Does Anxiety Systematically Bias Estimates of Executive Functioning Deficits in Pediatric Attention-Deficit/Hyperactivity Disorder?

Growing evidence suggests that childhood ADHD is associated with larger impairments in working memory relative to inhibition. However, most studies have not considered the role of co-occurring anxiety on these estimates - a potentially significant confound given prior evidence that anxiety may increase working memory difficulties but decrease inhibition difficulties for these children. The current study extends prior work to examine the extent to which co-occurring anxiety may be systematically affecting recent estimates of the magnitude of working memory/inhibitory control deficits in ADHD. The carefully-phenotyped sample included 197 children with ADHD and 142 children without ADHD between the ages of 8 and 13 years (N = 339; Mage = 10.31, SD = 1.39; 144 female participants). Results demonstrated that ADHD diagnosis predicted small impairments in inhibitory control (d = 0.31) and large impairments in working memory (d = 0.99). However, child trait anxiety assessed dimensionally across multiple informants (child, parent, teacher) did not uniquely predict either executive function, nor did it moderate estimates of ADHD-related working memory/inhibition deficits. When evaluating anxiety categorically and controlling for ADHD, anxiety diagnosis predicted slightly better working memory (d = 0.19) but not inhibitory control for clinically evaluated children generally. Findings from the current study indicate that trait anxiety, measured dimensionally or categorically, does not differentially affect estimates of executive dysfunction in pediatric ADHD. Further, results suggest that trait anxiety is generally not associated with executive dysfunction above and beyond the impact of co-occurring ADHD. Future research is needed to further assess the role of anxiety in ADHD behavioral symptomatology, neurocognitive functioning, and mechanisms underlying these relations.

The relation between executive functions, error-related brain activity, and ADHD symptoms in clinically evaluated school-aged children.

Two event-related potentials (ERPs) elicited following errors, the error-related negativity (ERN) and error positivity (Pe), have been proposed to reflect cognitive control, though the specific processes remain debated. Few studies have examined the ERN and Pe's relations with individual differences in cognitive control/executive functioning using well-validated tests administered separately from the inhibition tasks used to elicit the ERN/Pe. Additionally, neurocognitive tests of executive functions tend to strongly predict ADHD symptoms, but the extent to which task-based and EEG-based estimates of executive functioning/cognitive control account for the same variance in ADHD symptoms remains unclear. The current study addressed these limitations by examining relations between the ERN/Pe and three core executive functions (working memory, inhibitory control, set shifting) in a clinically-evaluated sample of 53 children ages 8-12 (Mage = 10.36, SD = 1.42; 77.4% White/Non-Hispanic; 16 girls) with and without ADHD. Results demonstrated that neither the ERN nor Pe were related to overall cognitive control/executive functioning, or to working memory or set shifting specifically (all 95%CIs include 0.0). In contrast, a larger Pe was associated with better-developed inhibitory control (ß=-.35, 95%CI excludes 0.0), but did not capture aspects of inhibitory control that are important for predicting ADHD symptoms. Neither the ERN nor Pe predicted ADHD symptoms (95%CIs include 0.0). Results were generally robust to control for age, sex, SES, ADHD symptom cluster, and anxiety, and emphasize the need for caution when interpreting the ERN/Pe as indices of broad-based cognitive control/executive functioning, as well as using the ERN/Pe to examine cognitive processes contributing to ADHD symptomatology.

Linking ADHD and ASD Symptomatology with Social Impairment: The Role of Emotion Dysregulation.

Children with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) often experience social impairments. These children also frequently struggle with emotion regulation, and extant literature suggests that emotion dysregulation predicts social impairment in both clinical and neurotypical populations. However, the evidence base linking ADHD/ASD with social impairment comes primarily from samples meeting full diagnostic criteria for ADHD and/or ASD despite evidence that both syndromes reflect extreme ends of natural continuums that are normally distributed across the general population. To our knowledge, the present study is the first to concurrently examine unique and overlapping relations among ADHD/ASD symptoms, emotion regulation, and social difficulties using multi-informant measures (parent, teacher) with a clinically-evaluated sample of 108 children ages 8-13 (40 girls; 66% White/Non-Hispanic) with and without clinically-elevated ASD and ADHD symptoms and other common clinical disorders. Bias-corrected, bootstrapped conditional effects modeling revealed that ADHD-inattentive (ß=-0.23) and ASD-social communication (ß=-0.20) symptoms predicted social impairment directly, whereas ADHD-hyperactive/impulsive (ß=-0.06) and ASD-restricted/repetitive behavior/interests (ß=-0.06) symptoms predicted social impairment only via their shared associations with emotion dysregulation. Sensitivity analyses revealed that most relations were robust to control for item overlap across measures. In contrast, only the ADHD-inattention/social impairment link was robust to control for mono-informant bias, highlighting the importance of multi-informant methods and the potential for different determinants of social functioning across settings. Overall, this study implicates emotion regulation skills and all four ADHD/ASD symptom clusters as potential influences on children's social functioning, albeit with a more nuanced and potentially setting-specific pattern than suggested by prior work.