Do cognitive interventions for preschoolers improve executive functions and reduce ADHD and externalizing symptoms? A meta-analysis of randomized controlled trials

A 5-week Digital Intervention to Reduce Attention Problems in Children With ADHD: A Double-Blind Randomized Controlled Trial

OBJECTIVE

Growing evidence suggests digital interventions may provide neurocognitive benefits for children with ADHD. This study aimed to investigate the efficacy of a digital attention intervention in children with ADHD.

METHOD

In this double-blind randomized controlled trial 55 children with ADHD (5-9 years) were allocated to the intervention (N = 28) or control program (N = 27). Both programs were delivered via touchscreen tablets at home 5 days a week for 5 weeks. The primary outcome was change in the Test of Variables of Attention (TOVA) Attention Comparison Score (ACS) from pre- to post-intervention.

RESULTS

Participants who received the intervention had significantly greater improvements in the TOVA ACS from pre- to post-intervention than those in the control (p < .044). No intervention effects were observed on secondary outcomes assessing executive functioning, ADHD symptoms, or functional impairment.

CONCLUSION

Collectively these findings provide insufficient evidence for the implementation of digital attention interventions for children with ADHD.

From Consensus Statement to Pills to Pixels: New Innovations in Attention-Deficit/Hyperactivity Disorder Care

Objectives: This review aims to present recent innovations and advancements in attention-deficit/hyperactivity disorder (ADHD) care, encompassing international consensus statement, new medication formulations, digital therapeutics, and neurostimulation devices. Methods: A comprehensive literature search of relevant articles published in the past five years was conducted, emphasizing the evidence base, efficacy, safety, and practical implications of these advancements. Results: The World Federation of ADHD Consensus Statement offers an updated diagnostic and treatment framework rooted in global scientific evidence. There are several newer ADHD medication formulations, including a nonstimulant (Viloxazine extended release) and the first transdermal amphetamine patch approved to treat ADHD. These options offer some unique benefits to personalize treatment based on symptom profile, lifestyle, preferences, and response. Digital tools offer additional means to restructure environments for individuals with ADHD, reducing impairment and reliance on others. In addition, digital therapeutics enhance access, affordability, personalization, and feasibility of ADHD care, complementing or augmenting existing interventions. Trigeminal nerve stimulation emerges as a well-tolerated nonpharmacological, device-based treatment for pediatric ADHD, with initial trials indicating effect sizes comparable to nonstimulant medications. Conclusions: These innovations in ADHD care represent clinically significant new treatment options and opportunities for personalized care. Health care professionals should integrate these developments into clinical practice, mindful of individual patient and family needs and preferences. Future research should assess long-term outcomes, cost-effectiveness, and acceptability of these innovations.

Disentangling the relationships between motor control and cognitive control in young children with symptoms of ADHD

Children with ADHD experience difficulties with motor and cognitive control. However, the relationships between these symptoms are poorly understood. As a step toward improving treatment, this study investigated associations between specific aspects of motor control and cognitive control in children with varying levels of hyperactive-impulsive symptoms. A heterogeneous sample of 255 children of 4 to 10 years of age (median = 6.50, MAD = 1.36) completed a battery of tests probing motor generation, visuomotor fluency, visuomotor flexibility, cognitive inhibition, verbal and visuospatial working memory, and cognitive flexibility. Their caregivers were interviewed regarding their hyperactive-impulsive symptoms. 25.9% of the main sample met diagnostic criteria for ADHD. Multiple linear regression analysis was used to determine whether specific aspects of motor control were associated with specific aspects of cognitive control, and whether any associations were moderated by hyperactive-impulsive symptoms. Additionally, cognitive modeling (the drift diffusion model approximated with EZ-DM) was used to understand performance on a cognitive inhibition task. Visuomotor fluency was significantly associated with cognitive inhibition. Visuomotor flexibility was significantly associated with cognitive flexibility. There were no significant moderation effects. Cognitive modeling was inconclusive. In conclusion, the ability to fluently perform visually guided continuous movement is linked with the ability to inhibit the effects of distracting information. The ability to spontaneously use visual information to flexibly alter motor responses is related to the ability to cognitively shift from one frame of mind to another. These relationships appear to be quantitatively and qualitatively similar across the childhood hyperactive-impulsive continuum as rated by parents.

A systematic meta-review of systematic reviews on attention deficit hyperactivity disorder

BACKGROUND

There are now hundreds of systematic reviews on attention deficit hyperactivity disorder (ADHD) of variable quality. To help navigate this literature, we have reviewed systematic reviews on any topic on ADHD.

METHODS

We searched MEDLINE, PubMed, PsycINFO, Cochrane Library, and Web of Science and performed quality assessment according to the Joanna Briggs Institute Manual for Evidence Synthesis. A total of 231 systematic reviews and meta-analyses met the eligibility criteria.

RESULTS

The prevalence of ADHD was 7.2% for children and adolescents and 2.5% for adults, though with major uncertainty due to methodological variation in the existing literature. There is evidence for both biological and social risk factors for ADHD, but this evidence is mostly correlational rather than causal due to confounding and reverse causality. There is strong evidence for the efficacy of pharmacological treatment on symptom reduction in the short-term, particularly for stimulants. However, there is limited evidence for the efficacy of pharmacotherapy in mitigating adverse life trajectories such as educational attainment, employment, substance abuse, injuries, suicides, crime, and comorbid mental and somatic conditions. Pharmacotherapy is linked with side effects like disturbed sleep, reduced appetite, and increased blood pressure, but less is known about potential adverse effects after long-term use. Evidence of the efficacy of nonpharmacological treatments is mixed.

CONCLUSIONS

Despite hundreds of systematic reviews on ADHD, key questions are still unanswered. Evidence gaps remain as to a more accurate prevalence of ADHD, whether documented risk factors are causal, the efficacy of nonpharmacological treatments on any outcomes, and pharmacotherapy in mitigating the adverse outcomes associated with ADHD.

Effect of Cognitive Training Programs Based on Computer Systems on Executive Functions in Children With ADHD: A Systematic Review

BACKGROUND

The purpose of this systematic review is to synthesize the existing literature reporting the effects of computerized cognitive trainings on the executive functions of children with ADHD.

METHOD

A systematic review was carried out following the PRISMA statement; the primary sources used were five electronic databases (Scopus, Science Direct, Pubmed, Springer, Taylor & Francis).

RESULTS

20 articles met the eligibility criteria, data on the training characteristics and the effects on executive functions were extracted, followed by an analysis of bias and the methodological quality of the studies. The results of the studies were widely heterogeneous, largely associated with the variety of training programs and the measurement instruments used. The most studied executive functions were working memory and inhibitory control. Some of the studies reported that the intervention led to significant effects on working memory and attention (N = 7), and improvements in inhibitory control (N = 5) and planning (N = 4) were also reported. At the same time, others did not report the effects of the intervention on these processes. The assessment of the quality of the evidence showed important risk biases among the reviewed studies.

CONCLUSION

Some training based on computer systems showed positive effects on the executive functions of working memory, attention, and inhibitory control in children with ADHD. However, other training sessions did not show significant effects. In general, the evidence shows mixed results, a high diversity of measurement instruments, and high risks of bias between the studies. Therefore, the evidence has not been consistent about the general benefits of computerized training on the executive functions of children with ADHD.

Effectiveness of ENGAGE in reducing difficulties in everyday executive functions among Finnish preschoolers: a randomized controlled trial

Effective interventions applicable for young preschool-age children are needed to reduce the risk of widespread and sustained adversities that are linked to early executive function (EF) difficulties. This randomized controlled trial (RCT) examined the effectiveness of the play-based ENGAGE intervention in improving behavioral outcomes related to EFs among Finnish preschool-age children with hyperactivity and/or inattention problems. 95 children between 4 and 5 years of age and their parents were randomly assigned to the ENGAGE intervention or a waitlist control group. Parents and early childhood education (ECE) teachers rated the children's EF difficulties and problem behaviors at pre-intervention, post-intervention, and 5-month follow-up. Repeated measures linear mixed modeling was used to examine the effect of ENGAGE on child outcomes. Those receiving ENGAGE exhibited significantly greater decreases in parent-rated attentional problems, hyperactivity/impulsivity, and acting out behaviors than the control group did, with mostly moderate effect sizes. No consistent improvements in the teacher ratings of children's EF related difficulties were found in either group. Low dropout (8%) from the intervention and high acceptability ratings indicated that ENGAGE is a palatable intervention for parents. The present study showed that findings from an earlier RCT on ENGAGE conducted in New Zealand could be generalized to a different cultural setting, as the intervention effectively reduced young Finnish children's EF difficulties in the home context. Extending ENGAGE and other play-based interventions into different everyday contexts of children, such as ECE, could further enhance the beneficial effects on children's EFs and behavior.

Dimensional associations between executive function processes and symptoms of ADHD, ASD, oppositional defiance and anxiety in young school-referred children

Executive function (EF) difficulties are implicated in Neurodevelopmental Disorders (NDDs), such as Autism Spectrum Disorder (ASD) and Attention Deficit Hyperactivity Disorder (ADHD). Because NDDs are highly comorbid and frequently co-occur with additional clinical problems, it is unclear how specific EF problems are associated with symptoms of ASD and ADHD, whilst accounting for co-occurring anxiety or oppositional defiance disorder (ODD) symptoms. The current study utilised a large sample of young children (n = 438, aged 4-8) referred to Cardiff University's Neurodevelopment Assessment Unit (NDAU) by teachers for cognitive and/or socio-emotional problems. As part of the referral process, the teachers completed the Strengths and Difficulties Questionnaire (SDQ), which revealed that most children displayed moderate to high hyperactivity (86%) and prosocial (73%) problems, as well as high levels of symptoms in other clinical domains (41% emotional, 61% conduct and 68% peer problems). Children completed tasks to assess episodic memory, cognitive inhibition, cognitive flexibility and visuomotor control, whilst parents completed questionnaires to measure symptoms of ASD, ADHD, anxiety and ODD. Dimensional analyses showed that poorer cognitive inhibition and visuospatial episodic memory were significantly associated with ADHD symptoms, whereas cognitive flexibility was negatively associated with ODD symptoms. Having more ASD symptoms was associated with fewer cognitive inhibition problems, whereas anxiety was associated with better cognitive flexibility. Our approach to assessment and analysis shows that specific cognitive processes are associated with distinct neurodevelopmental and clinical symptoms, which is ultimately relevant to early identification of and intervention for young children at risk of cognitive and/or socio-emotional problems.

Interventions for Young Children's Mental Health: A Review of Reviews

To determine the efficacy of intervention programs for young children (4-9 years) with emerging mental health needs, we conducted a review of meta-analytic and systematic reviews of the intervention literature. Of 41,061 abstracts identified and 15,076 screened, 152 review articles met the inclusion criteria. We reviewed interventions across multiple disciplines targeting: (1) general mental health concerns; (2) internalizing symptoms; (3) externalizing symptoms; (4) anxiety; (5) depression; (6) trauma; (7) symptoms of attention-deficit/hyperactivity disorder; and (8) mental health concerns associated with autism spectrum disorder. Substantial evidence was found for the efficacy of behavioral and cognitive behavioral interventions for general mental health concerns, externalizing symptoms (generally, as well as ADHD, conduct, and other behavioral symptoms) and internalizing symptoms (generally, as well as anxiety) aged 4-9 years. Emerging evidence was identified for interventions targeting trauma symptoms, depression symptoms, and social, emotional and behavioral symptoms in autism spectrum disorder in children aged 4-9 years. Currently there is only limited emerging evidence regarding non-behavioral or non-cognitive behavioral interventions for programs targeting children ages 4-9 years where the aim is to deliver an evidence-based program to improve child social, emotional and/or behavioral functioning. Given the recent rises in mental health needs reported in children, targeted behavioral-and/or cognitive behavior therapy-based interventions should be made widely available to children (and their families) who experience elevated symptoms.

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.

Early executive control buffers risk for adolescent psychopathology during the COVID-19 pandemic

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has had a global impact on youth mental health, and there is a critical need for research examining individual factors that contribute to increased psychopathology during the pandemic. The current study explored whether executive control (EC) abilities in early childhood interact with COVID-related stress to attenuate risk for adolescent psychopathology during the first 6 months of the pandemic.

METHODS

Participants were 337 youth (49% female) living in a small midwestern city in the United States. Participants completed EC tasks when they were approximately 4.5 years old as part of a longitudinal study investigating cognitive development. At annual laboratory visits during adolescence and before the pandemic, participants (Mage  = 14.57) reported on mental health symptoms. In July and August of 2020, participants (Mage  = 16.57) reported on COVID-related stress and depression, anxiety, and trauma symptoms.

RESULTS

COVID-related stress was associated with increased internalizing problems after controlling for prepandemic symptom levels. Further, the impact of COVID-related stress on adolescent internalizing problems was moderated by preschool EC, with higher levels of EC buffering the effects of COVID-related stress on adolescent internalizing problems.

CONCLUSIONS

Findings highlight the importance of promoting EC early in development, as well as screening for EC deficits and implementing targeted intervention strategies across the lifespan to help reduce the impact of stress on adolescent internalizing problems.

Effect of physical activity on attention in school-age children with ADHD: a systematic review and meta-analysis of randomized controlled trials

Background: Attention problems are one of the core symptoms of Attention-deficit/hyperactivity disorder (ADHD) in children. Previous studies have shown that physical activity intervention has a positive impact on executive function in children and adolescents with ADHD, but there is limited research on attention problems in school-aged children with ADHD. There are still uncertainties about the appropriate physical activity interventions to improve attention problems in this population. This study conducted a Meta-analysis of randomized controlled trials (RCTs) related to physical activity intervention for attention problems in school-aged children with ADHD, providing a certain reference for precise intervention in attention problems for this population. Methods: We systematically searched the following databases up to October 2022: PubMed, Embase, Web of Science, and Cochrane Library, to identify RCTs that investigated the effects of physical activity interventions on children with ADHD. Two investigators independently conducted literature screening, extraction, and quality assessment. We performed a meta-analysis using Stata 15.1. Results: In total, we included 10 studies in this meta-analysis. The results indicated that physical activity intervention had a moderate effect in improving attention problems in school-aged children with ADHD (SMD = -0.48, 95% CI: 0.85, -0.07, p < 0.05). Furthermore, subgroup analysis showed that the effect of physical activity intervention was moderated by intervention type, frequency, and period, rather than the physical activity environment or single intervention time. Conclusion: Our study suggests that cognitively engaging exercise is more effective in improving attention problems in school-aged children with ADHD. Specifically, when cognitive-engaging exercise is used as the type of physical activity and the intervention frequency is less than 3 times per week, with an intervention period of less than weeks, it is most beneficial for improving attention problems in school-aged children with ADHD. However, we should also consider individual differences in children with respect to their ADHD symptoms and accurately evaluate each child's specific symptoms before intervention. Systematic Review Registration: identifier (CRD42022363255).

Heated Behaviour in the Classroom for Children with FASD: The Relationship between Characteristics Associated with ADHD, ODD and ASD, Hot Executive Function and Classroom Based Reward Systems

Possession of characteristics related to Attention Deficit Hyperactive Disorder, Oppositional Defiance Disorder, and Autism Spectrum Disorder in children prenatally exposed to alcohol contributes to challenges within the diagnostic pathway for Foetal Alcohol Spectrum Disorder (FASD). The presentation of these characteristics, though problematic for the children affected, may not result in referral for diagnosis; focusing on diagnostic thresholds masks the dimensional nature of these characteristics. Children with traits which are undiagnosed may not receive effective support and are often identified as exhibiting challenging behaviour. In the UK, children with undiagnosed Special Educational Needs (SEN) are more likely to experience school exclusion. Common across each condition are challenges to executive function associated with emotional regulation (hot-executive function). This study explored the relationship between characteristics of Attention Deficit Hyperactive Disorder, Oppositional Defiance Disorder, Autistic-Like Traits, and hot executive functions on the helpfulness of reward-based interventions for children with suspected or diagnosed FASD. Data were collected online using caregiver referral questionnaire screeners for each measure (Child Autism Quotient Questionnaire, Vanderbilt ADHD Parental Rating Scale and The Childhood Executive Functioning Inventory) for children aged 6–12 years with suspected or diagnosed FASD (n = 121). Between-group comparisons showed no significant difference in the reporting of Attention Deficit Hyperactive Disorder characteristics, Oppositional Defiance Disorder characteristics, Autistic-Like Traits, and executive function, regardless of diagnostic state. Multiple regression analyses indicated that these personality characteristics and executive functions were associated with the perception of the reward system helpfulness. However, this pattern was qualified by both the type of hot executive function challenged (significant for Regulation not Inhibition) and whether the child had an FASD diagnosis. Thus, a dimensional approach may strengthen our understanding of the child’s classroom experience and help overcome barriers to effective intervention and support.

Computerized cognitive training in attention-deficit/hyperactivity disorder (ADHD): a meta-analysis of randomized controlled trials with blinded and objective outcomes

This meta-analysis investigated the effects of computerized cognitive training (CCT) on clinical, neuropsychological and academic outcomes in individuals with attention-deficit/hyperactivity disorder (ADHD). The authors searched PubMed, Ovid, and Web of Science until 19th January 2022 for parallel-arm randomized controlled trials (RCTs) using CCT in individuals with ADHD. Random-effects meta-analyses pooled standardized mean differences (SMD) between CCT and comparator arms. RCT quality was assessed with the Cochrane Risk of Bias 2.0 tool (PROSPERO: CRD42021229279). Thirty-six RCTs were meta-analysed, 17 of which evaluated working memory training (WMT). Analysis of outcomes measured immediately post-treatment and judged to be "probably blinded" (PBLIND; trial n = 14) showed no effect on ADHD total (SMD = 0.12, 95%CI[-0.01 to -0.25]) or hyperactivity/impulsivity symptoms (SMD = 0.12, 95%[-0.03 to-0.28]). These findings remained when analyses were restricted to trials (n: 5-13) with children/adolescents, low medication exposure, semi-active controls, or WMT or multiple process training. There was a small improvement in inattention symptoms (SMD = 0.17, 95%CI[0.02-0.31]), which remained when trials were restricted to semi-active controls (SMD = 0.20, 95%CI[0.04-0.37]), and doubled in size when assessed in the intervention delivery setting (n = 5, SMD = 0.40, 95%CI[0.09-0.71]), suggesting a setting-specific effect. CCT improved WM (verbal: n = 15, SMD = 0.38, 95%CI[0.24-0.53]; visual-spatial: n = 9, SMD = 0.49, 95%CI[0.31-0.67]), but not other neuropsychological (e.g., attention, inhibition) or academic outcomes (e.g., reading, arithmetic; analysed n: 5-15). Longer-term improvement (at ~6-months) in verbal WM, reading comprehension, and ratings of executive functions were observed but relevant trials were limited in number (n: 5-7). There was no evidence that multi-process training was superior to working memory training. In sum, CCT led to shorter-term improvements in WM, with some evidence that verbal WM effects persisted in the longer-term. Clinical effects were limited to small, setting specific, short-term effects on inattention symptoms.

Effectiveness of digital game-based trainings in children with neurodevelopmental disorders: A meta-analysis

Digital game-based training programs have recently been used to train the cognitive abilities of children with neurodevelopmental disorders (NDDs). However, the effects of training remain controversial. The present meta-analysis explored the effectiveness of digital game-based training in children with NDDs and examined the possible moderators of its effects. Twenty-nine studies with cognitive outcomes in 1535 children were included in the present meta-analysis. The results showed that digital game-based training could significantly enhance the core cognitive abilities of children with each type of NDDs and that training could be used remotely. Meanwhile, task content and game features of digital game-based interventions separately make unique and significant contributions to the training effects, suggesting that the combination of training content and game features could efficiently improve children's cognition. Although the present study revealed that the training benefits could be maintained over a period of time, more studies are needed to explore the retention effects of digital game-based training. The present study provides a comprehensive understanding of the training effects of digital game-based interventions and new insights for future cognitive training design and application.

Parent Training for ADHD: No Generalization of Effects From Clinical to Neuropsychological Outcomes in a Randomized Controlled Trial

OBJECTIVE

We examined whether neuropsychological function in ADHD can be improved by the New Forest Parenting Programme (NFPP), that combines standard parenting strategies with self-regulatory skills training, or predict ADHD and quality of life (QoL) treatment effects.

METHOD

Participants were 93 medication-naive preschool children with ADHD (3-7 years) randomized to either NFPP (n = 49) or treatment as usual (TAU; n = 44) in a recent randomized trial. Laboratory measures of executive function, reaction time variability, and delay of gratification were collected along with parent ratings of ADHD and QoL at baseline and post treatment. Ratings were collected again at 3-month follow-up.

RESULTS

NFPP did not improve neuropsychological function (compared to TAU), and baseline neuropsychological function did not predict treatment-related ADHD or QoL effects.

CONCLUSION

Although NFPP includes a neuropsychological training element and has been shown to improve several clinical outcomes, it did not improve the neuropsychological functions it targets.

Digital cognitive training in children with attention-deficit/hyperactivity disorder: a study protocol of a randomised controlled trial

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent neurodevelopmental disorders and is a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with daily functioning. Children with ADHD are developmentally vulnerable, with the disorder linked to emotional regulation difficulties, behavioural disturbances, as well as academic challenges. Emerging evidence suggests that children with ADHD may benefit from cognitive training interventions, including those focused on attention. This study aims to assess the immediate and long-term efficacy of an attention training intervention in children with ADHD.

METHODS AND ANALYSIS

This study is a preregistered, parallel, double blind, randomised controlled trial. Participants will comprise 104 children with a diagnosis of ADHD aged 5-8 years 11 months. Participants will be randomly allocated to either an adaptive, digital game-based (1) attention training programme (intervention) or (2) a numeracy programme (control). Both programmes will be delivered on a touchscreen tablet, and children will complete five 20 min sessions per week for a 5-week period at home (25 sessions in total). Assessments of the primary outcome (ie, attention and inhibitory control) and secondary outcomes (ie, selective attention, interference control, sustained attention, inhibition, behavioural attention, impairment in everyday functioning, working memory and executive functioning) will occur at preintervention, immediately postintervention and at 3-month follow-up. Multivariate linear regression will be employed to examine primary and secondary outcomes. The data analyst will be blinded to group membership.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Monash University HREC (20495). Results will be disseminated through peer-reviewed journals, conference presentations, media outlets, the internet and various community/stakeholder activities.

TRIAL REGISTRATION NUMBER

ACTRN12620000964910, UTN U1111-1250-2620.

Task-Rate-Related Neural Dynamics Using Wireless EEG to Assist Diagnosis and Intervention Planning for Preschoolers with ADHD Exhibiting Heterogeneous Cognitive Proficiency

This study used a wireless EEG system to investigate neural dynamics in preschoolers with ADHD who exhibited varying cognitive proficiency pertaining to working memory and processing speed abilities. Preschoolers with ADHD exhibiting high cognitive proficiency (ADHD-H, n = 24), those with ADHD exhibiting low cognitive proficiency (ADHD-L, n = 18), and preschoolers with typical development (TD, n = 31) underwent the Conners’ Kiddie Continuous Performance Test and wireless EEG recording under different conditions (rest, slow-rate, and fast-rate task). In the slow-rate task condition, compared with the TD group, the ADHD-H group manifested higher delta and lower beta power in the central region, while the ADHD-L group manifested higher parietal delta power. In the fast-rate task condition, in the parietal region, ADHD-L manifested higher delta power than those in the other two groups (ADHD-H and TD); additionally, ADHD-L manifested higher theta as well as lower alpha and beta power than those with ADHD-H. Unlike those in the TD group, the delta power of both ADHD groups was enhanced in shifting from rest to task conditions. These findings suggest that task-rate-related neural dynamics contain specific neural biomarkers to assist clinical planning for ADHD in preschoolers with heterogeneous cognitive proficiency. The novel wireless EEG system used was convenient and highly suitable for clinical application.

Training Willpower: Reducing Costs and Valuing Effort

The integrative model of effortful control presented in a previous article aimed to specify the neurophysiological bases of mental effort. This model assumes that effort reflects three different inter-related aspects of the same adaptive function. First, a mechanism anchored in the salience network that makes decisions about the effort that should be engaged in the current task in view of costs and benefits associated with the achievement of the task goal. Second, a top-down control signal generated by the mechanism of effort that modulates neuronal activity in brain regions involved in the current task to filter pertinent information. Third, a feeling that emerges in awareness during effortful tasks and reflects the costs associated with goal-directed behavior. The aim of the present article is to complete this model by proposing that the capacity to exert effortful control can be improved through training programs. Two main questions relative to this possible strengthening of willpower are addressed in this paper. The first question concerns the existence of empirical evidence that supports gains in effortful control capacity through training. We conducted a review of 63 meta-analyses that shows training programs are effective in improving performance in effortful tasks tapping executive functions and/or self-control with a small to large effect size. Moreover, physical and mindfulness exercises could be two promising training methods that would deserve to be included in training programs aiming to strengthen willpower. The second question concerns the neural mechanisms that could explain these gains in effortful control capacity. Two plausible brain mechanisms are proposed: (1) a decrease in effort costs combined with a greater efficiency of brain regions involved in the task and (2) an increase in the value of effort through operant conditioning in the context of high effort and high reward. The first mechanism supports the hypothesis of a strengthening of the capacity to exert effortful control whereas the second mechanism supports the hypothesis of an increase in the motivation to exert this control. In the last part of the article, we made several recommendations to improve the effectiveness of interventional studies aiming to train this adaptive function."Keep the faculty of effort alive in you by a little gratuitous exercise every day."James (1918, p. 127).

Does central executive training and/or inhibitory control training improve emotion regulation for children with attention-deficit/hyperactivity disorder? A randomized controlled trial

INTRODUCTION

Approximately 48-54% of children with attention-deficit/hyperactivity disorder (ADHD) have impairing difficulties with emotion regulation, and these difficulties are not ameliorated by first-line ADHD treatments. Working memory and inhibitory control represent promising intervention targets given their functional, if not causal, links with ADHD-related emotion dysregulation.

METHODS

This preregistered randomized controlled trial tested whether two digital therapeutic training protocols that have been previously shown to improve working memory (Central Executive Training [CET]) and inhibitory control (Inhibitory Control Training [ICT]) can improve emotion regulation in a sample of 94 children with ADHD aged 8-13 years (M = 10.22, SD = 1.43; 76% White/non-Hispanic; 29 girls).

RESULTS

Results of Bayesian mixed model ANOVAs indicated both treatment groups demonstrated significant decreases in emotion dysregulation relative to pre-treatment at immediate post-treatment (parent report; d = 1.25, BF₁₀ = 8.04 × 10¹³, p < 0.001), at 1-2 months after completing treatment (teacher report; d = 0.99, BF₁₀ = 1.22 × 10⁶, p < 0.001), and at 2-4-months follow-up (parent report; d = 1.22, BF₁₀ = 1.15 × 10¹⁴, p < 0.001). Contrary to our hypotheses, the CET and ICT groups demonstrated equivalent reductions in emotion dysregulation and maintenance of effects. Exploratory analyses revealed that results were robust to control for informant expectancies, ADHD medication status/changes, in-person vs. at-home treatment, child age, and time from treatment completion to post-treatment ratings.

DISCUSSION

To determine whether working memory and inhibitory control are causally linked with ADHD-related emotion dysregulation, future studies should include active control conditions that do not train executive functions prior to making decisions about the clinical utility of CET/ICT for the treatment of emotion dysregulation in ADHD.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov/], identifier [NCT03324464].

Working memory and reaction time variability mediate the relationship between polygenic risk and ADHD traits in a general population sample

Endophenotypes are heritable and quantifiable traits indexing genetic liability for a disorder. Here, we examined three potential endophenotypes, working memory function, response inhibition, and reaction time variability, for attention-deficit hyperactivity disorder (ADHD) measured as a dimensional latent trait in a large general population sample derived from the Adolescent Brain Cognitive Development^SM Study. The genetic risk for ADHD was estimated using polygenic risk scores (PRS) whereas ADHD traits were quantified as a dimensional continuum using Bartlett factor score estimates, derived from Attention Problems items from the Child Behaviour Checklist and Effortful Control items from the Early Adolescent Temperament Questionnaire-Revised. The three candidate cognitive endophenotypes were quantified using task-based performance measures. Higher ADHD PRSs were associated with higher ADHD traits, as well as poorer working memory performance and increased reaction time variability. Lower working memory performance, poorer response inhibition, and increased reaction time variability were associated with more pronounced ADHD traits. Working memory and reaction time variability partially statistically mediated the relationship between ADHD PRS and ADHD traits, explaining 14% and 16% of the association, respectively. The mediation effect was specific to the genetic risk for ADHD and did not generalise to genetic risk for four other major psychiatric disorders. Together, these findings provide robust evidence from a large general population sample that working memory and reaction time variability can be considered endophenotypes for ADHD that mediate the relationship between ADHD PRS and ADHD traits.

The World Federation of ADHD International Consensus Statement: 208 Evidence-based conclusions about the disorder

BACKGROUND

Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with strong evidence base.

METHODS

We reviewed studies with more than 2000 participants or meta-analyses from five or more studies or 2000 or more participants. We excluded meta-analyses that did not assess publication bias, except for meta-analyses of prevalence. For network meta-analyses we required comparison adjusted funnel plots. We excluded treatment studies with waiting-list or treatment as usual controls. From this literature, we extracted evidence-based assertions about the disorder.

RESULTS

We generated 208 empirically supported statements about ADHD. The status of the included statements as empirically supported is approved by 80 authors from 27 countries and 6 continents. The contents of the manuscript are endorsed by 366 people who have read this document and agree with its contents.

CONCLUSIONS

Many findings in ADHD are supported by meta-analysis. These allow for firm statements about the nature, course, outcome causes, and treatments for disorders that are useful for reducing misconceptions and stigma.

Promoting EF With Preschool Interventions: Lessons Learned From 15 Years of Conducting Large-Scale Studies

In the past two decades, a growing number of early childhood interventions that aim to improve school readiness have also targeted children's executive function (EF), building on the theory that promoting EF skills in preschool may play a key role in reducing the substantial gaps in school readiness and later achievement associated with family income. Despite the expansion of school readiness interventions across preschool, research evidence is mixed regarding what works to promote EF development and the impact of these interventions on children's EF skills, and subsequently, their academic and behavioral outcomes. This paper reviews four intervention approaches designed to support school readiness that may also improve children's EF skills by: (a) encouraging adaptive classroom behaviors, (b) improving social-emotional learning, (c) promoting play and direct training of EF skills, and (d) improving cognitive skills related to EF. We describe program effects from rigorous trials testing these approaches, including summarizing the takeaways from four large-scale intervention research studies conducted by the authors, involving over 5,000 children. We conclude by exploring open questions for the field and future directions for research and intervention program development and refinement.