Executive Functioning Heterogeneity in Pediatric ADHD

Abstract

Neurocognitive heterogeneity is increasingly recognized as a valid phenomenon in ADHD, with most estimates suggesting that executive dysfunction is present in only about 33%-50% of these children. However, recent critiques question the veracity of these estimates because our understanding of executive functioning in ADHD is based, in large part, on data from single tasks developed to detect gross neurological impairment rather than the specific executive processes hypothesized to underlie the ADHD phenotype. The current study is the first to comprehensively assess heterogeneity in all three primary executive functions in ADHD using a criterion battery that includes multiple tests per construct (working memory, inhibitory control, set shifting). Children ages 8-13 (M = 10.37, SD = 1.39) with and without ADHD (N = 136; 64 girls; 62% Caucasian/Non-Hispanic) completed a counterbalanced series of executive function tests. Accounting for task unreliability, results indicated significantly improved sensitivity and specificity relative to prior estimates, with 89% of children with ADHD demonstrating objectively-defined impairment on at least one executive function (62% impaired working memory, 27% impaired inhibitory control, 38% impaired set shifting; 54% impaired on one executive function, 35% impaired on two or all three executive functions). Children with working memory deficits showed higher parent- and teacher-reported ADHD inattentive and hyperactive/impulsive symptoms (BF = 5.23 × 10), and were slightly younger (BF = 11.35) than children without working memory deficits. Children with vs. without set shifting or inhibitory control deficits did not differ on ADHD symptoms, age, gender, IQ, SES, or medication status. Taken together, these findings confirm that ADHD is characterized by neurocognitive heterogeneity, while suggesting that contemporary, cognitively-informed criteria may provide improved precision for identifying a smaller number of neuropsychologically-impaired subtypes than previously described.

Cognitive correlates of ADHD subtypes and its association with self-esteem: A quantitative difference

“…Taken together, our results show that there is subtype-specific cognitive profile in ADHD confirming a cognitive heterogeneity in ADHD in line with recent evidence [41]. ADHD subtype is an important contributing factor not only to cognitive strength/weakness but also self-esteem ratings.…”

“…Previous studies using the Wechsler Intelligence Scale in both children and adults with ADHD, regardless of subtype, showed that working memory and processing speed are usually among the most impaired domains in ADHD patients compared to healthy controls [11,17,25,40]. A recent study that comprehensively examined executive functioning heterogeneity in pediatric ADHD using neuropsychological battery also found a positive association between impaired working memory and exhibiting higher ADHD symptoms [41]. Our results are generally in line with these studies by showing WM as the most impaired domain in all subtypes.…”

Is There a Functional Relation Between Set Shifting and Hyperactivity in Children with Attention-Deficit/Hyperactivity Disorder (ADHD)?

“…The incongruence between our a priori hypothesis and our findings may be because the former was developed from mixed findings across correlational studies rather than from experimentally manipulated cognitive demands and objectively measured behavior. Additionally, these findings coincide with recent evidence, based on part on the current sample, indicating that children with ADHD likely do not have unique set shifting deficits (Irwin et al, 2019), and that set shifting abilities do not covary with ADHD-related hyperactive/impulsive symptom severity (Kofler, Irwin et al, 2019).…”

Predictive Modelling of The Dynamic Patterns of Thinking in Attention-Deficit/Hyperactivity Disorder: Diagnostic Accuracy of Spatiotemporal Fractal Measures

“…This methodology is also convergent with new complementary theoretical views, that shows that EF dynamics could be adequately modelled by spatiotemporal "interaction-dominant" processes (Ihlen and Vereijken, 2010;Anastas et al, 2014). Moreover, the increasing attention to dynamics measures such as reaction time variability in ADHD during EF task, is also an illustrative example of another convergent trends in ADHD research (Kofler et al, 2013(Kofler et al, , 2018 Notwithstanding, an important epistemological caveat must be placed here to avoid misunderstandings, the "ratio cognoscendi " shall not be confused with the "ratio essendi " of the phenomena described and analysed by using multiscaling techniques, including those advocated in this work (Piaget, 2006). It is important to bear in mind what Labra-Spröhnle (2017) and Gigerenzer (2007) described about the complex epistemological dialectic between tools and theories and their explanatory limitations due to their mutual constructive entanglement.…”