Pathophysiology of ADHD and associated problems-starting points for NF interventions?

Recent developments in intranasal drug delivery of nanomedicines for the treatment of neuropsychiatric disorders

Neuropsychiatric disorders are multifaceted syndromes with confounding neurological explanations. It includes anxiety, depression, autism spectrum disorder, attention deficit hyperactivity disorder, schizophrenia, Tourette's syndrome, delirium, dementia, vascular cognitive impairment, and apathy etc. Globally, these disorders occupy 15% of all diseases. As per the WHO, India has one of the largest populations of people with mental illnesses worldwide. The blood-brain barrier (BBB) makes it extremely difficult to distribute medicine to target cells in the brain tissues. However, it is possible through novel advancements in nanotechnology, molecular biology, and neurosciences. One such cutting-edge delivery method, nose-to-brain (N2B) drug delivery using nanoformulation (NF), overcomes traditional drug formulation and delivery limitations. Later offers more controlled drug release, better bioavailability, improved patient acceptance, reduced biological interference, and circumvention of BBB. When medicines are delivered via the intranasal (IN) route, they enter the nasal cavity and go to the brain via connections between the olfactory and trigeminal nerves and the nasal mucosa in N2B. Delivering phytochemical, bioactive and synthetic NF is being investigated with the N2B delivery strategy. The mucociliary clearance, enzyme degradation, and drug translocations by efflux mechanisms are significant issues associated with N2B delivery. This review article discusses the types of neuropsychiatric disorders and their treatment with plant-derived as well as synthetic drug-loaded NFs administered via the IN-delivery system. In conclusion, this review provided a comprehensive and critical overview of the IN applicability of plant-derived NFs for psychiatric disorders.

Machine learning-enabled detection of attention-deficit/hyperactivity disorder with multimodal physiological data: a case-control study

BACKGROUND

Attention-Deficit/Hyperactivity Disorder (ADHD) is a multifaceted neurodevelopmental psychiatric condition that typically emerges during childhood but often persists into adulthood, significantly impacting individuals' functioning, relationships, productivity, and overall quality of life. However, the current diagnostic process exhibits limitations that can significantly affect its overall effectiveness. Notably, its face-to-face and time-consuming nature, coupled with the reliance on subjective recall of historical information and clinician subjectivity, stand out as key challenges. To address these limitations, objective measures such as neuropsychological evaluations, imaging techniques and physiological monitoring of the Autonomic Nervous System functioning, have been explored.

METHODS

The main aim of this study was to investigate whether physiological data (i.e., Electrodermal Activity, Heart Rate Variability, and Skin Temperature) can serve as meaningful indicators of ADHD, evaluating its utility in distinguishing adult ADHD patients. This observational, case-control study included a total of 76 adult participants (32 ADHD patients and 44 healthy controls) who underwent a series of Stroop tests, while their physiological data was passively collected using a multi-sensor wearable device. Univariate feature analysis was employed to identify the tests that triggered significant signal responses, while the Informative k-Nearest Neighbors (KNN) algorithm was used to filter out less informative data points. Finally, a machine-learning decision pipeline incorporating various classification algorithms, including Logistic Regression, KNN, Random Forests, and Support Vector Machines (SVM), was utilized for ADHD patient detection.

RESULTS

Results indicate that the SVM-based model yielded the optimal performance, achieving 81.6% accuracy, maintaining a balance between the experimental and control groups, with sensitivity and specificity of 81.4% and 81.9%, respectively. Additionally, integration of data from all physiological signals yielded the best results, suggesting that each modality captures unique aspects of ADHD.

CONCLUSIONS

This study underscores the potential of physiological signals as valuable diagnostic indicators of adult ADHD. For the first time, to the best of our knowledge, our findings demonstrate that multimodal physiological data collected via wearable devices can complement traditional diagnostic approaches. Further research is warranted to explore the clinical applications and long-term implications of utilizing physiological markers in ADHD diagnosis and management.

Pediatric Pharmacology for the Primary Care Provider: Advances and Limitations

Despite >1 in 5 children taking prescription drugs in the United States, off-label drug use is common. To increase the study of drugs in children, regulatory bodies have enacted legislation to incentivize and require pediatric drug studies. As a result of this legislation, novel trial approaches, and an increase in personnel with pediatric expertise, there have been numerous advancements in pediatric drug development. With this review, we aim to highlight developments in pediatric pharmacology over the past 6 years for the most common disease processes that may be treated pharmacologically by the pediatric primary care provider. Using information extracted from label changes between 2018 and 2023, the published literature, and Clinicaltrials.gov, we discuss advances across multiple therapeutic areas relevant to the pediatric primary care provider, including asthma, obesity and related disorders, mental health disorders, infections, and dermatologic conditions. We highlight instances in which new drugs have been developed on the basis of a deeper mechanistic understanding of illness and instances in which labels have been expanded in older drugs on the basis of newly available data. We then consider additional factors that affect pediatric drug use, including cost and nonpharmacologic therapies. Although there is work to be done, efforts focused on pediatric-specific drug development will increase the availability of evidence-based, labeled guidance for commonly prescribed drugs and improve outcomes through the safe and effective use of drugs in children.

Effects of game-based digital therapeutics on attention deficit hyperactivity disorder in children and adolescents as assessed by parents or teachers: a systematic review and meta-analysis

Attention-deficit/hyperactivity disorder (ADHD) is a childhood-onset disorder characterized by pharmacological and non-pharmacological interventions. Despite the available treatment options and prevention measures, conventional treatments have several limitations. Digital therapeutics (DTx) like EndeavorRx® is an emerging alternative to overcome these limitations. EndeavorRx® is the first FDA-approved, game-based DTx approved for the treatment of pediatric ADHD. We investigated the effects of game-based DTx in randomised controlled trials (RCTs) on children and adolescents with ADHD. In this systematic review and meta-analysis, we searched PubMed, Embase, and PsycINFO databases up to January 2022. The protocol was registered (CRD42022299866). The assessor was defined as parents and teachers. The primary outcome was differences in inattention reported by the assessor, and the secondary outcome was differences in hyperactivity and hyperactivity/impulsivity reported by the assessor and the relative comparisons between game-based DTx, medicine, and control with indirect meta-analysis. Game-based DTx improved inattention more than the control upon assessment by assessors (standard mean difference (SMD) 0.28, 95% confidence interval (CI) 0.14-0.41; SMD 0.21, 95% CI 0.03-0.39, respectively), while medication improved inattention more than game-based DTx (SMD - 0·62, 95% CI - 1·04 to - 0·20) upon assessment by the teacher. Game-based DTx improved hyperactivity/impulsivity than the control upon assessment by assessors (SMD 0.28, 95% CI 0.03-0.53; SMD 0.30, 95% CI 0.05-0.55, respectively), and medication improved hyperactivity/impulsivity significantly than game-based DTx upon assessment by the teacher. Hyperactivity has not been reported extensively. As a result, game-based DTx had a more significant effect than the control, however medication was more effective.

Risky driving behavior among individuals with Autism, ADHD, and typically developing persons

INTRODUCTION

Many individuals with Autism Spectrum Disorder (ASD) and Attention Deficit Hyperactivity Disorder (ADHD) often experience difficulty with driving, including difficulty with obtaining a driver's license as well as driving safely and efficiently. Such difficulties negatively impact their ability to function independently and participate in daily activities that require driving. ASD and ADHD commonly occur co-morbidly and share many overlapping clinical features. Few studies have directly compared the nature of difficulties in driving safety outcomes between ASD and ADHD. The overarching goal of the current study was to characterize and compare self-reported driving behavior among young autistic drivers, ADHD drivers, and typically developing (TD) drivers.

METHOD

Fifty-four participants (14 ASD, 20 ADHD, 20 TD); ages 16-30) completed the Autism Spectrum Quotient and ADHD Adult Rating scale as a method of screening of symptoms. All three groups then completed the Driving Behavior Questionnaire (DBQ), which measured self-reported driving violations, driving errors, and overall risky driving behavior. The three groups of ASD, ADHD, and TD individuals were then compared regarding symptomology and driving behavior differences.

RESULTS

One-way ANOVAs indicated group differences in DBQ total scores and DBQ errors. Drivers with ADHD reported significantly greater overall risky driving behaviors and driving errors compared to ASD and TD drivers. There were no significant differences between ASD and TD drivers in reported risky driving behaviors and errors. Linear regressions indicated that among all drivers, self-reported ADHD symptoms were significantly associated with higher levels of self-reported overall risky driving and driving errors, regardless of diagnostic group.

DISCUSSION

Risky driving and driving errors may be more closely related to symptoms that are characteristic of ADHD. This has implications for individuals with ADHD and autistic individuals who often show or report higher rates of ADHD symptoms. Future studies should compare driving skills of ASD and ADHD drivers using objective measures of driving performance, such as driving simulators or on-road tests.

P2X4 signalling contributes to hyperactivity but not pain sensitization comorbidity in a mouse model of attention deficit/hyperactivity disorder

Introduction: Attention deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by hyperactivity, inattention, and impulsivity that often persist until adulthood. Frequent comorbid disorders accompany ADHD and two thirds of children diagnosed with ADHD also suffer from behavioural disorders and from alteration of sensory processing. We recently characterized the comorbidity between ADHD-like symptoms and pain sensitisation in a pharmacological mouse model of ADHD, and we demonstrated the implication of the anterior cingulate cortex and posterior insula. However, few studies have explored the causal mechanisms underlying the interactions between ADHD and pain. The implication of inflammatory mechanisms has been suggested but the signalling pathways involved have not been explored. Methods: We investigated the roles of purinergic signalling, at the crossroad of pain and neuroinflammatory pathways, by using a transgenic mouse line that carries a total deletion of the P2X4 receptor. Results: We demonstrated that P2X4 deletion prevents hyperactivity in the mouse model of ADHD. In contrast, the absence of P2X4 lowered thermal pain thresholds in sham conditions and did not affect pain sensitization in ADHD-like conditions. We further analysed microglia reactivity and the expression of inflammatory markers in wild type and P2X4KO mice. Our results revealed that P2X4 deletion limits microglia reactivity but at the same time exerts proinflammatory effects in the anterior cingulate cortex and posterior insula. Conclusion: This dual role of P2X4 could be responsible for the differential effects noted on ADHD-like symptoms and pain sensitization and calls for further studies to investigate the therapeutic benefit of targeting the P2X4 receptor in ADHD patients.

Transcranial Direct Current Stimulation as an Approach to Mitigate Neurodevelopmental Disorders Affecting Excitation/Inhibition Balance: Focus on Autism Spectrum Disorder, Schizophrenia, and Attention Deficit/Hyperactivity Disorder

Transcranial direct current stimulation (tDCS) has been proposed as a promising therapy for rehabilitation of neurodevelopmental disorders. In this review, we discuss studies on the impact of tDCS as a therapy for autism, schizophrenia, and attention deficit/hyperactivity disorder, as well as the tDCS' mechanism of action, and propose future paths of research to optimize tDCS treatment protocols. The mechanism underlying tDCS effects is the modulation of excitatory and/or inhibitory activity, making it a valuable tool for restoring the excitation/inhibition (E/I) balance which is disrupted in many neurodevelopmental disorders. Clinical studies have shown that tDCS therapy is well-tolerated by patients and seems to ameliorate behavior and cognitive functions. Alterations in early development of neuronal circuits lead to disruptions in brain activity in neurodevelopmental disorders. An increasing amount of research into the effects of tDCS on neuronal activity has provided a foundation for its use as a therapy for behavior and cognitive characteristics of neurodevelopmental disorders. Clinical studies show that tDCS appears to ameliorate behavioral and cognitive outcomes of patients with autism, schizophrenia, and attention deficit/hyperactivity disorder. More research is needed to understand the mechanisms of action of tDCS and to optimize treatment protocols.

Tetrahydrobiopterin and Its Multiple Roles in Neuropsychological Disorders

Tetrahydrobiopterin (BH4) is a multifunctional co-factor of various enzymes and a substantial amount of studies have shown BH4 as a key regulator in the synthesis of neurotransmitters such as serotonin, nor-epinephrine as well as dopamine. The imbalance of BH4 may affect neurotransmitter production which can lead to many abnormalities in CNS. This article reviews the role of BH4 in neurodegenerative and neurodevelopmental disorders. We focus on the therapeutic potential of BH4 in various brain diseases that involves neurotransmitters and attempt to address how the modulation of BH4 may provide a novel strategy in various neuropsychological conditions.

A randomized controlled study of remote computerized cognitive, neurofeedback, and combined training in the treatment of children with attention-deficit/hyperactivity disorder

There is an increasing interest in non-pharmacological treatments for children with attention-deficit/hyperactivity disorder (AD/HD), especially digital techniques that can be remotely delivered, such as neurofeedback (NFT) and computerized cognitive training (CCT). In this study, a randomized controlled design was used to compare training outcomes between remotely delivered NFT, CCT, and combined NFT/CCT training approaches. A total of 121 children with AD/HD were randomly assigned to the NFT, CCT, or NFT/CCT training groups, with 80 children completing the training program. Pre- and post-training symptoms (primary outcome), executive and daily functions were measured using questionnaires as well as resting EEG during eyes-closed (EC) and eyes-open (EO) conditions. After 3 months of training, the inattentive and hyperactive/impulsive symptoms, inhibition, working memory, learning and life skills of the three groups of children were significantly improved. The objective EEG activity showed a consistent increase in the relative alpha power in the EO condition among the three training groups. Training differences were not observed between groups. There was a positive correlation between pre-training EO relative alpha power and symptom improvement scores of inattention and hyperactivity/impulsivity, as well as a negative correlation between pre-training inattention scores and change in EO relative alpha. This study verified the training effects of NFT, CCT, and combined NFT/CCT training in children with AD/HD and revealed an objective therapeutic role for individual relative alpha activity. The verified feasibility and effectiveness of home-based digital training support promotion and application of digital remote training.

Self-management training vs. neurofeedback interventions for attention deficit hyperactivity disorder: Results of a randomized controlled treatment study

OBJECTIVES

Neurofeedback (NF) and self-management training (SMT) may be viable treatment options for patients with attention deficit hyperactivity disorder (ADHD) if they alleviate core symptoms, enhance the patients' self-concept and improve their quality of life (QoL). Aim of the current study is evaluating both interventions accordingly and to test whether specific improvements in core symptoms lead to more general improvements in self-concept and QoL.

METHODS

In a psychotherapeutic outpatient clinic in Germany, a total of N = 139 children with ADHD were screened for eligibility, of which 111 fulfilled inclusion criteria and participated in the study in accordance with the CONSORT 2010 statement. These were randomly assigned to NF vs. SMT interventions. Changes from pre- to post-intervention in core ADHD symptoms relying on parent and teacher reports (CONNERS 3) and objective tests (Qb-Test) as well as self-concept (interview with the children) and QoL assessments (using the KINDL-R self-report) were compared between patients receiving NF or SMT.

RESULTS

Significant improvements in ADHD symptoms were achieved similarly in both treatment groups, whilst QoL and self-concept improved after SMT only.

CONCLUSION

This treatment study provides further evidence that SMT and NF may reduce core symptoms, but SMT may also improve patients' self-concept and QoL and may thus in its current form be the favorable treatment option in naturalistic settings. However, several limitations of the current study implicate that further research is required before definitive conclusions and recommendations for clinical practice can be given.

CLINICAL TRIAL REGISTRATION

[www.clinicaltrials.gov], identifier [NCT01879644].

Effects of Iron Supplementation on Attention Deficit Hyperactivity Disorder in Children Treated with Methylphenidate

Objective

To evaluate the effect of iron on the attention deficit hyperactivity disorder, treated with methylphenidate.

Methods

This double-blind, randomized placebo-controlled clinical trial was performed on 50 children with attention deficit hyperactivity disorder under the treatment of methylphenidate, with ferritin levels below 30 ng/ml and absence of anemia. They were randomly assigned into two groups of ferrous sulfate and placebo, for 12 weeks. Conners' Parent Rating Scale (CPRS) was used to assess the outcome in the first, sixth, and twelfth weeks.

Results

Almost all CPRS subscales improved in the ferrous sulfate group from the baseline to the endpoint, although only the changes in conduct subscale scores were significant (p = 0.003). There was no significant difference in score changes between two groups in intergroup comparison. Also, the score of learning problems (p = 0.007) in the first six weeks, and conduct (p = 0.023) and psychosomatic (p = 0.018) subscales in the second six weeks were improved in the ferrous sulfate group compared with the placebo group.

Conclusion

Our study showed promising effects of iron supplementation in the improvement of subscales of the CPRS.

Animal models of attention-deficit hyperactivity disorder (ADHD)

Attention-deficit hyperactivity disorder (ADHD) is a heterogeneous neuropsychiatric disorder characterized by three primary symptoms hyperactivity, attention deficit, and impulsiveness, observed in both children and adults. In childhood, this disorder is more common in boys than in girls, and at least 75% will continue to suffer from the disorder until adulthood. Individuals with ADHD generally have poor academic, occupational, and social functioning resulting from developmentally inappropriate levels of hyperactivity and impulsivity, as well as impaired ability to maintain attention on motivationally relevant tasks. Very few drugs available in clinical practice altogether abolish the symptoms of ADHD, therefore, to find new drugs and target it is essential to understand the neuropathological, neurochemical, and genetic alterations that lead to the progression of ADHD. With this contrast, an animal study is the best approach because animal models provide relatively fast invasive manipulation, rigorous hypothesis testing, as well as it provides a better angle to understand the pathological mechanisms involved in disease progression. Moreover, animal models, especially for ADHD, serve with good predictive validity would allow the assessment and development of new therapeutic interventions, with this aim, the present review collect the various animal models on a single platform so that the research can select an appropriate model to pursue his study.

Electrophysiology Echoes Brain Dynamics in Children and Adolescents With Tourette Syndrome-A Developmental Perspective

The development of the complex clinical picture of motor and vocal tics in children and adolescents with Tourette syndrome (TS) must be paralleled by changes in the underlying pathophysiology. Electrophysiological methods such as EEG and event-related potentials (ERPs) are non-invasive, safe and easy to apply and thus seem to provide an adequate means to investigate brain dynamics during this brain maturational period. Also, electrophysiology is characterized by a high time resolution and can reflect motor, sensory and cognitive aspects as well as sleep behavior. Hence, this narrative review focuses on how electrophysiology echoes brain dynamics during development of youngsters with TS and might be useful for the treatment of tics. A comprehensive picture of developmental brain dynamics could be revealed showing that electrophysiological parameters evolve concurrently with clinical characteristics of TS. Specifically, evidence for a maturational delay of motor inhibition related to cortico-spinal hyper-excitability and brain mechanisms for its cognitive compensation could be shown. Moreover, deviant sleep parameters and probably a stronger perception-action binding were reported. For neuromodulatory treatments (e.g., neurofeedback; repetitive transcranial magnetic stimulation, rTMS/transcranial direct current stimulation, tDCS) targeting neuronal deficits and/or strengthening compensatory brain mechanisms, pilot studies support the possibility of positive effects regarding tic reduction. Finally, attention-deficit/hyperactivity disorder (ADHD), as a highly frequent co-existing disorder with TS, has to be considered when using and interpreting electrophysiological measures in TS. In conclusion, application of electrophysiology seems to be promising regarding clinical and research aspects in youngsters with TS.

Predictors of neurofeedback training outcome: A systematic review

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Best available evidence exists for neurophysiological baseline parameters.

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No substantial effect of age and intelligence on training outcome in most cases.

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Neurofeedback learning success predicts treatment outcome.

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To date, a reliable selection of participants based on predictors is not possible.

Neurofeedback (NF), a training tool aimed at enhancing neural self-regulation, has been suggested as a complementary treatment option for neuropsychiatric disorders. Despite its potential as a neurobiological intervention directly targeting neural alterations underlying clinical symptoms, the efficacy of NF for the treatment of mental disorders has been questioned recently by negative findings obtained in randomized controlled trials (e.g., Cortese et al., 2016). A possible reason for insufficient group effects of NF trainings vs. placebo could be related to the high rate of participants who fail to self-regulate brain activity by NF (“non-learners”). Another reason could be the application of standardized NF protocols not adjusted to individual differences in pathophysiology. Against this background, we have summarized information on factors determining training and treatment success to provide a basis for the development of individualized training protocols and/or clinical indications.

The present systematic review included 25 reports investigating predictors for the outcome of NF trainings in healthy individuals as well as patients affected by mental disorders or epilepsy. We selected these studies based on searches in EBSCOhost using combinations of the keywords “neurofeedback” and “predictor/predictors”. As “NF training” we defined all NF applications with at least two sessions.

The best available evidence exists for neurophysiological baseline parameters. Among them, the target parameters of the respective training seem to be of particular importance. However, particularities of the different experimental designs and outcome criteria restrict the interpretability of some of the information we extracted. Therefore, further research is needed to gain more profound knowledge about predictors of NF outcome.

Incremental benefits of EEG informed fMRI in the study of disorders related to meso-corticolimbic dopamine pathway dysfunction: A systematic review of recent literature

Functional magnetic resonance imaging (fMRI) is a non-invasive imaging modality that enables the assessment of neural connectivity and oxygen utility of the brain using blood oxygen level dependent (BOLD) imaging sequence. Electroencephalography (EEG), on the other hands, looks at cortical electrical impulses of the brain thus detecting brainwave patterns during rest and thought processing. The combination of these two modalities is called fMRI with simultaneous EEG (fMRI-EEG), which has emerged as a new tool for experimental neuroscience assessments and has been applied clinically in many settings, most commonly in epilepsy cases. Recent advances in imaging has led to fMRI-EEG being utilized in behavioural studies which can help in giving an objective assessment of ambiguous cases and help in the assessment of response to treatment by providing a non-invasive biomarker of the disease processes. We aim to review the role and interpretation of fMRI-EEG in studies pertaining to psychiatric disorders and behavioral abnormalities.

Attention-Deficit/Hyperactivity Disorder (ADHD) and Emotion Regulation Over the Life Span

PURPOSE OF REVIEW

Emotional symptoms are common and persistent in youth and adults with attention-deficit/hyperactivity disorder (ADHD) and cause clinically significant impairments. We review recent neuropsychological, neurophysiological, and peripheral psychophysiological evidence for emotion and emotion regulation deficits in ADHD across youth and adults.

RECENT FINDINGS

Central and autonomous nervous system correlates argue in favor of more general self-regulation deficits and also specific emotional deficits in ADHD. These include general performance deficits in executive functions, and structural as well as functional impairments in neuronal networks associated with top-down self-regulation. Specific deficits with bottom-up emotional activation in the amygdala and emotion evaluation associated with the orbitofrontal cortex have also been described. Furthermore, vagally mediated, high-frequency heart rate variability is associated with emotional self-regulation deficits throughout the life span. The current evidence is based on multilevel studies that assess associations of emotion regulation. However, further studies that adequately consider the processual recursive character of emotion generation and regulation may give important new insights into emotional regulation of ADHD. Emotion regulation deficits in ADHD are associated with specific as well as general self-regulation deficits traceable on the level of neuropsychological, neurophysiological, and psychophysiological assessments. The temporal dynamics of the interplay of those different systems need further study in order to optimize and personalize treatment of emotion regulation difficulties, including emotional reactivity, in patients with ADHD.

A novel training-free externally-regulated neurofeedback (ER-NF) system using phase-guided visual stimulation for alpha modulation

The efficacy of neurofeedback is a point of great controversy, because a certain proportion of users cannot properly regulate their brain activities and thereby fail to benefit from neurofeedback. To address the neurofeedback inefficacy problem, the present study is aimed to design and implement a new neurofeedback system that can more effectively and consistently regulate users' brain activities than the conventional way of training users to voluntarily regulate brain activities. The new neurofeedback system delivers external visual stimuli continuously at a specific alpha phase, which is real-time decoded from ongoing alpha wave, to regulate the alpha wave. Experimental results show that the proposed training-free externally-regulated neurofeedback (ER-NF) system can achieve consistent (effective in almost all sessions for almost all users), flexible (either increasing or decreasing peak alpha frequency and alpha power), and immediate (taking or losing effect immediately after stimulation is on or off) modulation effects on alpha wave. Therefore, the ER-NF system holds great potential to be able to more reliably and flexibly modulate cognition and behavior.

Attention Deficit Hyperactivity Disorder in Preschool-Age Children

Attention deficit hyperactivity disorder is a neurodevelopmental disorder marked by age-inappropriate deficits in attention or hyperactivity/impulsivity that interfere with functioning or development. It is highly correlated with other disorders, such as oppositional defiant disorder, conduct disorder, and mood symptoms. The etiology is multifactorial, and neuroimaging findings are nonspecific. Although assessment tools exist, there is variability among them, and historically, parent-teacher agreement has not been consistent. Treatment algorithm for attention deficit hyperactivity disorder in preschoolers includes behavioral interventions first followed by psychopharmacologic treatment when behavioral therapies fail. Other nonpharmacologic and nonbehavioral interventions are discussed including the role of exercise and nutrition.

Perception in attention deficit hyperactivity disorder

A large body of research demonstrated that individuals with attention deficit hyperactivity disorder (ADHD) suffer from various neuropsychological deficits. In contrast, less is known and only divergent evidence exists on perceptual functions of individuals with ADHD. This is problematic as neuropsychological and perceptual functions are closely interrelated and are often difficult to disentangle in behavioral assessments. This study presents the conduct and results of a systematic literature review on perceptual functions in children and adults with ADHD. This review considers studies using psychophysical methods (objective measurements) and self- and informant reports (subjective measurements). Results indicate that individuals with ADHD have altered perceptual functions in various domains as compared to typically developing individuals. Increased perceptual functions in individuals with ADHD were found with regard to olfactory detection thresholds, whereas reduced perceptual functions were evident for aspects of visual and speech perception. Moreover, individuals with ADHD were found to experience discomfort to sensory stimuli at a lower level than typically developing individuals. Alterations of perceptual functions in individuals with ADHD were shown to be moderated by various factors, such as pharmacological treatment, cognitive functions, and symptom severity. We conclude by giving implications for daily life functioning and clinical practice.

Game-based combined cognitive and neurofeedback training using Focus Pocus reduces symptom severity in children with diagnosed AD/HD and subclinical AD/HD

Previous studies report reductions in symptom severity after combined working memory (WM) and inhibitory control (IC) training in children with AD/HD. Based on theoretical accounts of the role of arousal/attention modulation problems in AD/HD, the current study examined the efficacy of combined WM, IC, and neurofeedback training in children with AD/HD and subclinical AD/HD. Using a randomized waitlist control design, 85 children were randomly allocated to a training or waitlist condition and completed pre- and post-training assessments of overt behavior, trained and untrained cognitive task performance, and resting and task-related EEG activity. The training group completed twenty-five sessions of training using Focus Pocus software at home over a 7 to 8-week period. Trainees improved at the trained tasks, while enjoyment and engagement declined across sessions. After training, AD/HD symptom severity was reduced in the AD/HD and subclinical groups according to parents, and in the former group only according to blinded teachers and significant-others. There were minor improvements in two of six near-transfer tasks, and evidence of far-transfer of training effects in four of five far-transfer tasks. Frontal region changes indicated normalization of atypical EEG features with reduced delta and increased alpha activity. It is concluded that technology developments provide an interesting a vehicle for delivering interventions and that, while further research is needed, combined WM, IC, and neurofeedback training can reduce AD/HD symptom severity in children with AD/HD and may also be beneficial to children with subclinical AD/HD.

NIRS-based neurofeedback training in a virtual reality classroom for children with attention-deficit/hyperactivity disorder: study protocol for a randomized controlled trial

Background

Children with attention-deficit/hyperactivity disorder (ADHD) suffer from attention deficits, motor hyperactivity, and impulsive behaviour. These impairments are experienced at home, at school, and with friends. Functional imaging studies show that ADHD behaviour and impairments in executive functions (EFs) are mirrored by aberrant neurophysiological functioning. Moreover, several studies show that ADHD behaviour, impairments in EFs, and a lack of self-control contribute to poor school performance. Non-pharmacological interventions such as neurofeedback training (NFT), for instance, aim at improving neurophysiological and neuropsychological functioning as well as behaviour. Consequently, NFT is expected to improve school performance, EFs, and self-control in children with ADHD. Generalization of acquired self-regulation skills from laboratory to real life is crucial for a transfer to everyday situations and is hypothesized to be facilitated via training using virtual reality (VR) environments. Consequently, experiencing NFT in VR is expected to yield greater effects than training in two dimensions (2D).

Methods/design

Ninety children with a clinical diagnosis of ADHD will be included in the study. Participants may be medicated or unmedicated. After random assignation to one of three conditions, all participants receive 15 training sessions of either near-infrared spectroscopy (NIRS)-based NFT in VR, NIRS-based NFT in 2D, or electromyogram-based biofeedback training in VR. ADHD symptoms, self-control, EF, health-related quality of life, school performance, and motor activity measured via parent, teacher, and child reports or objectively will be assessed before and after the intervention and at a 6 months follow-up. Furthermore, we are interested in parents’ expectations about the training’s effects.

Discussion

This is, to our knowledge, the first study investigating the efficacy of NFT for children with ADHD in a VR compared to a 2D environment. Furthermore, this study will contribute to the discussion about the efficacy and specific and unspecific effects of NFTs in children with ADHD. In addition to commonly assessed variables such as ADHD symptoms, NIRS and behavioural data obtained in EF measures, health-related quality of life, and parents’ expectations about the intervention’s effects, this study will investigate the effects on self-control, school performance, and motor activity.

Trial registration

ClinicalTrials.gov, NCT02572180. Registered on 19 November 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1769-3) contains supplementary material, which is available to authorized users.

Prenatal Alcohol Exposure in Rodents As a Promising Model for the Study of ADHD Molecular Basis

A physiological parallelism, or even a causal effect relationship, can be deducted from the analysis of the main characteristics of the “Alcohol Related Neurodevelopmental Disorders” (ARND), derived from prenatal alcohol exposure (PAE), and the behavioral performance in the Attention-deficit/hyperactivity disorder (ADHD). These two clinically distinct disease entities, exhibits many common features. They affect neurological shared pathways, and also related neurotransmitter systems. We briefly review here these parallelisms, with their common and uncommon characteristics, and with an emphasis in the subjacent molecular mechanisms of the behavioral manifestations, that lead us to propose that PAE in rats can be considered as a suitable model for the study of ADHD.