Psychological heterogeneity in AD/HD--a dual pathway model of behaviour and cognition

Functional connectivity anomalies in medication-naive children with ADHD: Diagnostic potential, symptoms interpretation, and a mediation model

OBJECTIVE

To identify reliable electroencephalography (EEG) biomarkers for attention deficit/hyperactivity disorder (ADHD) by investigating anomalous functional connectivity patterns and their clinical relevance.

METHODS

Resting-state EEG data were collected from 74 children aged 6-12 (33 unmedicated ADHD; 41 typically developing). Functional connectivity was quantified using the imaginary part of coherency (ICOH). Machine learning (ML)-based support vector machine (SVM) modeling, regression, and mediation analyses linked connectivity features to symptom severity and diagnostic classification.

RESULTS

Children with ADHD exhibited beta (β) band hypo-connectivity in frontal regions (Fp2-F4, Fp1-Cz, F7-Cz) and theta (θ) band hyper-connectivity in left parietal-central networks (C3-P7, P3-P7, etc.). An SVM classifier achieved an average area under the curve of 0.89 using three connectivity features. Left parietal θ band hyper-connectivity (C3-P7) correlated with both inattention and hyperactivity/impulsivity and mediated their interrelationship.

CONCLUSIONS

ADHD is characterized by disrupted frontoparietal connectivity, with θ band hyper-connectivity in sensory-integration networks potentially compensating for impaired frontal regulation.

SIGNIFICANCE

These findings highlight C3-P7 θ band connectivity as both a diagnostic and mechanistic biomarker, providing novel target for neurofeedback therapies and enhancing the differential diagnosis in neurodevelopmental disorders.

Boredom proneness and inattention in children with and without ADHD: the mediating role of delay aversion

Objective

A high tendency to boredom and delay aversion are commonly observed traits among children and adolescents diagnosed with ADHD. However, the interplay between boredom, delay aversion, and ADHD symptoms remains unclear. It is unknown, for example, whether a predisposition to boredom predicts difficulties in sustaining attention because of susceptibility to delay aversion. This study investigated the potential mediating role of delay aversion in the relationship between boredom and inattentive behaviors in children with and without ADHD.

Methods

Parent- and self-ratings of boredom proneness, delay aversion, and inattention symptom severity of 93 children with ADHD and 90 typically developing controls (aged 9-16 years) were included in analysis.

Results

Both parent- and self-ratings showed that children with ADHD had significantly elevated levels of trait boredom, delay aversion, and inattention compared to controls. Trait boredom, delay aversion, and inattention were inter-correlated. The parent-ratings showed that children with a higher level of trait boredom tended to be more inattentive, and this effect was partially explained by the mediating role of delay aversion.

Conclusions

Our findings suggest that the relation between boredom and inattention may be at least partially explained by the mediating role of delay aversion in children within and without ADHD.

Behavioral and neurofunctional profiles of delay aversion in children with attention-deficit hyperactivity disorder

Despite substantial efforts to unravel cognitive heterogeneity in ADHD, the examination of motivational variability, particularly delay aversion, remains limited. This study aimed to identify homogeneous delay-averse profiles in children with ADHD to understand motivational deficits. Delay-averse profiles were examined in a clinically well-characterized sample of 43 children with ADHD and 47 control participants using cluster analyses on an experiential delay discounting task. External validation analyses included parents' and teachers' clinical ratings, and fNIRS-based resting-state functional connectivity (rsFC) from the frontoparietal (FPN) and the default mode (DMN) networks. A five-profile solution best fit the data. Two clusters, labeled Conventional and Conventional-steeper, exhibited a conventional reward discount with increased delay but differed in the discounting slope. Three clusters demonstrated altered discounting: Steep discounting (abrupt devaluation of the reward), Shallow discounting (shallow discounting), and Zero discounting (no devaluation across delay durations). 77.78% of ADHD-C children clustered into steep discounting profiles, while 41.67% of ADHD-IN children were found in Shallow and Zero profiles, showing a significant disparity in the distribution of categorical presentations. External validation showed no differences in clinical ratings. However, clusters showing Zero and Shallow discounting demonstrated hypoconnectivity within and between FPN and DMN nodes. Delay aversion in ADHD spans a continuum from decreased to increased discounting rather than being solely defined by steeper discounting. These findings highlight the relevance of dimensional approaches in capturing ADHD's motivational heterogeneity and identifying distinct neurobiological substrates, with implications for improving diagnostic protocols and intervention strategies through the incorporation of behavioral measures of reward processing.

The Multidimensional Dynamic Feedback Model: A Comprehensive Framework for Understanding and Managing Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by persistent inattention, hyperactivity, and impulsivity. These symptoms can significantly impact academic performance, social interactions, and daily activities, often creating cycles that worsen long-term challenges. This review introduces the Multidimensional Dynamic Feedback Model (MDFM), which aids in understanding ADHD's development and guiding intervention strategies. The model emphasizes the dynamic interactions among genetic, environmental, cognitive, and behavioral factors. The MDFM consists of three key aspects: (1) the interplay between genetic and environmental factors in shaping ADHD's biological basis, (2) the role of cognitive and neural processes in driving core symptoms, and (3) the influence of behavioral feedback loops that reinforce negative behaviors and hinder adaptation. The model highlights the importance of personalized interventions and effective feedback systems, including early prevention, supportive family and school environments, and the impact of social and cultural backgrounds on treatment outcomes. As a comprehensive framework, the MDFM offers a holistic perspective for clinicians, aiming to enhance long-term outcomes and promote the health and well-being of individuals with ADHD across the lifespan. By addressing implementation challenges, the model seeks to improve ADHD prevention and management, ultimately supporting individuals and their communities.

The Upside of ADHD-related Risk-taking: Adolescents With ADHD Report a Higher Likelihood of Engaging in Prosocial Risk-taking Behavior Than Typically Developing Adolescents

BACKGROUND

ADHD is highly prevalent in adolescents. ADHD is characterized by heightened impulsive behavior and is often associated with increased risk-taking behavior in adolescence. Previous research has mostly focused on negative aspects of risk-taking behavior. However, recently two other types of risk-taking behavior have been identified: positive and prosocial risk-taking.

OBJECTIVE

Here, we tested whether youth with ADHD are more inclined toward positive and prosocial risk-taking.

METHODS

We assessed the self-reported likelihood of engaging in negative, positive, and prosocial risk-taking in a sample of 50 adolescents with ADHD (Mage = 16.3, SD = 1.18) and 54 typically developing adolescents (Mage = 16.9, SD = 0.73). Regardless of group, we found that positive, prosocial, and negative risk-taking behavior were positively correlated, higher risk-taking in one domain was associated with higher levels of risk-taking in another.

RESULTS

Crucially, we found that adolescents with ADHD were more likely to engage in prosocial risk-taking behavior compared to typically developing adolescents. We did not find group differences for negative and positive risk-taking behavior.

CONCLUSION

Together, these results show a first indication of the upside of risk-taking in ADHD.

Methylphenidate stabilizes dynamic brain network organization during tasks probing attention and reward processing in stimulant-naïve children with ADHD

Children with ADHD often exhibit fluctuations in attention and heightened reward sensitivity. Psychostimulants, such as methylphenidate (MPH), improve these behaviors in many, but not all, children with ADHD. Given the extent to which psychostimulants are prescribed for children, coupled with variable efficacy on an individual level, a better understanding of the mechanisms through which MPH changes brain function and behavior is necessary. MPH's primary action is on catecholamines, including dopamine and norepinephrine. Catecholaminergic signaling can influence the tradeoff between flexibility and stability of brain function, which is one candidate mechanism through which MPH may alter brain function and behavior. Time-varying functional connectivity, which models how functional brain networks reconfigure on short timescales, can be used to examine brain flexibility versus stability, and is thus well-suited to test how MPH impacts brain function. Here, we scanned stimulant-naïve children with ADHD (8-12 years) on and off a single dose of MPH. In the MRI machine, participants completed two attention-demanding tasks: 1) a standard go/no-go task and 2) a rewarded go/no-go task. For both tasks, using a within-subjects design, we compared the degree to which brain organization changed throughout the course of the MRI scan, termed whole brain flexibility, on and off MPH. We found that whole brain flexibility decreased on MPH. Further, individuals with greater decreases in whole brain flexibility on MPH exhibited greater improvements in task performance. Together, these results provide novel insights into the neurobiological mechanisms underlying the effectiveness of MPH administration for children with ADHD.

Attention Deficit Hyperactivity Disorder, Cannabis Use, and the Endocannabinoid System: A Scoping Review

There is emerging evidence that the endocannabinoid system (ECS) plays a significant role in the pathophysiology of many psychiatric disorders, including attention deficit hyperactivity disorder (ADHD). Increasing evidence suggests that a number of neurobiological correlates between endogenous cannabinoid function and cognitive dysfunction are seen in ADHD, making the ECS a possible target for therapeutic interventions. Cannabis use and cannabis use disorder are more prevalent in individuals with ADHD, compared to the general population, and there is growing popular perception that cannabis is therapeutic for ADHD. However, the relationship between cannabis use and ADHD symptomology is poorly understood. Further understanding of the role of the ECS in ADHD pathophysiology and the molecular alterations that may be a target for treatment is needed. To further the science on this emerging area of research, this scoping review describes the preclinical and clinical evidence seeking to understand the relationship between the ECS and ADHD.

The apple does not fall far: stable predictive relationships between parents' ratings of their own and their children's self-regulatory abilities

Having control over your own behavior and impulses is a critical skill that influences children's academic, social, and emotional development. This study investigates the stability and predictive relationships between parents' ratings of their own and their children's executive function and delay aversion. Using data from approximately 1700 families collected during the COVID-19 pandemic, we employed hierarchical structural equation models and cross-lagged panel models to analyze the temporal stability and directional influences of executive function and delay aversion assessments.Our analysis revealed a substantial latent correlation (r = 0.48, p < 0.001) between parents' and children's executive function problems, indicating a shared variance of approximately 23%. Significant cross-lagged effects were found, with parental executive functions at T1 predicting child executive functions at T2 (β = 0.16, p = 0.005). For delay aversion, we found a latent correlation of r = 0.53 (p < 0.001) and significant within-timepoint and temporal stability, but no cross-lagged effects.These findings suggest that higher levels of executive function problems reported by parents at T1 correspond to an increased perception of similar problems in their children at T2. This highlights the importance of parental self-perception in assessing children's abilities. Our results highlight the importance of incorporating family dynamics into interventions targeting executive function difficulties and delay aversion in children, and understanding this interplay enables the development of more effective, individualized approaches to support positive developmental outcomes.

Social functioning in children with ADHD: an examination of inhibition, self-control, and working memory as potential mediators

Children with attention-deficit/hyperactivity disorder (ADHD) experience a host of social problems, in addition to significant impairments in behavioral inhibition, working memory, and self-control. Behavioral inhibition and working memory difficulties have been linked with social functioning deficits, but to date, most studies have examined these neurocognitive problems either in isolation or as an aggregate measure in relation to social problems, and none has considered the role of self-control. Thus, it remains unclear whether all of these executive functions are linked with social problems or if the link can be more parsimoniously explained by construct overlap. Fifty-eight children with ADHD and 63 typically developing (TD) children completed tests assessing self-control, behavioral inhibition, and working memory; parents and teachers rated children's social functioning. Examination of potential indirect effects with the bootstrapping procedure indicated that working memory mediated the relation between group membership (ADHD, TD) and child social functioning based on teacher but not parent ratings. Behavioral inhibition and self-control did not have direct relations with either parent- or teacher-rated social functioning. These findings point to important differences regarding how executive functioning difficulties manifest at school compared to home, as well as the specific executive function components that predict ADHD-related social difficulties.

Absent or Hidden? Hyperactivity in Females With ADHD

OBJECTIVE

This study aimed to objectively assess signs of hyperactivity in adults suspected of having ADHD, addressing potential sex bias in diagnosis.

METHODS

About 13,179 (49% female) adults with an average age of 33 years with ADHD and 1,910 (41% female) adults with an average age of 36 years without ADHD were included. Motor activity was measured using the Quantified Behavioral Test, analyzing "provoked," and "basal" activity. Sex by group differences were analyzed using analysis of variance.

RESULTS

Results showed significant ADHD effects on the basal and provoked activity measures, while sex effects were only notable for provoked activity. Males, irrespective of diagnosis, exhibited higher provoked activity than females, while both sexes with ADHD displayed approximately twice the basal activity and about three times the provoked activity compared to their respective sex controls.

CONCLUSION

These findings suggest that females with ADHD suffer equally from hyperactivity compared to males, challenging the notion of a sex-dependent presentation of hyperactivity. This may lead to more accurate and timely diagnoses, reducing ADHD-related burdens and comorbidities in females.

Acute aerobic exercise modulates cognition and cortical excitability in adults with attention-deficit hyperactivity disorder (ADHD) and healthy controls

Evidence suggests aerobic exercise has beneficial effects on cognitive performance in adults with attention-deficit hyperactivity disorder (ADHD). The underlying mechanisms might depend on mechanisms of exercise-mediated brain physiology. The study aims to investigate the effects of acute aerobic exercise on cortical excitability and cognitive performance, and the correlation between these phenomena in adults with ADHD. Twenty-six drug-naïve ADHD adults, and twenty-six age-, and gender-matched healthy controls were assessed with respect to cortical excitability and cognitive performance before and after acute aerobic exercise (a single session for 30 min) or a control intervention. The results show significantly enhanced intracortical facilitation (ICF) and decreased short intracortical inhibition (SICI) after aerobic exercise in healthy subjects. In contrast, SICI was significantly enhanced following acute aerobic exercise in ADHD. In ADHD, furthermore inhibitory control and motor learning were significantly improved after the acute aerobic exercise intervention. Alterations of SICI induced by aerobic exercise, and inhibitory control and motor learning improvement were significantly positively correlated in the ADHD group. Aerobic exercise had partially antagonistic effects in healthy controls, and ADHD patients. Furthermore, aerobic exercise-induced cognition-enhancing effects in ADHD depend on specific alterations of brain physiology, which differ from healthy humans.

Maternal psychopathology is differentially associated with adolescent offspring neural response to reward given offspring ADHD risk

Reinforcement sensitivity is a hypothesized attention-deficit/hyperactivity disorder (ADHD) intermediate phenotype but its role in transgenerational transmission of ADHD-linked psychopathology risk is largely unknown. We examined, in a carefully phenotyped, N = 123 sample of adolescents (Mage = 15.27 years, SD = 0.984; 61.78% boys), whether (1) parental psychopathology is differentially associated with fMRI-indexed neural response to reward receipt and (2) both maternal and paternal psychopathology are associated with neural response to reward; across adolescents at-risk for and not at-risk for ADHD. Indices of parental psychopathology were differentially associated with adolescent offspring neural response to reward such that across measures, parental psychopathology was negatively or not associated with offspring superior frontal gyrus (SFG) response to reward receipt in adolescents at-risk for ADHD, but parental psychopathology was positively associated with offspring SFG response in adolescents not at-risk. Further, across measures, greater maternal psychopathology was associated with blunted adolescent SFG response to reward in adolescents at-risk for ADHD whereas greater maternal externalizing problems were linked to enhanced adolescent SFG response in adolescents not at-risk. Across measures, paternal psychopathology was not associated with adolescent response to reward, in either group. ADHD risk confers differential reward-related susceptibility to the effects of parental psychopathology. Results also show this association is nonspecific in terms of parental psychopathology type but is specific to maternal psychopathology.

Delay of Gratification in Preschoolers with Autism and Concerns for ADHD

OBJECTIVE

Self-regulation abilities in childhood are predictive of a range of challenges later in life, making it important to identify difficulties in this area as early as possible. Autistic children and those with attention-deficit/hyperactivity disorder (ADHD) often have difficulties with self-regulation, but little is known about the similarities and differences in such abilities across neurodevelopmental conditions.

METHOD

We examined self-regulation using a delay of gratification task in 36-month-old autistic children (n = 20), those showing clinically relevant concerns for ADHD (i.e. ADHD Concerns; n = 24), and Comparison children without these conditions (n = 130); early predictors of self-regulation were also assessed.

RESULTS

Both the Autism and ADHD Concerns groups had greater difficulty waiting for a desired snack than the Comparison group. At the longest delay trial (30 seconds), a substantial percentage of autistic children (50%) and those with ADHD Concerns (35%) consumed the snack prematurely, in contrast to only 16% of the Comparison group. Parent-reported temperament-based impulsivity at 18 months and examiner-observed ADHD-like traits at 24 months were associated with increased self-regulation challenges at 36 months, regardless of group. Adjusting for verbal abilities attenuated some of these differences and associations, suggesting that language may be an important mechanism undergirding early self-regulatory abilities.

CONCLUSION

Given possible links between preschool self-regulation and a range of critical functional outcomes, future studies may explore the efficacy of early interventions targeting impulsivity and regulatory behaviors in infants and toddlers at elevated likelihood for developing self-regulation challenges to potentially reduce the impact of these difficulties later in life.

The Impact of Sex on Cognitive Control in ADHD: Girls Slow to Inhibit, Boys Inhibit Less, and Both Show Higher Response Variability

OBJECTIVE

To determine whether girls and boys with ADHD show distinct impairments in components of cognitive control across multiple tasks (go/no-go, stop signal, and flanker) and performance metrics (response speed, variability, and errors).

METHOD

A total of 300 children, ages 8 to 12 years with ADHD (n = 210, 58 girls) or typically developing (TD; n = 99, 37 girls), completed all tasks. Traditional response measures (e.g., mean and standard deviation of reaction time, inhibition errors, and stop signal reaction time) and ex-Gaussian modeling of reaction times (mu, sigma, and tau) were analyzed.

RESULTS

Girls showed intact response inhibition in the context of slower response speed, while boys made more inhibition errors and did not slow their response speed. Both girls and boys with ADHD showed higher response variability and poorer interference control than TD children.

CONCLUSION

Girls and boys with ADHD show distinct impairments in cognitive control that may be important for understanding the pathophysiology of ADHD.

The common factor of executive functions measures nothing but speed of information uptake

There is an ongoing debate about the unity and diversity of executive functions and their relationship with other cognitive abilities such as processing speed, working memory capacity, and intelligence. Specifically, the initially proposed unity and diversity of executive functions is challenged by discussions about (1) the factorial structure of executive functions and (2) unfavorable psychometric properties of measures of executive functions. The present study addressed two methodological limitations of previous work that may explain conflicting results: The inconsistent use of (a) accuracy-based vs. reaction time-based indicators and (b) average performance vs. difference scores. In a sample of 148 participants who completed a battery of executive function tasks, we tried to replicate the three-factor model of the three commonly distinguished executive functions shifting, updating, and inhibition by adopting data-analytical choices of previous work. After addressing the identified methodological limitations using drift-diffusion modeling, we only found one common factor of executive functions that was fully accounted for by individual differences in the speed of information uptake. No variance specific to executive functions remained. Our results suggest that individual differences common to all executive function tasks measure nothing more than individual differences in the speed of information uptake. We therefore suggest refraining from using typical executive function tasks to study substantial research questions, as these tasks are not valid for measuring individual differences in executive functions.

Settling a distracted globe: An overview of psychosocial and psychotherapeutic treatment of attention-deficit/hyperactivity disorder

While the currently prevailing theory of ADHD postulates a neurobiological background and core deficits of behavioural inhibition and executive functioning as the basis of ADHD symptoms, our current conceptualisation also acknowledges the essential contributory role of psychosocial, ecological, and cognitive factors. Considering the multifactorial background of ADHD, its treatment equally needs to be multifactorial involving, besides pharmacotherapy, skill development and psychotherapy as well, especially if we postulate the increasing contribution of social factors in the background of the increasing burden of ADHD. Pharmacotherapies, including stimulants and non-stimulant ADHD medications applied as first-line treatments have a positive effect on core behavioural symptoms, however, they often do not sufficiently remediate several other symptoms and comorbid disorders, which are consequences of ADHD, especially considering that ADHD persists into adulthood and is present over the whole life span. Furthermore, pharmacological treatment is not sufficient to substitute for the skills needed to manage symptoms and adapt well to the environment. As part of a multimodal treatment approach, psychological therapies for ADHD target, besides core ADHD symptoms, other associated features including emotional dysregulation, personality development, neurocognitive dysfunction, depression, anxiety, and sleep problems. Insufficiently treated ADHD may contribute to psychological and personality developmental problems in children, as well as increased health costs and decreased productivity warranting multimodal treatment to address the areas not sufficiently targeted by ADHD-specific pharmacotherapy.

A critical review of hot executive functioning in youth attention-deficit/hyperactivity disorder: Methodological limitations, conceptual considerations, and future directions

Hot executive functioning (EF) - EF under emotionally or motivationally salient conditions - is a putative etiology of attention-deficit/hyperactivity disorder (ADHD), disruptive behavior problems (DBPs), and their related impairments. Despite two decades of research, the present study is the first review of the construct in youth ADHD, with a particular focus on the role of task design, age, and DBPs, as well as relevant conceptual and methodological considerations. While certain hot EF tasks have been investigated extensively (e.g., choice impulsivity), substantial inconsistency in measurement of the broader construct remains, severely limiting conclusions. Future research should a) consider the extent to which various hot EF tasks relate to one another, a higher order factor, and other related constructs; b) further investigate task design, particularly the elicitation of emotion or motivation and its anticipated effect on EF; and c) incorporate multiple levels of analysis to validate similarities and differences among tasks with regard to the affective experiences and cognitive demands they elicit. With improved measurement and conceptual clarity, hot EF has potential to advance the literature on etiological pathways to ADHD, DBPs and associated impairments and, more broadly, may represent a useful tool for understanding the influence of emotion and motivation on cognition.

Emotion dysregulation and depressive symptoms mediate the association between inhibitory control difficulties and aggressive behaviour in children with ADHD

Background/objectives

Impulsive aggressive behaviour, although not a core symptom, is often part of the clinical presentation of attention-deficit/hyperactivity disorder (ADHD). Recently, impulsive aggression has been attributed to emotion dysregulation, which is currently conceptualised as a transdiagnostic factor and seems to contribute to the co-occurrence of other problems in ADHD. Thus, this study investigated the presence of impulsive aggressive behaviour and explored whether emotion dysregulation mediates the relationship between inhibitory control difficulties and aggressive behaviour in children with ADHD. Because ADHD may act as a risk factor for the development of other conditions, such as internalising problems, we aimed to understand whether depressive symptoms contribute to this relationship.

Methods

Seventy-two children were recruited from a hospital and the community, 38 of whom had ADHD and 34 were typically developing (TD). Parents completed the Child Behaviour Checklist, the Behaviour Rating Inventory of Executive Function, and the Emotion Regulation Checklist. Simple mediation and serial mediation models were performed to test our hypotheses.

Results

Aggressive behaviour was significantly higher in ADHD children compared to TD children. Emotion dysregulation fully mediated the relationship between inhibitory control difficulties and aggressive behaviour in ADHD children. Adding depressive symptoms to the model increased the explained variance in aggressive behaviour.

Conclusion

The main result of our study supports the role of emotion dysregulation and depressive symptoms in mediating the relationship between inhibitory control difficulties and impulsive aggressive behaviour in children with ADHD. This highlights that aggressive behaviour is, in part, a result of the inability of the child to appropriately regulate their emotions. Future interventions may be tailored to improve emotion regulation skills to address aggressive behaviour.

Psychometric properties of the Chinese version of the Quick Delay Questionnaire (C-QDQ) and ecological characteristics of reward-delay impulsivity of adults with ADHD

BACKGROUND

The Quick Delay Questionnaire (QDQ) is a short questionnaire designed to assess delay-related difficulties in adults. This study aimed to examine the reliability and validity of the Chinese version of the QDQ (C-QDQ) in Chinese adults, and explore the ecological characteristics of delay-related impulsivity in Chinese adults with attention-deficit/hyperactivity disorder (ADHD).

METHODS

Data was collected from 302 adults, including ADHD (n = 209) and healthy controls (HCs) (n = 93). All participants completed the C-QDQ. The convergent validity, internal consistency, retest reliability and confirmatory factor analysis (CFA) of the C-QDQ were analyzed. The correlations between C-QDQ and two laboratory measures of delay-related difficulties and Barratt Impulsiveness Scale-11 (BIS-11), the comparison of C-QDQ scores between ADHD subgroups and HCs were also analyzed.

RESULTS

The Cronbach's α of C-QDQ was between 0.83 and 0.89. The intraclass correlation coefficient of C-QDQ was between 0.80 and 0.83. The results of CFA of C-QDQ favoured the original two-factor model (delay aversion and delay discounting). Significant positive associations were found between C-QDQ scores and BIS-11 total score and performance on the laboratory measure of delay-related difficulties. Participants with ADHD had higher C-QDQ scores than HCs, and female ADHD reported higher scores on delay discounting subscale than male. ADHD-combined type (ADHD-C) reported higher scores on delay aversion subscale than ADHD-inattention type (ADHD-I).

CONCLUSION

The C-QDQ is a valid and reliable tool to measure delay-related responses that appears to have clinical utility. It can present the delay-related impulsivity of patients with ADHD. Compared to HCs, the level of reward-delay impulsivity was higher in ADHD.

Community-Delivered Evidence-Based Practice and Usual Care for Adolescent Attention-Deficit/Hyperactivity Disorder: Examining Mechanistic Outcomes

Previous research suggests that routine psychosocial care for adolescents with attention-deficit/hyperactivity disorder (ADHD) is an eclectic and individualized mix of diluted evidence-based practices (EBPs) and low-value approaches. This study evaluated the extent to which a community-delivered EBP and usual care (UC) for adolescents with ADHD produce differential changes in theorized behavioral, psychological, and cognitive mechanisms of ADHD. A randomized community-based trial was conducted with double randomization of adolescent and community therapists to EBP delivery supports (Supporting Teens' Autonomy Daily [STAND]) versus UC delivery. Participants were 278 culturally diverse adolescents (ages 11-17) with ADHD and caregivers. Mechanistic outcomes were measured at baseline, post-treatment, and follow-up using parent-rated, observational, and task-based measures. Results using linear mixed models indicated that UC demonstrated superior effects on parent-rated and task-based executive functioning relative to STAND. However, STAND demonstrated superior effects on adolescent motivation and reducing parental intrusiveness relative to UC when it was delivered by licensed therapists. Mechanisms of community-delivered STAND and UC appear to differ. UC potency may occur through improved executive functioning, whereas STAND potency may occur through improved teen motivation and reducing low-value parenting practices. However, when delivered by unlicensed, community-based therapists, STAND did not enact proposed mechanisms. Future adaptations of community-delivered EBPs for ADHD should increase supports for unlicensed therapists, who comprise the majority of the community mental health workforce.

Fifty years of executive control research in attention-deficit/hyperactivity disorder:What we have learned and still need to know

For 50 years, attention-deficit/hyperactivity disorder (ADHD) has been considered a disorder of executive control (EC), the higher-order, cognitive skills that support self-regulation, goal attainment and what we generally call "attention." This review surveys our current understanding of the nature of EC as it pertains to ADHD and considers the evidence in support of eight hypotheses that can be derived from the EC theory of ADHD. This paper provides a resource for practitioners to aid in clinical decision-making. To support theory building, I draw a parallel between the EC theory of ADHD and the common gene-common variant model of complex traits such as ADHD. The conclusion offers strategies for advancing collaborative research.

The emerging evidence on the association between symptoms of ADHD and gaming disorder: A systematic review and meta-analysis

The co-existence of gaming disorder (GD) with other mental health problems has been widely reported. Despite the growing research interest in the comorbidity of GD with attention-deficit/hyperactivity disorder (ADHD), to date, no quantitative synthesis has been performed. The present study comprised a systematic literature search using Scopus, Science Direct, Web of Science, and PubMed databases. Three types of studies were included in the analyses: studies reporting (i) correlation coefficients between the symptoms of GD and ADHD, (ii) means, and standard deviations for comparison of GD severity between ADHD/non-ADHD individuals, and (iii) comparison of ADHD severity between GD/non-GD individuals. The results indicated a moderate relationship between GD and ADHD symptom severity when both subdomains of ADHD were combined (r = 0.296), and also when only inattention (r = 0.306) or hyperactivity (r = 0.266) symptoms were analyzed, which was also confirmed in a structural equation model meta-analysis. Studies showed a large average difference comparing the GD symptom severity of ADHD and non-ADHD individuals (g = 0.693), or ADHD symptom severity of GD and non-GD individuals (g = 0.854). In some cases, higher estimates of association were reported among studies that (i) had a higher proportion of males, (ii) assessed problematic internet use among predominantly videogame player samples rather than assessing only GD, and (iii) had been more recently published. The present review shows that this is an emerging field demonstrating significant results in cross-sectional correlational studies. However, future research should apply more rigorous methodologies to investigate the relationship further (e.g., longitudinal studies and studies using professional/clinical ratings and diagnosis). These results suggest that screening and treatment for ADHD among individuals with gaming disorder is necessary, and individuals with ADHD should be made aware of their higher susceptibility to gaming disorder.

An Individualized, Data-Driven Biological Approach to Attention-Deficit/Hyperactivity Disorder (ADHD) Heterogeneity

Attention-deficit/hyperactivity disorder (ADHD) is the most commonly diagnosed mental health disorder in childhood, however, there is well-established heterogeneity in both the presentation of ADHD symptoms and secondary characteristics across the literature. Existing Diagnostic and Statistical Manual of Mental Disorders (DSM-5) nosology has been ineffective in explaining such heterogeneity in terms of both pathophysiology and clinical trajectories. The current study investigated ADHD heterogeneity via a biologically-based, data-driven approach (k-Means algorithm). Specifically, unique biological profiles (derived from patterns of parasympathetic and sympathetic functioning) were identified and utilized as predictors of clinical presentations. Two hundred eighty-nine participants (167 youth with ADHD), ages 5 to 13 years, completed an emotion-based task while indexes of parasympathetic (i.e., respiratory sinus arrhythmia [RSA]) and sympathetic (i.e., electrodermal activity [EDA]) activity were obtained. Overall, results suggest that three distinct biological profiles among youth with ADHD are evident, with biological profiles differing in regulation and arousal levels during emotionally evocative contexts: (Profile 1) underregulated, hyperaroused (negative contexts only), (Profile 2) typically regulated, underaroused, and (Profile 3) overregulated (positive contexts only), hyperaroused. Results are supported by several dopaminergic- and reward-based theories, integrating differing concepts across the literature, and adds biological support for existing models. Behaviorally, results may translate into differing clinical presentations, however, further work is needed. In general, youth with ADHD are heterogenous in autonomic functioning, which could have implications for synthesizing across differing theories within the literature, predicting clinical presentations, and developing targeted treatments.

Methylphenidate as a treatment option for substance use disorder: a transdiagnostic perspective

A transition in viewing mental disorders from conditions defined as a set of unique characteristics to one of the quantitative variations on a collection of dimensions allows overlap between disorders. The overlap can be utilized to extend to treatment approaches. Here, we consider the overlap between attention-deficit/hyperactivity disorder and substance use disorder to probe the suitability to use methylphenidate as a treatment for substance use disorder. Both disorders are characterized by maladaptive goal-directed behavior, impaired cognitive control, hyperactive phasic dopaminergic neurotransmission in the striatum, prefrontal hypoactivation, and reduced frontal cortex gray matter volume/density. In addition, methylphenidate has been shown to improve cognitive control and normalize associated brain activation in substance use disorder patients and clinical trials have found methylphenidate to improve clinical outcomes. Despite the theoretical basis and promising, but preliminary, outcomes, many questions remain unanswered. Most prominent is whether all patients who are addicted to different substances may equally profit from methylphenidate treatment.

The domain-variant indirect association between electrophysiological response to reward and ADHD presentations is moderated by dopaminergic polymorphisms

BACKGROUND

Understanding the etiopathogenesis of attention-deficit/hyperactivity disorder (ADHD) may necessitate decomposition of the heterogeneous clinical phenotype into more homogeneous intermediate phenotypes. Reinforcement sensitivity is a promising candidate, but the exact nature of the ADHD-reward relation - including how, for whom, and to which ADHD dimensions atypicalities in reward processing are relevant - is equivocal.

METHODS

Aims were to examine, in a carefully phenotyped sample of adolescents (N = 305; Mage = 15.30 years, SD = 1.07; 39.7% girls), whether functional dopaminergic polymorphisms implicated in both reward processing and ADHD (1) are differentially associated with event-related potentials (ERPs) of reward anticipation at distinct levels of ADHD risk (nno risk = 174, nat-risk = 131, ndiagnosed = 83); and (2) moderate the indirect effect of dispositional affectivity on the association between ERPs and ADHD domains.

RESULTS

In adolescents at-risk for or with ADHD, carrying a hypodopaminergic allele was associated with enhanced ERPs of attention allocation to cue and attenuated ERPs of anticipatory attention to feedback. No associations were observed in adolescents not at-risk for or without ADHD. Controlling for age and sex, both the negative indirect effect of positive affectivity (PA) on the association between ERPs and inattention and the positive indirect effect of PA on the association between ERPs and hyperactivity/impulsivity were supported only for those with high activity dopamine transporter (DAT) alleles.

CONCLUSIONS

Reward and affective processing are promising intermediate phenotypes relevant to disentangling ADHD developmental pathways. Consistent with developmental multifinality, through the successive effects of reward anticipation and positive affectivity, functional dopaminergic variants may confer protection against inattention or risk for hyperactivity/impulsivity.

ADHD and ASD symptoms in young males with fragile X syndrome: associations with early trajectories of inhibitory control

Inhibitory control (IC), the ability to suppress inappropriate responses, emerges late in the first year of life and improves across typical development, concurrent with brain maturation. The development of IC is critical to various social-emotional and behavioral functions, with IC difficulties being linked to numerous neurodevelopmental disorders, including attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Fragile X syndrome (FXS) is a single-gene disorder characterized by IC difficulties, and elevated rates of ADHD and ASD, making it a useful model for understanding the early development and consequences of IC. In this longitudinal study, we characterized IC trajectories across multiple time points between 16 and 71 months of age in young males with FXS (n = 79) relative to neurotypical (NT) controls (n=49). To explore the association between behavioral outcomes and IC, we identified a subsample of 50 children with longitudinal IC data and an outcome assessment for ADHD and ASD symptoms at age 5 (FXS: n = 26, NT: n = 24). Results indicated that, compared to their NT peers, young males with FXS exhibit differences in IC as early as 24 months, with group differences increasing through age 5. Additionally, we determined that lower IC levels at 24 months were associated with later ADHD symptoms and a decreasing slope in IC over time was associated with later ASD symptoms in male children with FXS. These findings help refine early developmental phenotypes of FXS and highlight IC as a potential target for early detection and intervention of ASD and ADHD symptoms in male children with FXS.

Effects of Maternal Separation and Subsequent Stress on Behaviors and Brain Monoamines in Rats

Childhood adversity can induce maladaptive behaviors and increase risk for affective disorders, post-traumatic stress disorder, personality disorders, and vulnerability to stress in adulthood. Deprivation of maternal care interrupts brain development through the disturbance of various neurotransmitters, however, the details remain unclear. The features of the symptoms of disorders are largely determined by early stress protocol, genetic characteristics (line), and the sex of the animals. The purpose of current study was (1) to assess behavioral changes in adult Wistar rats of both sexes after early life stress; (2) to determine the levels of monoamines in brain structures involved in the motor, emotional, and social reactions in rats aged 1 and 2 months; and (3) to determine the level of monoamines after physical or emotional stress in adult rats. The rat pups were separated from their dams and isolated from siblings in tight boxes at a temperature of 22-23 °C for 6 h during postnatal days 2-18. The data were processed predominantly using two-way analysis of variance and the Newman-Keys test as the post hoc analysis. The adult rats demonstrated an increase in motor activity and aggressiveness and a decrease in levels of anxiety and sociability. Behavioral disturbances were accompanied by region-, sex-, and age-dependent changes in the levels of monoamines and their metabolites. The dopaminergic and noradrenergic systems were found to be sensitive to psycho-emotional stress.

Transcranial direct current stimulation alters the process of reward processing in children with ADHD: Evidence from cognitive modeling

BACKGROUND

The ventromedial prefrontal cortex (vmPFC) and dorsolateral prefrontal cortex (dlPFC) are the neural underpinnings of reward processing, which is impaired in individuals with attention deficit hyperactivity disorder (ADHD). In the present study, we aimed to explore the impact of the vmPFC and the dlPFC regulation on reward processing.

METHODS

Twenty-six children with ADHD performed the balloon analogue risk-taking task (BART) and chocolate delay discounting task (CDDT) during five different sessions of transcranial direct current stimulation (tDCS), separated by a one-week interval: anodal left dlPFC/cathodal right vmPFC, the reversed electrode positioning, anodal left dlPFC stimulation with extracranial return electrode, anodal right vmPFC stimulation with extracranial return electrodes, and sham stimulation. Four-parameter and constant-sensitivity models were used to model the data.

RESULTS

In the BART, anodal dlPFC/cathodal vmPFC stimulation facilitated conservative decision making, anodal tDCS over dlPFC with extracranial return electrode increased positive beliefs about the explosion of a balloon, and anodal vmPFC/cathodal dlPFC stimulation reduced ongoing learning in the process of decision making. In the CDDT, anodal vmPFC stimulation with extracranial return electrode decreased impatience in the process of the task.

CONCLUSION

These results suggest a role of the left dlPFC and right vmPFC in the outcome of decision making and the process of risky decision making and delay discounting.

Dissociable effects of positive feedback on the capture and inhibition of impulsive behavior in adolescents with ADHD versus typically developing adolescents

The present study investigated how enhancing motivation by delivering positive feedback (a smiley) after a successful trial could affect interference control in adolescents with Attention Deficit Hyperactivity Disorder (ADHD) and in their typically developing (TD) peers. By using a Simon task within the theoretical framework of the "activation-suppression" model, we were able to separately investigate the expression and the inhibition of impulsive motor behavior. The experiment included 19 adolescents with ADHD and 20 TD adolescents in order to explore whether data found in adolescents with ADHD were similar to those found in TD adolescents. Participants performed the Simon task in two conditions: a condition with feedback delivered after each successful trial and a condition with no feedback. The main findings were that increasing motivation by delivering positive feedback increased impulsive response in both groups of adolescents. It also improved the efficiency of impulsive motor action inhibition in adolescents with ADHD but deteriorated it in TD adolescents. We suggest that 1/increased motivation could lead adolescents to favor fast responses even if incorrect, and 2/the differential effect of feedback on the selective suppression of impulsive motor action in both groups could be due to different baseline DA levels.

Effects of methylphenidate on impulsive choice and delay aversion in Lewis rats

Attention-deficit/hyperactivity disorder (ADHD), a common behavioral disorder in children and young adults, is characterized by symptoms of impulsivity, inattention, and hyperactivity. The purpose of this study was to evaluate the Lewis rat strain as a model of ADHD by testing their impulsive choices. Lewis rats were compared to their source strain, the Wistar rat, on an impulsive choice task. Rats completed the tasks on and off methylphenidate, a commonly prescribed medication for ADHD. Off methylphenidate, Lewis rats made more impulsive choices than Wistar rats. Analyses of acquisition of choice behavior suggested that both strains were able to discriminate reward sizes, but Lewis rats still chose the smaller-sooner option more than the larger-later (LL) option when the delays to reward were the same. This may be due to an aversion to the LL lever, which was associated with the longest delays to reward. Higher doses of methylphenidate increased LL choices in Lewis rats but decreased LL choices in Wistar rats. Altogether, these results suggest Lewis rats may be a viable model for ADHD in individuals whose symptoms are characterized by impulsive choices.

Adolescent ADHD and electrophysiological reward responsiveness: A machine learning approach to evaluate classification accuracy and prognosis

We evaluated event-related potential (ERP) indices of reinforcement sensitivity as ADHD biomarkers by examining, in N=306 adolescents (M_age=15.78, SD=1.08), the extent to which ERP amplitude and latency variables measuring reward anticipation and response (1) differentiate, in age- and sex-matched subsamples, (i) youth with vs. without ADHD, (ii) youth at-risk for vs. not at-risk for ADHD, and, in the with ADHD subsample, (iii) youth with the inattentive vs. the hyperactive/impulsive (H/I) and combined presentations. We further examined the extent to which ERP variables (2) predict, in the ADHD subsample, substance use (i) concurrently and (ii) prospectively at 18-month follow-up. Linear support vector machine analyses indicated ERPs weakly differentiate youth with/without (65%) - and at-risk for/not at-risk for (63%) - ADHD but better differentiate ADHD presentations (78%). Regression analyses showed in adolescents with ADHD, ERPs explain a considerable proportion of variance (50%) in concurrent alcohol use and, controlling for concurrent marijuana and tobacco use, explain a considerable proportion of variance (87 and 87%) in, and predict later marijuana and tobacco use. Findings are consistent with the dual-pathway model of ADHD. Results also highlight limitations of a dichotomous, syndromic classification and indicate differences in neural reinforcement sensitivity are a promising ADHD prognostic biomarker.

Inhibitory deficits and symptoms of attention-deficit hyperactivity disorder: How are they related to effortful control?

Separate studies with clinical and community-based samples have identified an association between symptoms of attention-deficit hyperactivity disorder (ADHD) and inhibitory control deficits and ADHD and weak effortful control. We tested whether differences in effortful control explained the associations between ADHD symptoms and inhibitory control deficits, controlling for conduct problems. In a community sample, parents rated ADHD symptoms, conduct problems, effortful control, surgency and negative affect in 77 4-7-year-olds (47 girls), who performed an inhibitory control task. ADHD symptoms, deficient inhibitory control and low effortful control were correlated. Controlling for conduct problems, path analysis showed the ADHD symptoms - inhibitory control link was mediated statistically by effortful control. This focuses attention on cognitive-energetic factors associated with ADHD-related executive deficits.

Examining the structural equation modeling between intrinsic-motivation, emotion regulation and AHDH: the mediating role of problem-solving, time-management, and behavioral-inhibition

Although Executive Functions has been considered as the main correlation of ADHD few studies have examined the effect of EFs on ADHD symptoms, in the samples with ADHD. This study aimed to examine the structure of EFs on ADHD students in a hypothesized model. After careful screening of ADHD among 1368 university students (with stratified and multistage cluster sampling), out of them, 211 students with ADHD diagnosis were selected purposefully. They received scales on their emotion regulation, motivation, adult ADHD, deficits in EFs, and diagnostic interview. Emotion regulation and intrinsic motivation were considered as input; behavioral-inhibition, time-management, and problem-solving were the mediators and ADHD subscales were as the output variables. Results showed that the model adequately fit the data. The model fit indices were χ2 = 27.081, df = 1, CFI = 0.99, GFI = 0.97, and PGFI = 0.02. The direct effects of intrinsic-motivation and emotion-regulation on all three mediators and indirect effects of them to ADHD subscales were significant. Based on the results, time-management mediated the relationship between motivation and emotion regulation and ADHD. Among EFs, emotion-regulation and intrinsic-motivation had fundamental influence to other aspects of EFs factors such as behavioral-inhibition, time-management, problem-solving, and attention deficit/hyperactivity disorder.

Time Perception in Adult ADHD: Findings from a Decade-A Review

Time perception is impaired in adult ADHD. Since the term time perception subsumes different constructs, including time estimation, time reproduction, time production, and duration discrimination, it remains open whether certain domains are more affected than other domains in adult ADHD. The aim of this explorative review is to present the current state of research on time perception in adult ADHD by analysing studies from the past 10 years. A review of the literature addressing adult ADHD time perception, time estimation, and time reproduction was performed. The search strategy was conducted by using the databases "PubMed", "Medline", and "PSYNDEX". The results of the present review indicate that the number of studies on time perception in adult ADHD is very scarce. Moreover, the main investigated domains of time perception in the past decade were time estimation, time reproduction and time management. Whereas some of the found studies were able to demonstrate a distinct deficit in time estimation, time reproduction and time management other studies were unable to demonstrate a clear association between ADHD and time estimation and time reproduction deficits. However, the diagnostic protocols, study design, and methodology varied between studies. Further studies on time estimation and time reproduction need to be carried out.

Altered interaction of physiological activity and behavior affects risky decision-making in ADHD

Background

Adult attention-deficit/hyperactivity disorder (ADHD) is often associated with risky decision-making behavior. However, current research studies are often limited by the ability to adequately reflect daily behavior in a laboratory setting. Over the lifespan impairments in cognitive functions appear to improve, whereas affective functions become more severe. We assume that risk behavior in ADHD arises predominantly from deficits in affective processes. This study will therefore aim to investigate whether a dysfunction in affective pathways causes an abnormal risky decision-making (DM) behavior in adult ADHD.

Methods

Twenty-eight participants with ADHD and twenty-eight healthy controls completed a battery of questionnaires regarding clinical symptoms, self-assessment of behavior and emotional competence. Furthermore, skin conductance responses were measured during the performance in a modified version of the Balloon Analogue Risk Task. A linear mixed-effects model analysis was used to analyze emotional arousal prior to a decision and after feedback display.

Results

Results showed higher emotional arousal in ADHD participants before decision-making (β = -0.12, SE = 0.05, t = -2.63, p < 0.001) and after feedback display (β = -0.14, SE = 0.05, t = -2.66, p = 0.008). Although risky behavior was greater in HC than in ADHD, we found a significant interaction effect of group and anticipatory skin conductance responses regarding the response behavior (β = 107.17, SE = 41.91, t = 2.56, p = 0.011). Post hoc analyses revealed a positive correlation between anticipatory skin conductance responses and reaction time in HC, whereas this correlation was negative in ADHD. Self-assessment results were in line with the objective measurements.

Conclusion

We found altered changes in physiological activity during a risky decision-making task. The results confirm the assumption of an aberrant relationship between bodily response and risky behavior in adult ADHD. However, further research is needed with respect to age and gender when considering physiological activities.

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.

Weak impacts of neuropsychological measures on symptoms of attention deficit hyperactivity disorder in university students

OBJECTIVE

Attention deficit hyperactivity disorder (ADHD) is involved in broad neuropsychological domains, including response inhibition, timing, delay aversion, sustained attention, and working memory. This study aimed to examine the relationship between ADHD symptoms and neuropsychological measures in university students.

METHODS

A total of 167 graduate and undergraduate students participated in the study. Neuropsychological characteristics were comprehensively assessed using stop signal, delay discounting, time discrimination, sensorimotor synchronization, continuous performance, and digit span tasks. ADHD symptoms were assessed using the Japanese version of Conners' ADHD Rating Scale.

RESULTS

ADHD symptoms were significantly correlated with some neuropsychological measures, such as the false alarm rate in the continuous performance task; however, these correlations were not strong. In the multiple regression analyses, models including neuropsychological measures were significantly associated with ADHD symptoms, but the coefficients of determination ranged from 0.06 to 0.08. Thus, most of the variance in ADHD symptoms was not explained by neuropsychological measures.

CONCLUSION

These findings suggest that the impact of each neuropsychological measure on ADHD symptoms was weak in university students, and ADHD symptoms cannot be explained by neuropsychological characteristics, which are currently considered core characteristics of ADHD. In addition, ADHD symptoms assessed by self-rating questionnaire in the non-clinical sample might not reflect the degree of real ADHD severity.

Structural and diffusion-weighted brain imaging predictors of attention-deficit/hyperactivity disorder and its symptomology in very young (4- to 7-year-old) children

The current study aimed to identify the key neurobiology of attention-deficit/hyperactivity disorder (ADHD), as it relates to ADHD diagnostic category and symptoms of hyperactive/impulsive behaviour and inattention. To do so, we adapted a predictive modelling approach to identify the key structural and diffusion-weighted brain imaging measures and their relative standing with respect to teacher ratings of executive function (EF) (measured by the Metacognition Index of the Behavior Rating Inventory of Executive Function [BRIEF]) and negativity and emotion regulation (ER) (measured by the Emotion Regulation Checklist [ERC]), in a critical young age range (ages 4 to 7, mean age 5.52 years, 82.2% Hispanic/Latino), where initial contact with educators and clinicians typically take place. Teacher ratings of EF and ER were predictive of both ADHD diagnostic category and symptoms of hyperactive/impulsive behaviour and inattention. Among the neural measures evaluated, the current study identified the critical importance of the largely understudied diffusion-weighted imaging measures for the underlying neurobiology of ADHD and its associated symptomology. Specifically, our analyses implicated the inferior frontal gyrus as a critical predictor of ADHD diagnostic category and its associated symptomology, above and beyond teacher ratings of EF and ER. Collectively, the current set of findings have implications for theories of ADHD, the relative utility of neurobiological measures with respect to teacher ratings of EF and ER, and the developmental trajectory of its underlying neurobiology.

Understanding Problematic Social Media Use in Adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD): A Narrative Review and Clinical Recommendations

Attention-Deficit/Hyperactivity Disorder (ADHD) is consistently associated with a host of social problems, such as victimization and difficulties in maintaining close friendships. These problems are not limited to offline relations but also manifest in the online social world, as previous research shows that ADHD is associated with problematic use of social media. Given the ubiquitous nature of social media, the goal of the current review is to understand why adolescents with ADHD demonstrate more problematic social media use than their typically developing peers. To this end, we provide a narrative review on the evidence for the link between ADHD and social media use, and consequently present an integrative framework, which encompasses neurobiological mechanisms (i.e., imbalance theory of brain development and dual pathway model of ADHD) and social mechanisms, including influences from peers and parents. We conclude that empirical work shows most consistent evidence for the link between problematic social media use and ADHD (symptoms), while intensity of social media use is also associated with several other behaviors and outcomes. Finally, we hypothesize how existing interventions for ADHD may work on the identified mechanisms and provide at-hand clinical recommendations for therapists working with adolescents with ADHD who exhibit problematic social media use.

Assessment of 'Cool' and 'Hot' Executive Skills in Children with ADHD: The Role of Performance Measures and Behavioral Ratings

Executive dysfunction is an underlying characteristic of Attention Deficit/Hyperactivity Disorder (ADHD). Therefore, this study explored which measures of executive functions (EF) may lead to a better diagnostic prediction and evaluated whether participants were adequately assigned to the ADHD group based on the identified predictors. Seventeen 6- to 10-year-old children with ADHD were matched with 17 typically developing peers (TD) by age, gender, and non-verbal intelligence. Performance-based measures and behavior ratings of 'cool' and 'hot' EF were used. As expected, there was a significant group effect on the linear combination of measures, indicating that children with ADHD showed significant difficulties with EF compared to the TD group. In fact, significant differences were found in measures of short-term and working memory, planning, delay aversion, and EF-related behaviors, as reported by parents and teachers. However, the discriminant function analysis only revealed three significant predictors: the General Executive Composite of the Behavior Rating Inventory of Executive Function (Parent and Teacher Forms) and the Delay of Gratification Task, with 97.1% correct classifications. These findings highlight the importance and contribution of both behavioral ratings and 'hot' measures of EF for the characterization of ADHD in children.

Explaining the Prospective Association of Positive and Negative Parenting Behaviors and Child ADHD Symptoms: Pathways Through Child Executive Function and Reward Responsivity

Objective: Parenting behavior is a well-established correlate of offspring ADHD. However, little is known about how parenting exerts its effects on offspring ADHD symptomatology. We examined whether prospective associations between positive and negative parenting behaviors and child ADHD symptoms are mediated by deficits in child executive function (EF) and reward responsivity (RR). Method: One hundred and thirty-five children with and without ADHD were assessed across two Waves, when children were mean ages 6 and 8 respectively. Children completed tasks on EF, and parents completed questionnaires about their parenting behaviors and their children's RR and ADHD symptoms. Results: Negative parenting behavior at Wave 1 was indirectly associated with offspring ADHD symptoms at Wave 2 via offspring EF. Conclusion: Individual differences in EF, but not RR, during early childhood may constitute a potential pathway by which negative parenting behaviors exerts its effects on subsequent offspring ADHD symptomatology. Treatment implications are discussed.

Joint Consideration of Inhibitory Control and Irritability in Young Children: Contributions to Emergent Psychopathology

Deficits in self-regulation capacity have been linked to subsequent impairment and clinical symptomology across the lifespan. Prior work has identified difficulty regulating angry emotions (i.e., irritability) as a powerful transdiagnostic indicator of current and future clinical concerns. Less is known regarding how irritability intersects with cognitive features of self-regulation, in particular inhibitory control, despite its mental health relevance. A promising avenue for improving specificity of clinical predictions in early childhood is multi-method, joint consideration of irritability and inhibitory control capacities. To advance early identification of impairment and psychopathology risk, we contrast group- and variable-based models of neurodevelopmental vulnerability at the interface of irritability and inhibitory control in contexts of varied motivational and emotional salience. This work was conducted in a longitudinal study of children recruited at well-child visits in Midwestern pediatric clinics at preschool age (N = 223, age range = 3-7 years). Group-based models (clustering and regression of clusters on clinical outcomes) indicated significant heterogeneity of self-regulation capacity in this sample. Meanwhile, variable-based models (continuous multiple regression) evidenced associations with concurrent clinical presentation, future symptoms, and impairment across the broad spectrum of psychopathology. Irritability transdiagnostically indicated internalizing and externalizing problems, concurrently and longitudinally. In contrast, inhibitory control was uniquely associated with attention-deficit/hyperactivity symptoms. We present these findings to advance a joint consideration approach to two promising indicators of neurodevelopmental vulnerability and mental health risk. Models suggest that both emotional and cognitive self-regulation capacities can address challenges in characterizing the developmental unfolding of psychopathology from preschool to early childhood age.

Reduced basal ganglia tissue-iron concentration in school-age children with attention-deficit/hyperactivity disorder is localized to limbic circuitry

Dopamine-related abnormalities in the basal ganglia have been implicated in attention-deficit/hyperactivity disorder (ADHD). Iron plays a critical role in supporting dopaminergic function, and reduced brain iron and serum ferritin levels have been linked to ADHD symptom severity in children. Furthermore, the basal ganglia is a central brain region implicated in ADHD psychopathology and involved in motor and reward functions as well as emotional responding. The present study repurposed diffusion tensor imaging (DTI) to examine effects of an ADHD diagnosis and sex on iron deposition within the basal ganglia in children ages 8-12 years. We further explored associations between brain iron levels and ADHD symptom severity and affective symptoms. We observed reduced iron levels in children with ADHD in the bilateral limbic region of the striatum, as well as reduced levels of iron-deposition in males in the sensorimotor striatal subregion, regardless of diagnosis. Across the whole sample, iron-deposition increased with age in all regions. Brain-behavior analyses revealed that, across diagnostic groups, lower tissue-iron levels in bilateral limbic striatum correlated with greater ADHD symptom severity, whereas lower tissue-iron levels in the left limbic striatum only correlated with anxious, depressive and affective symptom severity. This study sheds light on the neurobiological underpinnings of ADHD, specifically highlighting the localization of tissue-iron deficiency in limbic regions, and providing support for repurposing DTI for brain iron analyses. Our findings highlight the need for further investigation of iron as a biomarker in the diagnosis and treatment of ADHD and sex differences.

School-based group intervention in attention and executive functions: Intervention response and moderators

Objective

This study investigated the effects of a school-based skill-training intervention in attention control and executive functions for pupils with hyperactivity-impulsivity (H-I) and cognitive control (CC) deficits. The main aim was to examine whether the intervention differently influenced H-I and CC, and whether cognitive abilities or conduct problems moderated response to the intervention.

Method

Elementary school pupils from 41 schools participated the study and were divided into an intervention group (n = 71) and a waitlist control group (n = 77). Intervention outcomes were assessed with an inventory assessing executive function difficulties (including H-I and CC) completed by classroom teachers.

Results

Significant intervention effects and positive changes were detected in CC but not in H-I. Significant intervention effects were found mainly among pupils with low levels of conduct problems.

Conclusions

The results suggest that a skill-training intervention has specific positive effects on CC, but conduct problems may diminish response to intervention.

Mind-Wandering and Childhood ADHD: Experimental Manipulations across Laboratory and Naturalistic Settings

The conceptual overlap between mind-wandering and attention-deficit/hyperactivity disorder (ADHD)-related impairments is considerable, yet little experimental research examining this overlap among children is available. The current study aims to experimentally manipulate mind-wandering among children with and without ADHD and examine effects on task performance. Participants were 59 children with ADHD and 55 age-matched controls. Participants completed a novel mind-wandering sustained attention to response task (SART) that included non-self-referential and self-referential stimuli to experimentally increase self-referential mind-wandering, reflected by increases in reaction time variability (RTV) following self-referential stimuli. The ADHD group participated in a classroom study with analogue conditions aimed at encouraging self-referential future-oriented thinking (free play/movie before and after class work) compared to a control condition (newscast) and a cross-over methylphenidate trial. The significant interaction between ADHD status and self-referential stimuli on SART performance indicated that self-referential stimuli led to greater RTV among children with ADHD (within-subject d = 1.29) but not among controls. Methylphenidate significantly reduced RTV among youth with ADHD across self-referential (d = 1.07) and non-self-referential conditions (d = 0.72). In the ADHD classroom study, the significant interaction between mind-wandering condition and methylphenidate indicated that methylphenidate led to higher work completion (ds > 5.00), and the free-play mind-wandering condition had more consistent detrimental effects on productivity (ds ≥ 1.25) than the movie mind-wandering condition. This study is the first to manipulate mind-wandering and assess effects among children with ADHD using a behavioral task. Results provide evidence that children with ADHD are uniquely susceptible to mind-wandering interference.

The Association between Sleep Problems and Neuropsychological Deficits in Medication-naïve Children with ADHD

BACKGROUND

Children with ADHD are reported to have sleep problems and neuropsychological deficits, but studies examining a potential association between the two are scarce and the use of varying methodology can complicate conclusions.

PARTICIPANTS

A clinical sample of 59 medication-naïve children with ADHD between the ages of 6 and 14 years (71% male).

METHODS

Children underwent polysomnography and multiple sleep latency test, and parent rated sleep habits on the Children's Sleep Habits Questionnaire. Children also completed an extensive neuropsychological battery of executive function and delay aversion tasks, and parents and teachers rated executive function behavior on the Behavior Rating Inventory of Executive Function. Linear regression analyses were conducted with each of the neuropsychological outcomes included as the outcome variable and the sleep parameters as the predictor variables.

RESULTS

The correlations between sleep and neuropsychological outcomes were generally modest, but some sleep parameters (primarily sleep stages and sleep latencies) were associated with objectively and subjectively measured executive function and delay aversion.

CONCLUSIONS

Using objective and subjective gold standard assessment procedures this study supports a (modest) association between sleep and neuropsychological function in children with ADHD.

Decision-making and Risky Behavior in Individuals with Attention-Deficit/Hyperactivity Disorder: A 10-year Longitudinal Study

We assessed 85 children with Attention-Deficit/Hyperactivity Disorder (ADHD) and 50 typically developing children (TD) (M_age = 11.59, 57.8% boys) with the Hungry Donkey Task (HDT) at baseline and 2-year follow-up, and the Iowa Gambling Task at 10-year follow-up (75% retention). Improvement in the proportion of advantageous choices was observed from two- to 10-year follow-up, but the ADHD group improved less and was outperformed by the TD group at the 10-year follow-up. More advantageous choices on the HDT at baseline predicted less risky behavior at 10-year follow-up. Male sex and more inattentive or externalizing symptoms at baseline predicted more risky behavior.

Studying Motivation in ADHD: The Role of Internal Motives and the Relevance of Self Determination Theory

OBJECTIVE

Motivation is what moves us to act, what engages us in goal-directed behavior. The Self Determination Theory (SDT) is a motivational framework conceptualizing motivation-or internal motives-as a continuum of motivation qualities fueled by satisfaction of the three basic psychological needs Autonomy, Relatedness, and Competence. ADHD has been associated with motivational alterations that contribute to academic difficulties. However, ADHD theories and research are mainly focused on the effects of reinforcement on behavior, with little attention for the broader definition of motivation, that is, internal motives. Therefore, the main objective here was to introduce the SDT as theoretical framework within which we can develop relevant research questions about motivation in the field of ADHD.

METHOD

To this end, we (i) present the SDT as a comprehensive motivational framework, and (ii) describe current motivation-related ADHD theories and research.

RESULTS

Based on this, we suggest how SDT can be used as a guiding framework in generating relevant research questions that can help broaden our understanding of the role motivation plays in individuals with ADHD.

CONCLUSION

We conclude that ADHD research on motivation would benefit from (i) including internal motives as potential key mediators in the relation between environmental factors and behavior/symptoms; (ii) studying potential negative effects of external reinforcers intrinsic motivation, affect, and well-being. Finally, we conclude that this framework carries value for further development of clinical interventions for those with ADHD.

Parental Attitudes and Beliefs toward Attention Deficit Hyperactivity Disorder in Prince Sultan Military Medical City, Riyadh City

The present study was designed to investigate attitudes and beliefs among parents of patients with attention deficit hyperactivity disorder (ADHD), with regard to symptoms, causes, prognosis, and management. The study was of a cross-sectional descriptive design including 283 parents of patients with ADHD (preschool, primary school, and adolescent). It was conducted at child and adolescent outpatient clinics in Prince Sultan Military Medical City, Riyadh to assess parents’ knowledge, attitudes, treatments, and beliefs regarding ADHD. Among 283 parents, 59.8% believed that diet could improve ADHD symptoms. Approximately 75% of parents believed that ADHD is a form of misbehavior rather than a neurodevelopmental disorder, whereas 55.6% believed that ADHD is a genetic disease. In total, 89% of parents wanted to treat their children by receiving specialist advice and recommendations. A significant and nonsignificant correlation between gender and preschool and primary school was recorded, respectively. However, a positive correlation was recorded between age and caregiver’s education in adolescents. Since parents’ attitudes and perceptions were poor overall, the mismanagement of ADHD was noticed. Furthermore, government-level media campaigns should be implemented to enhance parents’ knowledge and debunk myths in order to improve ADHD management.