effects of the intervention of gestational hypertension in the prevention of ADHD.

Corticostriatal causality analysis in children and adolescents with attention-deficit/hyperactivity disorder

AIM

The effective connectivity between the striatum and cerebral cortex has not been fully investigated in attention-deficit/hyperactivity disorder (ADHD). Our objective was to explore the interaction effects between diagnosis and age on disrupted corticostriatal effective connectivity and to represent the modulation function of altered connectivity pathways in children and adolescents with ADHD.

METHODS

We performed Granger causality analysis on 300 participants from a publicly available Attention-Deficit/Hyperactivity Disorder-200 dataset. By computing the correlation coefficients between causal connections between striatal subregions and other cortical regions, we estimated the striatal inflow and outflow connection to represent intermodulation mechanisms in corticostriatal pathways.

RESULTS

Interactions between diagnosis and age were detected in the superior occipital gyrus within the visual network, medial prefrontal cortex, posterior cingulate gyrus, and inferior parietal lobule within the default mode network, which is positively correlated with hyperactivity/impulsivity severity in ADHD. Main effect of diagnosis exhibited a general higher cortico-striatal causal connectivity involving default mode network, frontoparietal network and somatomotor network in ADHD compared with comparisons. Results from high-order effective connectivity exhibited a disrupted information pathway involving the default mode-striatum-somatomotor-striatum-frontoparietal networks in ADHD.

CONCLUSION

The interactions detected in the visual-striatum-default mode networks pathway appears to be related to the potential distraction caused by long-term abnormal information input from the retina in ADHD. Higher causal connectivity and weakened intermodulation may indicate the pathophysiological process that distractions lead to the impairment of motion planning function and the inhibition/control of this unplanned motion signals in ADHD.

The efficacy of real versus sham external Trigeminal Nerve Stimulation (eTNS) in youth with Attention-Deficit/Hyperactivity Disorder (ADHD) over 4 weeks: a protocol for a multi-centre, double-blind, randomized, parallel-group, phase IIb study (ATTENS)

BACKGROUND

Attention Deficit/Hyperactivity Disorder (ADHD), if severe, is usually treated with stimulant or non-stimulant medication. However, users prefer non-drug treatments due to side effects. Alternative non-medication treatments have so far only shown modest effects. External trigeminal nerve stimulation (eTNS) is a minimal risk, non-invasive neuromodulation device, targeting the trigeminal system. It was approved for ADHD in 2019 by the USA Food and Drug administration (FDA) based on a small proof of concept randomised controlled trial (RCT) in 62 children with ADHD showing improvement of ADHD symptoms after 4 weeks of nightly real versus sham eTNS with minimal side effects. We present here the protocol of a larger confirmatory phase IIb study testing efficacy, longer-term persistency of effects and underlying mechanisms of action.

METHODS

A confirmatory, sham-controlled, double-blind, parallel-arm, multi-centre phase IIb RCT of 4 weeks of eTNS in 150 youth with ADHD, recruited in London, Portsmouth, and Southampton, UK. Youth with ADHD will be randomized to either real or sham eTNS, applied nightly for 4 weeks. Primary outcome is the change in the investigator-administered parent rated ADHD rating scale. Secondary outcomes are other clinical and cognitive measures, objective hyperactivity and pupillometry measures, side effects, and maintenance of effects over 6 months. The mechanisms of action will be tested in a subgroup of 56 participants using magnetic resonance imaging (MRI) before and after the 4-week treatment.

DISCUSSION

This multi-centre phase IIb RCT will confirm whether eTNS is effective in a larger age range of children and adolescents with ADHD, whether it improves cognition and other clinical measures, whether efficacy persists at 6 months and it will test underlying brain mechanisms. The results will establish whether eTNS is effective and safe as a novel non-pharmacological treatment for ADHD.

TRIAL REGISTRATION

ISRCTN82129325 on 02/08/2021, https://doi.org/10.1186/ISRCTN82129325 .

Near-infrared spectroscopy and electroencephalography neurofeedback for binge-eating disorder: an exploratory randomized trial

BACKGROUND

Binge-eating disorder (BED) co-occurs with neurobehavioral alterations in the processing of disorder-relevant content such as visual food stimuli. Whether neurofeedback (NF) directly targeting them is suited for treatment remains unclear. This study sought to determine feasibility and estimate effects of individualized, functional near-infrared spectroscopy-based real-time NF (rtfNIRS-NF) and high-beta electroencephalography-based NF (EEG-NF), assuming superiority over waitlist (WL).

METHODS

Single-center, assessor-blinded feasibility study with randomization to rtfNIRS-NF, EEG-NF, or WL and assessments at baseline (t0), postassessment (t1), and 6-month follow-up (t2). NF comprised 12 60-min food-specific rtfNIRS-NF or EEG-NF sessions over 8 weeks. Primary outcome was the binge-eating frequency at t1 assessed interview-based. Secondary outcomes included feasibility, eating disorder symptoms, mental and physical health, weight management-related behavior, executive functions, and brain activity at t1 and t2.

RESULTS

In 72 patients (intent-to-treat), the results showed feasibility of NF regarding recruitment, attrition, adherence, compliance, acceptance, and assessment completion. Binge eating improved at t1 by -8.0 episodes, without superiority of NF v. WL (-0.8 episodes, 95% CI -2.4 to 4.0), but with improved estimates in NF at t2 relative to t1. NF was better than WL for food craving, anxiety symptoms, and body mass index, but overall effects were mostly small. Brain activity changes were near zero.

CONCLUSIONS

The results show feasibility of food-specific rtfNIRS-NF and EEG-NF in BED, and no posttreatment differences v. WL, but possible continued improvement of binge eating. Confirmatory and mechanistic evidence is warranted in a double-blind randomized design with long-term follow-up, considering dose-response relationships and modes of delivery.

Attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD; also known as hyperkinetic disorder) is a common neurodevelopmental condition that affects children and adults worldwide. ADHD has a predominantly genetic aetiology that involves common and rare genetic variants. Some environmental correlates of the disorder have been discovered but causation has been difficult to establish. The heterogeneity of the condition is evident in the diverse presentation of symptoms and levels of impairment, the numerous co-occurring mental and physical conditions, the various domains of neurocognitive impairment, and extensive minor structural and functional brain differences. The diagnosis of ADHD is reliable and valid when evaluated with standard diagnostic criteria. Curative treatments for ADHD do not exist but evidence-based treatments substantially reduce symptoms and/or functional impairment. Medications are effective for core symptoms and are usually well tolerated. Some non-pharmacological treatments are valuable, especially for improving adaptive functioning. Clinical and neurobiological research is ongoing and could lead to the creation of personalized diagnostic and therapeutic approaches for this disorder.

Treatment of adult attention-deficit hyperactivity disorder (ADHD) with transcranial direct current stimulation (tDCS): study protocol for a parallel, randomized, double-blinded, sham-controlled, multicenter trial (Stim-ADHD)

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation treatment used as an alternative or complementary treatment for various neuropsychiatric disorders, and could be an alternative or add-on therapy to psychostimulants in attention-deficit hyperactivity disorder (ADHD). Previous studies provided some evidence for improvements in cognition and clinical symptoms in pediatric and adult ADHD patients. However, data from multi-center randomized controlled trials (RCTs) for this condition are lacking. Thus, our aim is to evaluate short- and mid-term effects of tDCS in this multi-center, randomized, double blind, and sham-controlled, parallel group clinical trial with a 1:1 randomization ratio. Primary endpoint is the total score of DSM-IV scale of the internationally established Conners' Adult ADHD Rating Scales (German self-report screening version, CAARS-S-SR), at day 14 post-intervention (p.i.) to detect short-term lasting effects analyzed via analyses of covariance (ANCOVAs). In case of significant between-groups differences at day 14 p.i., hierarchically ordered hypotheses on mid-term lasting effects will be investigated by linear mixed models with visit (5 time points), treatment, treatment by visit interaction, and covariates as fixed categorical effects plus a patient-specific visit random effect, using an unstructured covariance structure to model the residual within-patient errors. Positive results of this clinical trial will expand the treatment options for adult ADHD patients with tDCS and provide an alternative or add-on therapy to psychostimulants with a low risk for side effects.Trial Registration The trial was registered on July 29, 2022 in the German Clinical Trials Register (DRKS00028148).

BOLD Activation During the Application of MOXO-CPT in School Patients With and Without Attention Deficit Hyperactivity Disorder

INTRODUCTION

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that affects 3% of children in the world.

OBJECTIVE

In this work, we seek to compare the different brain activations of pediatric patients with and without ADHD.

METHODS

A functional resonance examination with BOLD contrast was applied using the MOXO-CPT test (Continuous Performance test with single and double visual-auditory distractors).

RESULTS

Differences in BOLD activation were observed indicating that control children regularly presented negative BOLD activations that were not found in children with ADHD. Inhibitory activity in audiovisual association zones in control patients was greater than in patients with ADHD. The inhibition in the frontal and motor regions in the controls contrasted with the overactivation of the motor areas in patients with ADHD, this, together with the detection of cerebellar activation which attempted to modulate the responses of the different areas that lead to executive failure in patients with ADHD.

CONCLUSIONS

In view of these results, it can be argued that the lack of inhibition of ADHD patients in their executive functions led to a disorganization of the different brain systems.

Translating Decades of Neuroscience Research into Diagnostic and Treatment Biomarkers for ADHD

In this chapter, we review scientific findings that form the basis for neuroimaging and neurophysiological biomarkers for ADHD diagnosis and treatment. We then highlight the different challenges in translating mechanistic findings into biomarkers for ADHD diagnosis and treatment. Population heterogeneity is a primary barrier for identifying biomarkers of ADHD diagnosis, which requires shifts toward dimensional approaches that identify clinically useful subgroups or prospective biomarkers that can identify trajectories of illness, function, or treatment response. Methodological limitations, including emphasis on group level analyses of treatment effects in small sample sizes, are the primary barriers to biomarker discovery in ADHD treatment. Modifications to clinical trials, including shifting towards testing biomarkers of a priori prediction of functionally related brain targets, treatment response, and side effects, are suggested. Finally, future directions for biomarker work are discussed.

Exploring the Potential "Brain-Cognition-Behavior" Relationship in Children With ADHD Based on Resting-State Brain Local Activation and Functional Connectivity

OBJECTIVE

Exploring how abnormal brain function in children with ADHD affects executive function and ultimately leads to behavioral impairment provides a theoretical basis for clinically targeted neurotherapy and cognitive training.

METHOD

Amplitude of low frequency fluctuations (ALFF), regional homogeneity (ReHo), and seed-based FC were analyzed in 53 ADHD and 52 healthy controls. The "brain-cognition-behavior" relationship was further explored using mediation analysis.

RESULTS

ADHD showed abnormal local activation in the middle temporal gyrus (MTG), inferior occipital gyrus and inferior frontal gyrus (IFG) and reduced FC between the IFG and the cerebellum. ADHD diagnosis may affect ALFF of MTG and further modulate shift and finally affect inattentive symptoms. It may also affect the total symptoms through the FC of the IFG with the cerebellum.

CONCLUSION

ADHD showed extensive spontaneous activity abnormalities and frontal-cerebellar FC impairments. Localized functional abnormalities in the MTG may affect the shift in EF, resulting in attention deficit behavior.

Lack of association between behavioral development and simplified topographical markers of the sleep EEG in infancy

The sleep EEG mirrors neuronal connectivity, especially during development when the brain undergoes substantial rewiring. As children grow, the slow-wave activity (SWA; 0.75-4.25 Hz) spatial distribution in their sleep EEG changes along a posterior-to-anterior gradient. Topographical SWA markers have been linked to critical neurobehavioral functions, such as motor skills, in school-aged children. However, the relationship between topographical markers in infancy and later behavioral outcomes is still unclear. This study aims to explore reliable indicators of neurodevelopment in infants by analyzing their sleep EEG patterns. Thirty-one 6-month-old infants (15 female) underwent high-density EEG recordings during nighttime sleep. We defined markers based on the topographical distribution of SWA and theta activity, including central/occipital and frontal/occipital ratios and an index derived from local EEG power variability. Linear models were applied to test whether markers relate to concurrent, later, or retrospective behavioral scores, assessed by the parent-reported Ages & Stages Questionnaire at ages 3, 6, 12, and 24 months. Results indicate that the topographical markers of the sleep EEG power in infants were not significantly linked to behavioral development at any age. Further research, such as longitudinal sleep EEG in newborns, is needed to better understand the relationship between these markers and behavioral development and assess their predictive value for individual differences.

Clinical and cognitive effects of external trigeminal nerve stimulation (eTNS) in neurological and psychiatric disorders: a systematic review and meta-analysis

This pre-registered (CRD42022322038) systematic review and meta-analysis investigated clinical and cognitive outcomes of external trigeminal nerve stimulation (eTNS) in neurological and psychiatric disorders. PubMed, OVID, Web of Science, Chinese National Knowledge Infrastructure, Wanfang, and VIP database for Chinese technical periodicals were searched (until 16/03/2022) to identify trials investigating cognitive and clinical outcomes of eTNS in neurological or psychiatric disorders. The Cochrane Risk of Bias 2.0 tool assessed randomized controlled trials (RCTs), while the Risk of Bias of Non-Randomized Studies (ROBINS-I) assessed single-arm trials. Fifty-five peer-reviewed articles based on 48 (27 RCTs; 21 single-arm) trials were included, of which 12 trials were meta-analyzed (N participants = 1048; of which ~3% ADHD, ~3% Epilepsy, ~94% Migraine; age range: 10-49 years). The meta-analyses showed that migraine pain intensity (K trials = 4, N = 485; SMD = 1.03, 95% CI[0.84-1.23]) and quality of life (K = 2, N = 304; SMD = 1.88, 95% CI[1.22-2.53]) significantly improved with eTNS combined with anti-migraine medication. Dimensional measures of depression improved with eTNS across 3 different disorders (K = 3, N = 111; SMD = 0.45, 95% CI[0.01-0.88]). eTNS was well-tolerated, with a good adverse event profile across disorders. eTNS is potentially clinically relevant in other disorders, but well-blinded, adequately powered RCTs must replicate findings and support optimal dosage guidance.

Distinct effects of different neurofeedback protocols on the neural mechanisms of response inhibition in ADHD

OBJECTIVE

In attention deficit/hyperactivity disorder (ADHD), impaired response inhibition is frequently observed. A promising non-pharmacological treatment is electroencephalography (EEG)-neurofeedback (NF) training. However, the widely used theta-down/beta-up regulation (↓θ↑β) NF protocol may not be optimal for targeting these deficits. We examined how neurofeedback protocols training the upregulation of theta and/or beta power affect inhibitory control in children and adolescents with ADHD.

METHODS

64 patients with ADHD took part in the three NF trainings. Aside from parent-reported ADHD symptoms and behavioural performance data, neurophysiological parameters collected via a Go/Nogo task and corrected to account for intraindividual variability were compared in a pre-post design and to an ADHD (n = 20) as well as a typically developing control group (n = 24).

RESULTS

The examined NF protocols resulted in similar improvements in response inhibition with the neurophysiological mechanisms differing substantially. The upregulation of theta led to a specific Nogo-P3 increase, while training beta upregulation as well as the combined protocol resulted in less specific effects.

CONCLUSIONS

This study shows distinct effects of different theta/beta-neurofeedback protocols on the neural mechanisms underlying improvements in response inhibition in patients with ADHD.

SIGNIFICANCE

These effects shed further light on the oscillatory dynamics underlying cognitive control in ADHD and how these may be targeted in neurofeedback treatments.

Transcranial random noise stimulation combined with cognitive training for treating ADHD: a randomized, sham-controlled clinical trial

Non-invasive brain stimulation has been suggested as a potential treatment for improving symptomology and cognitive deficits in Attention-Deficit/Hyperactivity Disorder (ADHD), the most common childhood neurodevelopmental disorder. Here, we examined whether a novel form of stimulation, high-frequency transcranial random noise stimulation (tRNS), applied with cognitive training (CT), may impact symptoms and neural oscillations in children with ADHD. We conducted a randomized, double-blind, sham-controlled trial in 23 unmedicated children with ADHD, who received either tRNS over the right inferior frontal gyrus (rIFG) and left dorsolateral prefrontal cortex (lDLPFC) or sham stimulation for 2 weeks, combined with CT. tRNS + CT yielded significant clinical improvements (reduced parent-reported ADHD rating-scale scores) following treatment, compared to the control intervention. These improvements did not change significantly at a 3-week follow-up. Moreover, resting state (RS)-EEG periodic beta bandwidth of the extracted peaks was reduced in the experimental compared to control group immediately following treatment, with further reduction at follow-up. A lower aperiodic exponent, which reflects a higher cortical excitation/inhibition (E/I) balance and has been related to cognitive improvement, was seen in the experimental compared to control group. This replicates previous tRNS findings in adults without ADHD but was significant only when using a directional hypothesis. The experimental group further exhibited longer sleep onset latencies and more wake-up times following treatment compared to the control group. No significant group differences were seen in executive functions, nor in reported adverse events. We conclude that tRNS + CT has a lasting clinical effect on ADHD symptoms and on beta activity. These results provide a preliminary direction towards a novel intervention in pediatric ADHD.

Psychological and Medical Treatments for Binge-Eating Disorder: A Research Update

Binge-eating disorder (BED), characterized by recurrent binge eating in the absence of regular weight-compensatory behaviors, is the most common eating disorder, associated with pronounced mental and physical sequelae. An increasing body of research documents the efficacy of diverse approaches to the treatment of this disorder, summarized in meta-analyses. This research update narratively reviewed randomized-controlled trials (RCTs) on the psychological and medical treatment of BED published between January 2018 to November 2022, identified through a systematic literature search. A total of 16 new RCTs and 3 studies on previous RCTs providing efficacy- and safety-related data were included. Regarding psychotherapy, confirmatory evidence supported the use of integrative-cognitive therapy and, with lower effects, brief emotion regulation skills training for binge eating and associated psychopathology. Behavioral weight loss treatment was revealed to be efficacious for binge eating, weight loss, and psychopathology, but its combination with naltrexone-bupropion did not augment efficacy. New treatment approaches were explored, including e-mental-health and brain-directed treatments, mostly targeting emotion and self-regulation. Additionally, different therapeutic approaches were evaluated in complex stepped-care models. In light of these advances, future research is necessary to further optimize effects of evidence-based treatments for BED, through improvement of existing or development of new treatments, based on mechanistic and/or interventional research, and/or tailoring treatments to personal characteristics in a precision medicine approach.

Evaluating the efficacy and safety of transcranial pulse stimulation on adolescents with attention deficit hyperactivity disorder: Study protocol of a pilot randomized, double-blind, sham-controlled trial

Background

Traditional treatment alone might not effectively control the severity of attention deficit hyperactivity disorder (ADHD) symptoms. Transcranial pulse stimulation (TPS) is a non-invasive brain stimulation (NIBS) technology used on older adults with mild neurocognitive disorders and adults with major depressive disorder. However, there has been no study conducted on young adolescents with ADHD. This will be the first nationwide study evaluating the efficacy and safety of TPS in the treatment of ADHD among young adolescents in Hong Kong.

Methods

This study proposes a double-blinded, randomized, sham-controlled trial including TPS as an intervention group and a sham TPS group. Both groups will be measured at baseline (T1), immediately after the intervention (T2), and at the 1-month (T3) and 3-month follow-ups (T4).

Recruitment

A total of 30 subjects aged between 12 and 17 years, diagnosed with attention deficit hyperactivity disorder (ADHD), will be recruited in this study. All subjects will be computer randomized into either the intervention group or the sham TPS group on a 1:1 ratio.

Intervention

All subjects in each group will have to undertake functional MRI (fMRI) before and after six 30-min TPS sessions, which will be completed in 2 weeks' time.

Outcomes

Baseline measurements and post-TPS evaluation of the ADHD symptoms and executive functions will also be conducted on all participants. The 1- and 3-month follow-up periods will be used to assess the long-term sustainability of the TPS intervention. For statistical analysis, ANOVA with repeated measures will be used to analyze data. Missing data were managed by multiple imputations. The level of significance will be set to p &lt; 0.05.

Significance of the study

Results emerging from this study will generate new knowledge to ascertain whether TPS can be used as a top-on treatment for ADHD.

Clinical trial registration

clinicaltrails.gov, identifier: NCT05422274.

A randomized, sham-controlled trial of high-definition transcranial direct current stimulation on the right orbital frontal cortex in children and adolescents with attention-deficit hyperactivity disorder

OBJECTIVE

This study aimed to find out the clinical and cognitive effects of high-definition transcranial direct current stimulation (HD-tDCS) on the right orbital frontal cortex (OFC) in the treatment of attention deficit hyperactivity disorder (ADHD).

METHODS

A total of 56 patients with ADHD were recruited as subjects and completely and randomly divided into the HD-tDCS group and the Sham group. A 1.0 mA anode current was applied to the right OFC. The HD-tDCS group received real stimulation, while the Sham group received sham stimulation in 10 sessions of treatment. ADHD symptom assessment (the SNAP-IV Rating Scale and the Perceived Stress Questionnaire) was carried out before treatment, after the 5th and 10th stimuli, and at the 6th week after the end of all stimulations, while the cognitive effect was assessed by the Integrated Visual and Auditory Continuous Performance Test (IVA-CPT), the Stroop Color and Word Test (Stroop), and the Tower of Hanoi (TOH). Repeated-measure ANOVA was used to find out the results of both groups before and after treatment.

RESULTS

A total of 47 patients completed all sessions and evaluations. Their SNAP-IV score, their PSQ score, the mean visual and auditory reaction times by IVA-CPT, the interference RT of Stroop Color and Word, and the number of completed steps of TOH did not change with intervention time before and after treatment (P > 0.0031). However, the integrated visual and audiovisual commission errors and the TOH completion time results of the HD-tDCS group were significantly decreased after the 5th intervention, the 10th intervention, and the 6th week of intervention follow-up compared to the Sham group (P < 0.0031).

CONCLUSION

This study draws cautious conclusions that HD-tDCS does not significantly alleviate the overall symptoms of patients with ADHD but leads to significant improvements in the cognitive measures of attention maintenance. The study also attempted to fill in the gaps in research studies on HD-tDCS stimulation of the right OFC.

CLINICAL TRIAL REGISTRATION

ChiCTR2200062616.

Double-Blind, Sham-Controlled Randomized Trial Testing the Efficacy of fMRI Neurofeedback on Clinical and Cognitive Measures in Children With ADHD

OBJECTIVE

Functional MRI neurofeedback (fMRI-NF) could potentially be a novel, safe nonpharmacological treatment for attention deficit hyperactivity disorder (ADHD). A proof-of-concept randomized controlled trial of fMRI-NF of the right inferior frontal cortex (rIFC), compared to an active control condition, showed promising improvement of ADHD symptoms (albeit in both groups) and in brain function. However, comparison with a placebo condition in a larger trial is required to test efficacy.

METHODS

This double-blind, sham-controlled randomized controlled trial tested the effectiveness and efficacy of fMRI-NF of the rIFC on symptoms and executive functions in 88 boys with ADHD (44 each in the active and sham arms). To investigate treatment-related changes, groups were compared at the posttreatment and 6-month follow-up assessments, controlling for baseline scores, age, and medication status. The primary outcome measure was posttreatment score on the ADHD Rating Scale (ADHD-RS).

RESULTS

No significant group differences were found on the ADHD-RS. Both groups showed similar decreases in other clinical and cognitive measures, except for a significantly greater decrease in irritability and improvement in motor inhibition in sham relative to active fMRI-NF at the posttreatment assessment, covarying for baseline. There were no significant side effects or adverse events. The active relative to the sham fMRI-NF group showed enhanced activation in rIFC and other frontal and temporo-occipital-cerebellar self-regulation areas. However, there was no progressive rIFC upregulation, correlation with ADHD-RS scores, or transfer of learning.

CONCLUSIONS

Contrary to the hypothesis, the study findings do not suggest that fMRI-NF of the rIFC is effective in improving clinical symptoms or cognition in boys with ADHD.

The therapeutic role of repetitive transcranial magnetic stimulation in children with attention deficit/hyperactivity disorder in Egypt a randomized sham controlled clinical trial

Background

Repetitive transcranial magnetic stimulation showed some evidence for improving symptoms of ADHD along with its relative safety, thus could serve as a treatment strategy or an alternative to stimulant medication. Accordingly, 60 children with ADHD were assessed, and 30 participants were allocated to the rTMS group and received 15 sessions of rTMS over the right dorsolateral prefrontal cortex combined with Atomoxetine 1.2 mg/kg/day. The other 30 participants were allocated to the Sham group and received 15 sessions of sham rTMS and atomoxetine 1.2 mg/kg/day. Clinical assessments of ADHD symptoms and severity were done and compared at 3 points, before treatment, after receiving 15 sessions of rTMS and follow-up 1 month after the last rTMS session, using Conner’s Parent Rating Scale-Revised-Long form, Children’s Global Assessment Scale, and Clinical Global Impression.

Results

The two groups show significant improvement in the T scores of all CPRS subscales, CGI and CGAS. However, the rTMS group had a significantly more improvement than the sham group in inattention, total ADHD severity, CGI, and CGAS after rTMS and continued to the follow-up after 1 month.

Conclusions

rTMS is an efficacious intervention for treating ADHD, and combined rTMS and atomoxetine is superior to atomoxetine alone in improving attention deficit symptoms and total ADHD symptoms severity.

Trial registration

PACTR, PACTR202110558451583. Registered 25 June 2021. Approved 29 October 2021- Retrospectively registered, https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=15968.

Treatment biomarkers for ADHD: Taking stock and moving forward

The development of treatment biomarkers for psychiatric disorders has been challenging, particularly for heterogeneous neurodevelopmental conditions such as attention-deficit/hyperactivity disorder (ADHD). Promising findings are also rarely translated into clinical practice, especially with regard to treatment decisions and development of novel treatments. Despite this slow progress, the available neuroimaging, electrophysiological (EEG) and genetic literature provides a solid foundation for biomarker discovery. This article gives an updated review of promising treatment biomarkers for ADHD which may enhance personalized medicine and novel treatment development. The available literature points to promising pre-treatment profiles predicting efficacy of various pharmacological and non-pharmacological treatments for ADHD. These candidate predictive biomarkers, particularly those based on low-cost and non-invasive EEG assessments, show promise for the future stratification of patients to specific treatments. Studies with repeated biomarker assessments further show that different treatments produce distinct changes in brain profiles, which track treatment-related clinical improvements. These candidate monitoring/response biomarkers may aid future monitoring of treatment effects and point to mechanistic targets for novel treatments, such as neurotherapies. Nevertheless, existing research does not support any immediate clinical applications of treatment biomarkers for ADHD. Key barriers are the paucity of replications and external validations, the use of small and homogeneous samples of predominantly White children, and practical limitations, including the cost and technical requirements of biomarker assessments and their unknown feasibility and acceptability for people with ADHD. We conclude with a discussion of future directions and methodological changes to promote clinical translation and enhance personalized treatment decisions for diverse groups of individuals with ADHD.

Evidence for modulation of planning and working memory capacities by transcranial direct current stimulation in a sample of adults with attention deficit hyperactivity disorder

BACKGROUND AND OBJECTIVE

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder that affects up to 2.8% of the adult population. Albeit pharmacological and behavioral therapies alleviate some core symptoms of ADHD, they do not avail cognitive dysfunction adequately. Executive dysfunction has been considered to have a principal role in ADHD and has previously been linked to activity alterations in the prefrontal cortex. Transcranial Direct Current Stimulation (tDCS) is a noninvasive brain stimulation technique that may modulate prefrontal cortex activity and induce neuroplasticity, with preliminary results in ADHD. The aim of the present study is to assess the effect of repeated tDCS on measures of executive functions in adults with ADHD.

METHOD

In this randomized double-blind sham-controlled study, 22 adults with ADHD were allocated into two groups and were administered five consecutive sessions of 2 mA active/sham tDCS over the dorsolateral prefrontal cortex (right anodal/left cathodal). A neuropsychological test battery was administered before the first session and immediately after the last session.

RESULTS

The maximum number of digits and the total number of correct trials in the Digit Span Backward test increased in the active group (p = 0.017). The total move score in the Tower of London test decreased (p = 0.033), suggesting better planning ability. However, no significant differences were observed on Stroop Test and Trail Making Test after tDCS.

DISCUSSION

The present study corroborates the modulating effects of tDCS on planning and working memory in a small group of adults with ADHD. Our results highlighted that cognitive functions are modulable using tDCS in adults with ADHD.

Transcranial Direct Current Stimulation vs Sham for the Treatment of Inattention in Adults With Attention-Deficit/Hyperactivity Disorder: The TUNED Randomized Clinical Trial

IMPORTANCE

Transcranial direct current stimulation (tDCS) may improve symptoms of inattention in adults with attention-deficit/hyperactivity disorder (ADHD). However, previous trials are characterized by small sample sizes, heterogeneous methodologies, and short treatment periods using clinic-based tDCS.

OBJECTIVE

To determine the efficacy and safety of home-based tDCS in treating inattention symptoms in adult patients with ADHD.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, double-blind, parallel, sham-controlled clinical trial (tDCS for the Treatment of Inattention Symptoms in Adult Patients With ADHD [TUNED]), conducted from July 2019 through July 2021 in a single-center outpatient academic setting. Of 277 potential participants screened by phone, 150 were assessed for eligibility on site, and 64 were included. Participants were adults with ADHD, inattentive or combined subtype. Exclusion criteria included current stimulant drug treatment, current moderate to severe symptoms of depression or anxiety, diagnosis of bipolar disorder with a manic or depressive episode in the last year, diagnosis of schizophrenia or another psychotic disorder, and diagnosis of autism spectrum disorder; 55 of participants completed follow-up after 4 weeks.

INTERVENTIONS

Thirty-minute daily sessions of home-based tDCS for 4 weeks, 2 mA anodal-right and cathodal-left prefrontal stimulation with 35-cm2 carbon electrodes.

MAIN OUTCOMES AND MEASURES

Inattentive scores in the clinician-administered version of the Adult ADHD Self-report Scale version 1.1 (CASRS-I).

RESULTS

Included in this trial were 64 participants with ADHD (31 [48%] inattentive presentation and 33 [52%] combined presentation), with a mean (SD) age of 38.3 (9.6) years. Thirty participants (47%) were women and 34 (53%) were men. Fifty-five finished the trial. At week 4, the mean (SD) inattention score, as measured with CASRS-I, was 18.88 (5.79) in the active tDCS group and 23.63 (3.97) in the sham tDCS group. Linear mixed-effects models revealed a statistically significant treatment by time interaction for CASRS-I (βinteraction = -3.18; 95% CI, -4.60 to -1.75; P < .001), showing decreased symptoms of inattention in the active tDCS group over the 3 assessments compared to the sham tDCS group. Mild adverse events were more frequent in the active tDCS group, particularly skin redness, headache, and scalp burn.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, daily treatment with a home-based tDCS device over 4 weeks improved attention in adult patients with ADHD who were not taking stimulant medication. Home-based tDCS could be a nonpharmacological alternative for patients with ADHD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04003740.

Neurotherapeutics for ADHD: Do they work?

This paper reflects on the use of neurotherapeutics for attention-deficit/hyperactivity disorder (ADHD). ADHD is the most imaged child psychiatric disorder, with over 3 decades of magnetic resonance imaging (MRI) research. Findings are relatively homogeneous compared to other psychiatric conditions with consistent evidence for differences, albeit small, relative to healthy controls in the structure and function of several frontal, parietotemporal, and striatal brain regions as well as their inter-regional structural and functional connections. The functional deficits have been targeted with modern neurotherapeutics, including neurofeedback (using most commonly electroencephalography and more recently functional near-infrared spectroscopy and functional MRI) and non-invasive brain stimulation (such as repetitive transcranial magnetic stimulation, transcranial direct current stimulation, or external trigeminal nerve stimulation). Except for electroencephalography-neurofeedback, the majority of neurotherapeutic studies have been relatively small, with very heterogenous research protocols and outcome measures and-likely as a consequence-inconsistent findings. Furthermore, most brain stimulation studies have tested effects on cognitive functions rather than clinical symptoms. So far, findings have not been very promising. Future studies require systematic testing of optimal protocols in large samples or homogenous subgroups to understand response prediction that could lead to individualized treatment.

Results of Neurofeedback in Treatment of Children with ADHD: A Systematic Review of Randomized Controlled Trials

Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent disorders in children and adolescents. Neurofeedback, a nonpharmaceutical treatment, has shown promising results. To review the evidence of efficacy of neurofeedback as a treatment for children and adolescents with ADHD. A systematic review of the specific scientific studies published in 1995-2021, identifying and analyzing randomized controlled trials (RCT). A total of 1636 articles were identified and 165 met inclusion criteria, of which 67 were RCTs. Neurofeedback training was associated with significant long-term reduction in symptoms of ADHD. Though limitations exist regarding conclusions about the specific effects of neurofeedback, the review documents improvements in school, social, and family environments.