Working memory control deficit in kindergarten ADHD children

Ocular and neural genes jointly regulate the visuospatial working memory in ADHD children

OBJECTIVE

Working memory (WM) deficits have frequently been linked to attention deficit hyperactivity disorder (ADHD). Despite previous studies suggested its high heritability, its genetic basis, especially in ADHD, remains unclear. The current study aimed to comprehensively explore the genetic basis of visual-spatial working memory (VSWM) in ADHD using wide-ranging genetic analyses.

METHODS

The current study recruited a cohort consisted of 802 ADHD individuals, all met DSM-IV ADHD diagnostic criteria. VSWM was assessed by Rey-Osterrieth complex figure test (RCFT), which is a widely used psychological test include four memory indexes: detail delayed (DD), structure delayed (SD), structure immediate (SI), detail immediate (DI). Genetic analyses were conducted at the single nucleotide polymorphism (SNP), gene, pathway, polygenic and protein network levels. Polygenic Risk Scores (PRS) were based on summary statistics of various psychiatric disorders, including ADHD, autism spectrum disorder (ASD), major depressive disorder (MDD), schizophrenia (SCZ), obsessive compulsive disorders (OCD), and substance use disorder (SUD).

RESULTS

Analyses at the single-marker level did not yield significant results (5E-08). However, the potential signals with P values less than E-05 and their mapped genes suggested the regulation of VSWM involved both ocular and neural system related genes, moreover, ADHD-related genes were also involved. The gene-based analysis found RAB11FIP1, whose encoded protein modulates several neurodevelopment processes and visual system, as significantly associated with DD scores (P = 1.96E-06, Padj = 0.036). Candidate pathway enrichment analyses (N = 53) found that forebrain neuron fate commitment significantly enriched in DD (P = 4.78E-04, Padj = 0.025), and dopamine transport enriched in SD (P = 5.90E-04, Padj = 0.031). We also observed a significant negative relationship between DD scores and ADHD PRS scores (P = 0.0025, Empirical P = 0.048).

CONCLUSIONS

Our results emphasized the joint contribution of ocular and neural genes in regulating VSWM. The study reveals a shared genetic basis between ADHD and VSWM, with GWAS indicating the involvement of ADHD-related genes in VSWM. Additionally, the PRS analysis identifies a significant relationship between ADHD-PRS and DD scores. Overall, our findings shed light on the genetic basis of VSWM deficits in ADHD, and may have important implications for future research and clinical practice.

Are Parent- and Teacher-Reported Executive Function Difficulties Associated With Parenting Stress for Children Diagnosed With ADHD?

Objective: To examine the relationship between parenting stress and parent- and teacher-reported executive function difficulties (EFDs) for childhood ADHD. Method: A secondary analysis using linear regression was conducted on parent- and teacher-completed Behavior Rating Inventory of Executive Function and Parenting Stress Indexes for 5- to 12-year-olds (n = 243) with ADHD. Results: The linear combination of teacher- and parent-reported EFDs accounted for 49% of the variance in child-related parenting stress. Teacher-reported school-based EFDs were relatively inconsequential, having accounted for only 3% of this variance. This stress is best explained by EFDs with emotional control in the school environment and parent-reported EFDs with emotional control, inhibit, monitor, and shift. Conclusion: Parent-reported EFDs, and less so school-based EFDs, are related to parenting stress, but only in regard to EFDs likely underpinning behavioral outbursts and those likely underpinning the daily hassles of providing specialized care to children with ADHD.

The relationship of working memory and inhibition with different number knowledge skills in preschool children

The purpose of this study was to analyze the contribution of specific executive function (EF) components to different number knowledge skills. A sample of 143 children attending the last year of preschool educational services (M_age = 65.01 months, SD = 3.57) were tested on five number knowledge tasks from the Numerical Intelligence Battery and four EF tasks assessing working memory (WM) and inhibition. First, we examined the interrelationship between different number skills; the results suggested that the relationship between basic informal skills (set comparison and number sequence) and formal skills (seriation of Arabic numerals and number comparison) was mediated by the ability to link sets to numerals. Next, we explored the contribution of WM and inhibition to different number knowledge skills. The structural equation model showed that WM and inhibition were differentially related to specific number knowledge skills. Specifically, WM predicted most components of number knowledge, including the two basic informal skills and the number comparison, whereas inhibition contributed to the seriation of Arabic numerals. The ability to link sets to numerals was predicted only by number sequence, not by EF components.

Arousal and Executive Alterations in Attention Deficit Hyperactivity Disorder (ADHD)

Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioral disorder in childhood and can significantly affect a child's personal and social development and academic achievement. Taking into account the model of attentional networks proposed by Posner et al., the aim of the present study was to review the literature regarding two main explicative models of ADHD, i.e., the inhibition model and the cognitive-energetic model, by discussing behavioral and neurological evidence of both models and the limitations of each model. The review highlights evidence that favors the energetic model and points to an unstable arousal as a potential pathogenetic factor in ADHD.

Executive functioning and neurodevelopmental disorders in early childhood: a prospective population-based study

BACKGROUND

Executive functioning deficits are common in children with neurodevelopmental disorders. However, prior research mainly focused on clinical populations employing cross-sectional designs, impeding conclusions on temporal neurodevelopmental pathways. Here, we examined the prospective association of executive functioning with subsequent autism spectrum disorder (ASD) traits and attention-deficit/hyperactivity disorder (ADHD) traits.

METHODS

This study included young children from the Generation R Study, a general population birth cohort. The Brief Rating Inventory of Executive Function-Preschool Version was used to assess parent-reported behavioral executive functioning when the children were 4 years old. ASD traits were assessed at age 6 (n = 3938) using the parent-reported Social Responsiveness Scale. The Teacher Report Form was used to assess ADHD traits at age 7 (n = 2749). Children with high scores were screened to determine possible clinical ASD or ADHD diagnoses. We were able to confirm an ASD diagnosis for n = 56 children by retrieving their medical records and established an ADHD diagnosis for n = 194 children using the Diagnostic Interview Schedule for Children-Young Child version (DISC-YC). Data were analyzed using hierarchical linear and logistic regressions.

RESULTS

Impaired executive functioning was associated with more ASD and ADHD traits across informants (for ASD traits and diagnoses: β = 0.33, 95% CI [0.30-0.37]; OR = 2.69, 95% CI [1.92-3.77], respectively; for ADHD traits and diagnoses: β = 0.12, 95% CI [0.07-0.16]; OR = 2.32, 95% CI [1.89-2.85], respectively). Deficits in all subdomains were associated with higher levels of ASD traits, whereas only impaired inhibition, working memory, and planning/organization were associated with more ADHD traits.

CONCLUSIONS

The findings of the current study suggest a graded association of executive functioning difficulties along the continuum of ASD and ADHD and that problems in executive functioning may be a precursor of ASD and ADHD traits from an early age onwards.

Neuropsychological Profile Related with Executive Function of Chinese Preschoolers with Attention-Deficit/Hyperactivity Disorder: Neuropsychological Measures and Behavior Rating Scale of Executive Function-Preschool Version

Background:

Previous studies have found that schoolchildren with attention-deficit/hyperactivity disorder (ADHD) showed difficulties in neuropsychological function. This study aimed to assess neuropsychological function in Chinese preschoolers with ADHD using broad neuropsychological measures and rating scales and to test whether the pattern and severity of neuropsychological weakness differed among ADHD presentations in preschool children.

Methods:

The 226 preschoolers (163 with ADHD and 63 controls) with the age of 4–5 years were included and assessed using the Behavior Rating Scale of Executive Function-Preschool Version (BRIEF-P) and a series of tests to investigate neuropsychological function.

Results:

Preschoolers with ADHD showed higher scores in all domains of the BRIEF-P (inhibition: 30.64 ± 5.78 vs.20.69 ± 3.86, P < 0.001; shift: 13.40 ± 3.03 vs.12.41 ± 2.79, P = 0.039; emotional control:15.10 ± 3.53 vs.12.20 ± 2.46, P < 0.001; working memory: 28.41 ± 4.99 vs.20.95 ± 4.60, P < 0.001; plan/organize: 17.04 ± 3.30 vs.13.29 ± 2.40, P < 0.001) and lower scores of Statue (23.18 ± 7.84 vs.28.27 ± 3.18, P = 0.001), Word Generation (15.22 ± 6.52 vs.19.53 ± 7.69, P = 0.025), Comprehension of Instructions (14.00 ± 4.44 vs.17.02 ± 3.39, P = 0.016), Visuomotor Precision (P < 0.050), Toy delay (P = 0.048), and Matrices tasks (P = 0.011), compared with normal control. In terms of the differences among ADHD subtypes, all ADHD presentations had higher scores in several domains of the BRIEF-P (P < 0.001), and the ADHD-combined symptoms (ADHD-C) group had the poorest ratings on inhibition and the ability to Plan/Organize. For neuropsychological measures, the results suggested that the ADHD-C group had poorer performances than the ADHD-predominantly inattentive symptoms (ADHD-I) group on Statue tasks (F = 7.34, η² = 0.12, P < 0.001). Furthermore, the ADHD-hyperactive/impulsive symptoms group had significantly poorer performances compared to the ADHD-C group in the Block Construction task (F = 4.89, η² = 0.067, P = 0.003). However, no significant group differences were found between the ADHD-I group and normal control.

Conclusion:

Based on the combined evaluation of performance-based neuropsychological tests and the BRIEF-P, preschoolers with ADHD show difficulties of neuropsychological function in many aspects.

Effects of a working memory training program in preschoolers with symptoms of attention-deficit/hyperactivity disorder

INTRODUCTION

Preschoolers with attention-deficit/hyperactivity disorder (ADHD) have been found to exhibit impairments on neuropsychological measures of working memory (WM). As WM is an important predictor of future learning abilities, early intervention could help to prevent severe problems. The purpose of this research was to ascertain the efficacy of an intervention for training WM in 5-year-old children with symptoms of ADHD.

METHOD

Thirty-four children with symptoms of ADHD were randomly divided into two groups: One was assigned to the WM training condition, and the other continued normal class activities. The training was provided at school in small groups that also included typically developing children.

RESULTS

The trained group showed a significant improvement in tasks measuring their WM and other controlled processes at conclusion of study, whereas no significant improvement was found in the control group.

CONCLUSIONS

We concluded that early intervention on WM may be effective in children with symptoms of ADHD.

Effect of training focused on executive functions (attention, inhibition, and working memory) in preschoolers exhibiting ADHD symptoms

The development of early intervention strategies for children with symptoms of Attention Deficit Hyperactivity Disorder (ADHD) is important because it provides an opportunity to prevent severe problems in the future. The main purpose of this investigation was to determine the efficacy of a group training for the control of attention, working memory and impulsive behaviors, involving 5-year-old children with ADHD symptoms. Twenty-six children with ADHD symptoms and 26 with typical development were randomly divided in two conditions. Thirteen children in each group were assigned to the training condition and the other to the business as usual condition (normal class activity). Children who participated in the intervention showed an improvement in the tasks measuring their control of attention, impulsive behavior, and working memory. Moreover, children with typical development who attended the training also improved their competencies. The results confirm the importance of an early intervention for preschool-age children with ADHD symptoms.

Executive functioning in children and adolescents with symptoms of sluggish cognitive tempo and ADHD

OBJECTIVE

The aim of this study was to observe whether the independent presence of Sluggish Cognitive Tempo (SCT) directly impacts on the Executive Function (EF), and to determine whether there are deficits in EF that are unique to ADHD predominantly inattentive (ADHD-I) or SCT.

METHOD

Seventy-six participants aged 6 to 17 years and their parents were assessed using a diagnostic interview, an instrument that assesses the EF, and another instrument that assesses the SCT. Two hierarchical linear regression models were performed. The first one analyzed the independent relationship between SCT and EF, and the second model added the symptomatology of ADHD-I.

RESULTS

The SCT has a statistically significant direct relation on the EF deficits and remains in the second model even with the inclusion of the ADHD-I.

CONCLUSION

The SCT and ADHD-I symptoms independently promote executive deficits. Children with ADHD-I symptoms showed deficits in most areas of the EF. Deficits in inhibition and initiative are unique to inattention.

Executive functions in girls with ADHD followed prospectively into young adulthood

OBJECTIVE

We prospectively followed an ethnically and socioeconomically diverse sample of girls with ADHD (n = 140) and a matched comparison group (n = 88) into young adulthood (Mage = 19.6), 10 years after childhood initial assessments, to evaluate neuropsychological functioning. We hypothesized that neuropsychological deficits would persist through young adulthood for those with ADHD, and that those with continuing ADHD symptomatology in young adulthood would show the largest impairments.

METHOD

Neuropsychological measures at follow-up emphasized executive functions (EF) including planning, organization, inhibitory control, sustained attention, working memory, and set shifting.

RESULTS

Parallel to findings from childhood and adolescence, the girls with childhood-diagnosed ADHD displayed medium to large deficits in EF relative to comparisons at follow-up, even with statistical control of baseline demographic and comorbidity variables. The addition of IQ as a covariate attenuated differences but several remained significant. Comparisons between the inattentive and combined subtypes of ADHD yielded nonsignificant results with small effect sizes. EF impairments were evident in both participants whose ADHD diagnoses persisted and in those whose ADHD symptoms had remitted to a nondiagnosable level; both subgroups had more EF deficits than those who did not meet criteria for ADHD in either childhood or young adulthood.

CONCLUSIONS

Those in both the persistent and remitted ADHD groups showed impairments in EF relative to comparisons and generally did not differ from each other. Overall, childhood ADHD in girls portends neuropsychological/EF deficits that persist for at least 10 years.

Excessive discounting of delayed reinforcers as a trans-disease process contributing to addiction and other disease-related vulnerabilities: emerging evidence

Delay discounting describes the devaluation of a reinforcer as a function of the delay until its receipt. Although all people discount delayed reinforcers, one consistent finding is that substance-dependent individuals tend to discount delayed reinforcers more rapidly than do healthy controls. Moreover, these higher-than-normal discounting rates have been observed in individuals with other behavioral maladies such as pathological gambling, poor health behavior, and overeating. This suggests that high rates of delay discounting may be a trans-disease process (i.e., a process that occurs across a range of disorders, making findings from one disorder relevant to other disorders). In this paper, we argue that delay discounting is a trans-disease process, undergirded by an imbalance between two competing neurobehavioral decision systems. Implications for our understanding of, and treatment for, this trans-disease process are discussed.