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

Functional and structural connectivity of the subregions of the amygdala in ADHD children with or without ODD

OBJECTIVES

The current study aimed to investigate the structural and functional connectivity of the subregions of the amygdala in children with Attention Deficit/Hyperactivity Disorder (ADHD) only or comorbid with Oppositional Defiant Disorder (ODD).

METHODS

A total of 354 children with ADHD-only, 161 children with ADHD and ODD (ADHD + ODD), and 100 healthy controls were enrolled. The Child Behavior Checklist (CBCL) and the Behavior Rating Inventory of Executive Function (BRIEF) were filled out by caregivers. Analysis of covariance (ANCOVA) was performed to test group-wise differences in these behavioral measures. A subsample comprising 209 participants underwent a resting-state functional MRI scan and a diffusion-weighted imaging (DWI) scan. Functional connectivity and structural connectivity were calculated using bilateral subregions of the Amygdala as seeds. Between-group voxel-wise comparisons were conducted.

RESULTS

The ADHD + ODD group had more anxious/depressed moods, more delinquent and aggressive behaviors, more emotional control problems, and more inhibition deficits than the ADHD-only group (all PBonferroni-corrected < 0.05). Compared with the control and ADHD + ODD groups, the ADHD-only group displayed increased FC strength between the amygdala subregions and the left caudate, left putamen, and frontal cortex. Regarding structural connectivity (SC), the ADHD-only group demonstrated higher streamline density in the left internal capsule, corpus callosum, and the right superior corona radiata. The altered SC was associated with emotional problems in children with ADHD, while the altered FC was associated with other ADHD-related clinical features.

CONCLUSIONS

Altered structural and functional connectivity of the subregions of the amygdala in children with ADHD compared with their healthy counterparts were respectively associated with ADHD-related behavioral and emotional problems.

CLINICAL TRIAL NUMBER

not applicable.

Executive function deficits in attention-deficit/hyperactivity disorder and autism spectrum disorder

Executive function deficits have been reported in both autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). However, little is known regarding which, if any, of these impairments are unique vs. shared in children with ADHD versus ASD. In this Review, we provide an overview of the current literature with a critical eye toward diagnostic, measurement, and third-variable considerations that should be leveraged to provide more definitive answers. We conclude that the field's understanding of ASD and ADHD executive function profiles is highly limited because most research on one disorder has failed to account for their co-occurrence and the presence of symptoms of the other disorder; a vast majority of studies have relied on traditional neuropsychological tests and/or informant-rated executive function scales that have poor specificity and construct validity; and most studies have been unable to account for the well-documented between-person heterogeneity within and across disorders. Currently, the most parsimonious conclusion is that children with ADHD and/or ASD tend to perform moderately worse than neurotypical children on a broad range of neuropsychological tests. However, the extent to which these difficulties are unique vs. shared, or attributable to impairments in specific executive functions subcomponents, remains largely unknown. We end with focused recommendations for future research that we believe will advance this important line of inquiry.

Unraveling the spectrum: overlap, distinctions, and nuances of ADHD and ASD in children

This review explores the clinical presentation of similarities and differences in Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD). This paper investigates the deficits in executive function, social function, and emotional intelligence that are seen in both conditions and how the presence of both conditions can exacerbate these deficiencies. Understanding the clinical presentations in these domains is critical to refine diagnostic methods and treatments and improve outcomes for those affected by these neurodevelopmental disorders. The similarities in clinical presentation between ADHD and ASD present a significant diagnostic challenge, with individuals often exhibiting similar behaviors and difficulty navigating the complexities that encompass reacting to their environment. Further research is paramount in gaining more knowledge of the disorders and challenges faced by these individuals, especially those with the presence of both conditions.

Attentional spatial cueing of the stop-signal affects the ability to suppress behavioural responses

The ability to adapt to the environment is linked to the possibility of inhibiting inappropriate behaviours, and this ability can be enhanced by attention. Despite this premise, the scientific literature that assesses how attention can influence inhibition is still limited. This study contributes to this topic by evaluating whether spatial and moving attentional cueing can influence inhibitory control. We employed a task in which subjects viewed a vertical bar on the screen that, from a central position, moved either left or right where two circles were positioned. Subjects were asked to respond by pressing a key when the motion of the bar was interrupted close to the circle (go signal). In about 40% of the trials, following the go signal and after a variable delay, a visual target appeared in either one of the circles, requiring response inhibition (stop signal). In most of the trials the stop signal appeared on the same side as the go signal (valid condition), while in the others, it appeared on the opposite side (invalid condition). We found that spatial and moving cueing facilitates inhibitory control in the valid condition. This facilitation was observed especially for stop signals that appeared within 250ms of the presentation of the go signal, thus suggesting an involvement of exogenous attentional orienting. This work demonstrates that spatial and moving cueing can influence inhibitory control, providing a contribution to the investigation of the relationship between spatial attention and inhibitory control.