Parsing ADHD with Temperament Traits

Momentary Dynamics Implicate Emotional Features in the ADHD Phenotype

Emotional dysregulation is increasingly recognized as important to the attention-deficit/hyperactivity disorder (ADHD) phenotype alongside inattention and hyperactivity-impulsivity. Studies of ADHD have relied primarily on trait-based conceptualizations that emphasize stability of symptoms across moderate developmental timescales (i.e., months to years). Trait-based conceptualizations provide a critical view but fail to account for short-term dynamic variations in the expression of ADHD symptoms and emotion. This leaves a gap in our understanding of the short-term variation in ADHD symptom expression and the dynamic relationships among ADHD symptoms and emotion. Here, we assessed caregiver report of ADHD symptoms and positive and negative emotion using ecological momentary approaches over 2 weeks in a sample of 36 children with and without ADHD between the ages of 7-12 years old. Between-person (RKF) and within-person (RC) reliability were estimated. Multilevel models tested specific covariation hypotheses between ADHD symptoms and emotion. Analyses confirmed that ADHD and emotion ratings were reliable as individual differences (i.e., between-person; RKF range 0.93-1.0) and moment-to-moment change (i.e., within-person; Rc range 0.66-0.88) measures. Multilevel models found little evidence for lagged effects between domains, but consistently identified concurrent expression of ADHD symptoms and emotions; inattention covaried most strongly with negative emotion and hyperactivity-impulsivity covaried most strongly with positive emotion. Results demonstrate the importance of complementing trait-level conceptualizations with assessment of momentary dynamics. Momentary assessment suggests important covariation of ADHD symptoms and emotion as part of the ADHD phenotype.

Personality Traits in Relation to Cognitive Disengagement Syndrome and ADHD Inattention in Two Samples of Children

OBJECTIVE

Cognitive disengagement syndrome (CDS; previously referred to as sluggish cognitive tempo) is a set of behaviors, including excessive mind-wandering, mental fogginess, and hypoactivity, that are separate from ADHD inattentive (ADHD-IN) symptoms and linked to functional outcomes. However, CDS and ADHD-IN symptoms are strongly associated, and our understanding of whether personality correlates are similarly or differentially linked to CDS and ADHD-IN is limited. The objective of the current study was to examine personality correlates of CDS and ADHD-IN symptoms across two independent samples of school-aged youth.

METHOD

Study 1 included 207 school-aged children (ages 7-11; 63% male; 87.9% White) with or without teacher-reported elevations in CDS. Study 2 included 263 school-aged children (ages 8-12; 58% male; 75.3% White) with the full range of CDS symptomatology. Parents and teachers completed ratings of ADHD-IN and CDS, and parents also reported on their child's personality dimensions.

RESULTS

Across two samples and controlling for demographic characteristics as well as ADHD-IN symptoms and other personality traits, higher levels of FFFS-fear/shyness were uniquely associated with higher levels of parent- and teacher-reported CDS symptoms. In most models, lower levels of BAS-drive were also uniquely associated with higher levels of CDS. In contrast, when controlling for demographic characteristics and CDS symptoms, higher levels of BAS-impulsivity/fun-seeking were uniquely associated with higher levels of parent- and teacher-reported ADHD-IN symptoms.

DISCUSSION

The findings provide the clearest evidence to date that personality dimensions are differentially associated with ADHD-IN and CDS symptoms in children, further underscoring CDS as a distinct construct from ADHD-IN.

Irritability as a Transdiagnostic Risk Factor for Functional Impairment in Autistic and Non-autistic Toddlers and Preschoolers

Trait irritability in toddlerhood is a powerful risk factor for later internalizing and externalizing challenges in non-autistic children, but the predictive clinical utility of irritability is unknown in autism. Irritability is a trait-level emotional response (i.e., frustration) to a blocked goal and is one source of disruptive behavior. Irritability has two facets: Frustration is the degree to which emotion is elevated after a blocked goal, while soothability is the rate of recovery from peak distress. We aimed to: (1) compare and describe the two facets of irritability in non-autistic and young autistic children, and (2) assess whether children's reward sensitivity and executive function moderate the relation between irritability and clinical symptoms. Participants were 90 autistic (n=43) and non-autistic (n = 47) 2- and 4-year-olds. Autistic children did not have different levels of frustration but were more difficult to soothe compared to non-autistic children, according to parents. Further, frustration and soothability were less strongly correlated for autistic compared to non-autistic children. For all children, executive function (specifically, inhibition) moderated, or ameliorated the strength of, the relation between irritability (both soothability and frustration) and externalizing challenges. This study provides evidence for irritability as a transdiagnostic risk factor for clinically significant emotion regulation challenges. Further, the effect of trait irritability may be ameliorated by children's executive function in a transdiagnostic manner. Future work should examine the unique aspects of soothability to how irritability presents within autism, as well as evaluate and modify emotion regulation interventions for autistic toddlers and preschoolers.

Using Hot and Cool Measures to Phenotype and Predict Functional Outcomes Across Dimensions of ADHD and Typical Development in Adolescents

Multiple pathway models propose that attention deficit hyperactivity disorder (ADHD) arises from dysfunction in separate systems comprised of a "cool" or cognitive pathway versus a "hot" or emotional/reward pathway. Interactions between these pathways and the degree of maturation may further determine functional outcomes for adolescents ranging from those diagnosed with ADHD to typical development (TD). We used a latent profile analysis on rating scales and behavioral task performance assessing emotion, irritability, impulsivity, risk-taking, future orientation, and processing speed (PS) to identify subgroups of TD adolescents and adolescents with ADHD (N = 152) based on the hot and cool pathway model. We identified four classes: 1) High-Complex Challenges; 2) Moderate-Mixed Challenges; 3) Non-Emotive Impulsivity; and 4) High Regulation and Control. A multiple pathway model of ADHD is supported with classes differing in degree of emotional lability and irritability, types of impulsivity, and ability to use future consequences to modulate impulsivity and PS. The classes differed regarding functional behavior, with the High-Complex class demonstrating the most severe functional challenges in academic-related functioning. The Moderate-Mixed class also displayed significant functional challenges but with moderate emotional lability and irritability ratings. The Non-Emotive Impulsivity class exhibited low emotionality and low irritability, yet high impulsivity with limited negative functional consequences, and was composed of a mix of ADHD and TD adolescents. Differences between classes suggest ADHD symptomatology may represent both categorical and dimensional differences. Precision health interventions may be more effective in addressing the specific challenges associated with the classes rather than a one-size-fits-all approach to treating ADHD.

Distal-to-proximal etiologically relevant variables associated with the general (p) and specific factors of psychopathology

BACKGROUND

The general factor of psychopathology, often denoted as p, captures the common variance among a broad range of psychiatric symptoms. Specific factors are co-modeled based on subsets of closely related symptoms. This paper investigated the extent to which wide-ranging genetic, personal, and environmental etiologically relevant variables are associated with p and specific psychopathology factors.

METHODS

Using data from four waves (ages 11-19) of TRAILS, we modeled a bifactor model of p and four specific factors [internalizing, externalizing, ADHD, Autism Spectrum Disorder (ASD)]. Next, we examined the associations of 19 etiologically relevant variables with these psychology factors using path models that organized the variables according to the distal-to-proximal risk principle.

RESULTS

Collectively, the etiologically relevant factors, including temperament traits, accounted for 55% of p's variance, 46% in ADHD, 35% in externalizing, 19% in internalizing, and 7% in ASD. The low 7% is due to insufficient unique variance in ASD indicators that load more strongly on p. Excluding temperament, variables accounted for 29% variance in p, 9% ADHD, 14% EXT, 7% INT, and 4% ASD. Most etiologically relevant factors were generic, predicting p. In addition, we identified effects on specific factors in addition to effects on p (e.g., parental SES, executive functioning); only effects on specific factors (e.g., parental rejection); opposite effects on different factors [e.g., diurnal cortisol (high INT but low EXT, p); developmental delay (high ASD and p but low EXT)]. Frustration, family functioning, parental psychopathology, executive functioning, and fearfulness had strong effects on p.

CONCLUSIONS

(1) Strong generic effects on p suggest that etiologically relevant factors and psychopathology tend to cluster in persons. (2) While many factors predict p, additional as well as opposite effects on specific factors indicate the relevance of specific psychopathology factors in understanding mental disorder. (3) High frustration, neurodevelopmental problems, and a disadvantaged family environment primarily characterize p.

Using Dispositions to Understand Otherwise Intractable Causal Pathways to Psychological Problems During Childhood and Adolescence

Studies of the genetic and environmental factors that make children more or less likely to develop distressing and impairing psychological problems, and studies of the psychobiological pathways through which these causal factors operate, have the goal of improving our understanding of the basic nature of psychological problems to develop better methods of prevention and treatment. For this reason, we have long had our eye on the prize of discovering the causes and psychobiological mechanisms underlying each dimension of psychological problems. There are compelling reasons, however, to seek a different and more achievable prize to understand psychological problems. Dimensions of psychological problems are both far too heterogeneous and too highly correlated to line up with distinct causal pathways. In contrast, a small number of orthogonal cognitive and socioemotional dispositional dimensions are correlated with psychological problems in revealing cross-cutting patterns. Each of these dispositions shares its independent causal pathways with psychological problems and help us understand the complex shared and heterogeneous nature of their causal processes. I outline a strategy for understanding the causes and mechanisms of psychological problems using studies of independently measured dispositions.