A critical appraisal of the role of neuropsychological deficits in preschool ADHD

The Utility of a Novel Neuropsychological Measurement to Analyze Event-Related Attentional Behaviors among Young Children with Attention Deficit Hyperactivity Disorder-a Pilot Study

OBJECTIVE

The identification and diagnosis of children with attention deficit hyperactivity disorder (ADHD) traits is challenging during the preschool stage. Neuropsychological measures may be useful in early assessments. Furthermore, analysis of event-related behavior appears to be an unmet need for clinical treatment planning. Conners' Kiddie Continuous Performance Test (K-CPT) is the most popular well-established neuropsychological measurement but lacks event markers to clarify the heterogeneous behaviors among children. This study utilized a novel commercially available neuropsychological measure, the ΣCOG, which was more game-like and provided definite event markers of individual trial in the test.

METHODS

Thirty-three older preschool children (14 were diagnosed with ADHD, mean age: 66.21 ± 5.48 months; 19 demonstrated typical development, mean age: 61.16 ± 8.11 months) were enrolled and underwent comprehensive medical and developmental evaluations. All participants underwent 2 versions of neuropsychological measures, including the K-CPT, Second Edition (K-CPT 2) and the ΣCOG, within a short interval.

RESULTS

The study indicated the omissions and response time scores measured in this novel system correlated with clinical measurement of the behavioral scales in all participants and in the group with ADHD; additionally, associations with the traditional K-CPT 2 were observed in commissions and response time scores. Furthermore, this system provided a within-task behavioral analysis that identified the group differences in the specific trial regarding omission and commission errors.

CONCLUSIONS

This innovative system is clinically feasible and can be further used as an alternative to the K-CPT 2 especially in research by revealing within-task event-related information analysis.

The effect of neurofeedback training combined with computer cognitive games on the time perception, attention, and working memory in children with ADHD

OBJECTIVE

The purpose of this study was to examine the effect of neurofeedback (NF) based on quantitative electroencephalography (QEEG) and SmartMind game on the time perception, attention, and working memory of children with Attention Deficit/Hyperactivity Disorder (ADHD) through an experimental design.

METHOD

Using a purposive sampling method, 32 male students diagnosed with ADHD were selected and then randomly assigned to an experimental group and a control group. The experimental group received the treatment (NF + SmartMind) for 30 weekly sessions. Children's performances on a time perception test, a Continuous Performance Test (CPT), and a Wechsler working memory test (WISC) were examined before and after the intervention.

RESULTS

A significant difference was observed between the mean scores of the pretest and post-test for the experimental group, implying that NF training improved short-time perception and long-time perception attention in CPT test: omission error component, Correct Response component, and working memory: Visual forward component. However, the treatment did not have a significant effect on the commission error component (CPT), working memory in terms of the visual reverse, auditory reverse, and auditory forward components.

CONCLUSION

NF combined with computer cognitive games (CCGs) can improve time perception, attention, and working memory in children with ADHD.

Association between relative age at school and persistence of ADHD in prospective studies: an individual participant data meta-analysis

BACKGROUND

The youngest children in a school class are more likely than the oldest to be diagnosed with ADHD, but this relative age effect is less frequent in older than in younger school-grade children. However, no study has explored the association between relative age and the persistence of ADHD diagnosis at older ages. We aimed to quantify the association between relative age and persistence of ADHD at older ages.

METHODS

For this meta-analysis, we searched MEDLINE, Embase, CINAHL, PsycINFO, and PubPsych up to April 1, 2022, with terms related to "cohort" and "ADHD" with no date, publication type, or language restrictions. We gathered individual participant data from prospective cohorts that included at least ten children identified with ADHD before age 10 years. ADHD was defined by either a clinical diagnosis or symptoms exceeding clinical cutoffs. Relative age was recorded as the month of birth in relation to the school-entry cutoff date. Study authors were invited to share raw data or to apply a script to analyse data locally and generate anonymised results. Our outcome was ADHD status at a diagnostic reassessment, conducted at least 4 years after the initial assessment and after age 10 years. No information on sex, gender, or ethnicity was collected. We did a two-stage random-effects individual participant data meta-analysis to assess the association of relative age with persistence of ADHD at follow-up. This study was registered with PROSPERO, CRD42020212650.

FINDINGS

Of 33 119 studies generated by our search, we identified 130 eligible unique studies and were able to gather individual participant data from 57 prospective studies following up 6504 children with ADHD. After exclusion of 16 studies in regions with a flexible school entry system that did not allow confident linkage of birthdate to relative age, the primary analysis included 41 studies in 15 countries following up 4708 children for a period of 4 to 33 years. We found that younger relative age was not statistically significantly associated with ADHD persistence at follow-up (odds ratio 1·02, 95% CI 0·99-1·06; p=0·19). We observed statistically significant heterogeneity in our model (Q=75·82, p=0·0011, I2=45%). Participant-level sensitivity analyses showed similar results in cohorts with a robust relative age effect at baseline and when restricting to cohorts involving children with a clinical diagnosis of ADHD or with a follow-up duration of more than 10 years.

INTERPRETATION

The diagnosis of ADHD in younger children in a class is no more likely to be disconfirmed over time than that of older children in the class. One interpretation is that the relative age effect decreases the likelihood of children of older relative age receiving a diagnosis of ADHD, and another is that assigning a diagnostic label of ADHD leads to unexplored carryover effects of the initial diagnosis that persist over time. Future studies should be conducted to explore these interpretations further.

FUNDING

None.

Executive function profiles of preschool children with autism spectrum disorder and attention-deficit/hyperactivity disorder: A systematic review

Background

Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) are both associated with differences in Executive Functioning (EF). There is lack of clarity around the specificity or overlap of EF differences in early childhood when both disorders are first emerging.

Method

This systematic review aims to delineate preschool EF profiles by examining studies comparing the EF profiles of children with and without ASD or ADHD. Five electronic databases were systematically searched (last search in May 2022) to identify published, quantitative studies of global and specific EF (Inhibition, Shifting, Working Memory (WM), Planning and Attentional Control), comparing children aged 2-6 with a diagnosis of ASD or ADHD to peers without ASD or ADHD.

Results

Thirty-one empirical studies (10 ADHD and 21 ASD studies) met criteria for inclusion. EF profiles in preschool ASD were characterised by consistent Shifting, and, in most cases, Inhibition impairments. ADHD studies consistently reported impairments in Inhibition and Planning, and in most cases WM. Findings with regards to sustained Attention and Shifting in ADHD and WM and Planning in ASD were mixed.

Conclusions

Overall, current evidence indicates overlap but also some specificity in EF impairments in preschool ASD and ADHD. There were differences in the degree to which individual domains were impaired, with Shifting more consistently impaired in ASD, and Inhibition, WM and Planning in ADHD. Methodological issues and differences in methods of outcome measurement could potentially underlie mixed findings, as informant-based measures revealed more robust EF impairments than laboratory-based tasks.

Evidence of emotion dysregulation as a core symptom of adult ADHD: A systematic review

Attention Deficit Hyperactivity Disorder (ADHD) is a developmental disorder, with an onset in childhood, that accompanies the person throughout their life, with prevalence between 3 and 5% in adults. Recent studies point towards a fourth core symptom of the disorder related to the emotional information processing that would explain the repercussions that ADHD has on the social, academic, and professional life of the people affected. This review aims to describe emotion dysregulation features as well as the brain activity associated in adults with ADHD. A search of the scientific literature was launched in specialized databases: PsycInfo, Medline, Eric, PsycArticle, Psicodoc and Scopus, following PRISMA guidelines. Twenty-two articles met the inclusion criteria: (a) an ADHD clinical diagnosis, (b) participants over 18 years old, (c) emotion regulation measurement, (d) empirical studies, and (c) in English. Due to the heterogeneity of the studies included, they were classified into three sections: measures and features of emotion regulation (ER) in people with ADHD, neurological and psychophysiological activity related to ER, and treatments. The studies found that meet the selection criteria are scarce and very heterogeneous both in aims and in sample features. Adults with ADHD show a more frequent use of non-adaptive emotion regulation strategies compared to people without ADHD symptoms. Moreover, emotion dysregulation was associated with symptom severity, executive functioning, psychiatric comorbidities, and even with criminal conviction. Different patterns of brain activity were observed when people with and without ADHD were compared. These results may suggest that psychopharmacological treatments as well as behavioral therapies could be useful tools for improving emotional difficulties in adult ADHD.

Therapeutic and mechanistic intervention of vitamin D in neuropsychiatric disorders

Vitamin D deficiency is believed to affect between 35 and 55% of the world's population, making it a hidden pandemic. In addition to its role in bone and calcium homeostasis, vitamin D has also been linked in preclinical and clinical research to brain function. These outcomes have also been used for a variety of neuropsychiatric and neurodevelopmental problems. Nevertheless, these individuals are more prone to develop signs of cognitive decline. This review will emphasize the association between vitamin D and neuropsychiatric illnesses such as autism, schizophrenia, depression, and Attention Deficit Hyperactivity Disorder (ADHD). While numerous research show vitamin D's essential role in cognitive function in neuropsychiatric illnesses, it is too early to propose its effect on cognitive symptoms with certainty. It is necessary to conduct additional research into the associations between vitamin D deficiency and cognitive abnormalities, particularly those found in autism, schizophrenia, depression, and ADHD, to develop initiatives that address the pressing need for novel and effective preventative therapeutic strategies.

Incremental Validity of Multi-Method and Multi-Informant Evaluations in the Clinical Diagnosis of Preschool ADHD

OBJECTIVES

This study investigated the discriminative validity of various single or combined measurements of electroencephalogram (EEG) data, Conners' Kiddie Continuous Performance Test (K-CPT), and Disruptive Behavior Disorder Rating Scale (DBDRS) to differentiate preschool children with ADHD from those with typical development (TD).

METHOD

We recruited 70 preschoolers, of whom 38 were diagnosed with ADHD and 32 exhibited TD; all participants underwent the K-CPT and wireless EEG recording in different conditions (rest, slow-rate, and fast-rate task).

RESULTS

Slow-rate task-related central parietal delta (1-4 Hz) and central alpha (8-13 Hz) and beta (13-30 Hz) powers between groups with ADHD and TD were significantly distinct (p < .05). A combination of DBDRS, K-CPT, and specific EEG data provided the best probability scores (area under curve = 0.926, p < .001) and discriminative validity to identify preschool children with ADHD (overall correct classification rate = 85.71%).

CONCLUSIONS

Multi-method and multi-informant evaluations should be emphasized in clinical diagnosis of preschool ADHD.

Do Executive Dysfunction, Delay Aversion, and Time Perception Deficit Predict ADHD Symptoms and Early Academic Performance in Preschoolers

Children with attention deficit/hyperactivity disorder (ADHD) are commonly observed to have learning difficulties. This study examined how three neuropsychological constructs—executive dysfunction, delay aversion, and time perception—were associated with ADHD symptoms and early academic performance in preschoolers at risk of ADHD. One hundred and thirty-one preschoolers (70 boys, 53%) aged 4 to 6 (M = 5.31 years) were assessed on their ADHD-related behaviors, neuropsychological functioning, word reading, and math abilities at two time points one year apart. Factor analysis indicated that inhibitory and attentional control deficit, delay aversion, and time perception/working memory deficit were three dissociable factors. Among the three factors, inhibitory and attentional control measured at Time 1 was the strongest predictor of ADHD symptoms at both Time 1 and Time 2. Time perception was closely related to working memory, and they predicted word reading and numeration across time most strongly among other neuropsychological constructs. Our findings suggested that inhibitory and attentional control, delay aversion, and time perception are dissociable neuropsychological deficits underlying ADHD symptoms in preschoolers. Poor time perception may serve as a marker for the early identification of preschoolers with potential learning problems, and a possible target of intervention for ADHD.

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.

Attention-deficit hyperactivity disorder and executive dysfunction in preschool children. A comparison of NEPSY and BRIEF-P assessments

OBJECTIVE

The aim of the study was to explore prevalence, interrelations and accuracy of assessing psychopathology, intelligence, and executive functions (EF) in preschool children with ADHD (age 2.1-6.5 years).

METHOD

We prospectively investigated 115 preschool outpatient children (91 boys, 24 girls, aged 4.3±1.0 years) with the clinical diagnosis of ADHD. Assessment included clinical history, background, psychosocial problems (CBCL, C-TRF), ADHD (DISYPS external ratings), cognitive performance (WPPSI-III, K-ABC), and executive functions (BRIEF-P, NEPSY).

RESULTS

We found a high frequency of dysexecutive problems in up to 64 % in the parental BRIEF-P assessments, up to 62 % in the BRIEF-P teachers' assessments, and 62 % in the NEPSY functional assessments. Parental and teachers' BRIEF-P scores were only correlated in one subscale, inhibition, and NEPSY and BRIEF-P were not correlated at all. It was found that 42.5 % of the children with noticeable findings had agreeing results in all three, and another 45 % in two tests.

CONCLUSIONS

About 2/3 of the ADHD preschool children had detectable EF dysfunctions. In order to assess dysexecutive problems, multi-method testing is mandatory.

Updates in technology-based interventions for attention deficit hyperactivity disorder

PURPOSE OF REVIEW

Technological advancement has led to the development of novel treatment approaches for attention deficit hyperactivity disorder (ADHD). This review aims to review recent studies which employ the use of technology to treat ADHD, with particular focus on studies published during a 1-year period from February 2019 to February 2020.

RECENT FINDINGS

Most recent studies involved children aged 12 years and below. Interventions included cognitive training through games, neurofeedback and a combination of several approaches. More novel approaches included trigeminal nerve stimulation and brain-computer interface, and studies had utilized technology such as X-box Kinect and eye tracker. There was a shift towards delivering intervention at home and in school, enabled by technology. The study outcomes were variable and mainly included executive functioning measures and clinical ratings. These interventions were generally safe with few reported adverse events.

SUMMARY

Technology has enabled interventions to be delivered outside of the clinic setting and presented an opportunity for increased access to care and early intervention. Better quality studies are needed to inform on the efficacy of these interventions.

Using Repeated-Measures Data to Make Stronger Tests of the Association between Executive Function Skills and Attention Deficit/Hyperactivity Disorder Symptomatology in Early Childhood

Theoretical models of Attention deficit/hyperactivity disorder (ADHD) have long implicated executive function (EF) skills as contributing to the etiology, maintenance, and changes in ADHD symptomatology over time. Although there is interest making within-person inferences (i.e., deficits in EF skills give rise to ADHD behaviors), most of the evidence has been derived from studies that conflated between- and within-person sources of variance. Here, we use repeated-measures data to test within-person association between EF skills and ADHD behaviors. Participants included 1160 children from the Family Life Project, an ongoing prospective longitudinal study of child development in low-income, nonmetropolitan communities. We tested the magnitude of the association between EF skills and ADHD behaviors when children were 3, 4, and 5 years old. Consistent with meta-analyses, unadjusted bivariate associations between EF and ADHD (which reflect combined between- and within-person variation) were of moderate magnitude (rs = -0.20 to -0.30). However, after controlling for all time-invariant, between-person sources of variation, the within-person associations between EF skills and ADHD behaviors were weak (βs - 0.04 to -0.05, ps = 0.01). These results suggest that EF skills may contribute less prominently to ADHD behaviors in early childhood than is commonly assumed and provoke broader questions about developmental models of ADHD.

Does ADHD worsen inhibitory control in preschool children born very premature and/or with very low birth weight?

INTRODUCTION

Deficits in executive functioning, especially in inhibitory control, are present in children born very premature and/or with very low birth weight (VP/VLBW) and in children with attention-deficit/hyperactivity disorder (ADHD).

OBJECTIVE

To evaluate whether ADHD imposes additional inhibitory control (IC) deficits in preschoolers born VP/VLBW.

METHODS

79 VP/VLBW (4 to 7 years) children were assessed for ADHD using the Schedule for Affective Disorders and Schizophrenia for School Aged Children - Present and Lifetime Version (K-SADS-PL). IC was measured with Conners' Kiddie Continuous Performance Test (K-CPT 2) and the Behavior Rating Inventory of Executive Function - Preschool Version (BRIEF-P).Results: No significant differences were found between ADHD (n = 24) and non-ADHD children (n = 55) for any of the measures (p = 0.062 to p = 0.903). Both groups had deficits in most K-CPT 2 scores compared to normative samples, indicating poor IC and inconsistent reaction times.

CONCLUSIONS

ADHD does not aggravate IC deficits in VP/VLBW children. Either neuropsychological tasks and parent reports of executive functions (EFs) may not be sensitive enough to differentiate VP/VLBW preschoolers with and without ADHD, or these children's EFs are already so impaired that there is not much room for additional impairments imposed by ADHD.

Psychometric properties of the Teenage Executive Functioning Inventory (TEXI): A freely available questionnaire for assessing deficits in working memory and inhibition among adolescents

The Childhood Executive Functioning Inventory (CHEXI) and the Adult Executive Functioning Inventory (ADEXI) are reliable and valid rating instruments for assessing working memory and inhibitory control. However, a teenage version of this instrument has not been available, and the aim of the present study was therefore to investigate the psychometric properties of the Teenage Executive Functioning Inventory (TEXI). After interviewing both researchers/clinicians and adolescents themselves, a questionnaire with 20 items was created. Data from adolescents age 13-19 years (n = 302) and their parents were thereafter collected. Factor analysis showed that the TEXI has two clear factors: working memory and inhibition. Further, the TEXI was shown to have high reliability in terms of internal consistency (≥ .85), split-half reliability (≥ .81) and inter-rater reliability between self-ratings and parent ratings (.82). In sum, the TEXI is a reliable questionnaire for measuring working memory and inhibition in adolescents. The two versions of the TEXI are presented in the appendices of this paper and they will be freely available on the Internet.

Psychometric properties of Persian version of the Barkley deficits in executive functioning scale-children and adolescents

The Barkley Deficits in Executive Functioning Scale-Children and Adolescents (BDEFS-CA) is an empirically based tool for evaluating clinically significant dimensions of child and adolescent executive functioning. The present study examined the psychometric properties of Persian version of the BDEFS-CA Long Form parent-report in children and adolescents aged 6-18 years old (n = 2,295, 51% girls). The results of confirmatory factor analysis (CFA) consistently underscored a five-factor structure (self-management to time, self-organization/problem solving, self-restraint, self-motivation and self-regulation of emotion), resembling the original factor structure, in Persian language. Additionally, Results showed that Persian version of the BDEFS-CA Long Form demonstrated high internal consistency and test-retest reliabilities. Convergent validity with Childhood Executive Functioning Inventory (CHEXI) and divergent validity between normal and clinical groups were good. Overall, findings provide support for the validity and reliability Persian version of the BDEFS-CA Long Form, which can be used to assess executive dysfunction in daily life activities.

Longitudinal Neuropsychological Assessment in Two Elderly Adults With Attention-Deficit/Hyperactivity Disorder: Case Report

The neuropsychological deficits in attention-deficit/hyperactivity disorder (ADHD) may present clinical features similar to mild and/or major neurocognitive disorder and may act as a confounding factor, making it difficult to detect cognitive decline. In this paper, we present the results of longitudinal neuropsychological evaluations in two elderly women with ADHD. Three neuropsychological assessments were performed in two women with ADHD (60 and 77 years old) between 2010 and 2013 at intervals varying from 12 to 15 months. We used structural magnetic resonance imaging to rule out significant abnormalities that could account for cognitive impairment. The results showed two different cognitive profiles with fluctuations in performance over these 2 years, sometimes with improvement and sometimes with decline of some functions such as attention, memory, inhibitory control, and reaction time. To minimize confounding aspects of these fluctuations in clinical practice, we used a longer follow-up with the application of a reliable change index and a minimum of three spaced assessments to provide a more consistent baseline cognitive profile. Our findings did not indicate a consistent cognitive decline, suggesting a less pessimistic perspective about cognitive impairments that could be a prodrome of ADHD-related dementia.

Behavior problems and executive function impairments in preterm compared to full term preschoolers

BACKGROUND

Children born preterm (PT) are at high risk for behavior problems and deficits in executive function (EF), a set of cognitive processes that guide goal-directed behaviors. Behavior differences have been found as early as 2 years in PT children; EF differences have been found in infancy. Whether behavior problems and EF deficits co-occur at young ages has not been fully investigated.

AIMS

To determine whether (1) PT children have more behavior problems and EF impairment than full term (FT) children and (2) larger proportions of PT children show behavior problems or EF impairments.

DESIGN/METHODS

PT (≤34 wks, n = 82) and FT (n = 79) preschoolers (mean age 4.4 years) completed an EF battery. Parents completed rating scales of behavior problems and EF skills. Mean scores and proportions with impairment were compared between groups. Logistic regression predicting to impairment defined odds ratios for PT/FT groups.

RESULTS

PT compared to FT had more problems on most behavior and EF scales and poorer EF scores on all tasks and greater proportion with impairments on most behavior scales, all EF ratings, and all EF tasks, p < .05. PT had elevated odds for impaired performance-based EF, parent-rated EF and CBCL scores compared to FT, p < .05. Within the PT group, EF impairments were twice as common as behavior impairment.

CONCLUSIONS

We recommend early identification of EF impairments in PT children. Future research should evaluate whether EF impairments serve as better early markers for later functional difficulties compared to behavior problems, as well as targets for intervention.