The Disruptive Behavior Disorders Rating Scale: Updated Factor Structure, Measurement Invariance, and National Caregiver Norms.

OBJECTIVE: To provide the first caregiver-report national norms for the Disruptive Behavior Disorders Rating Scale (DBDRS) and an updated evaluation of its factor structure and measurement invariance across child sex, informant sex, and child age. METHODS: Caregivers of children aged 5-12 years (N = 962) based in the United States completed the four DBDRS subscales. Using both severity scoring and dichotomous scoring procedures, confirmatory factor analyses supported a four-factor model of inattentive and hyperactive/impulsive symptoms, oppositional defiant symptoms, and conduct disorder symptoms. RESULTS: Measurement invariance was supported, indicating that the DBDRS functions similarly across demographic characteristics. Boys were reported to have more severe symptoms than girls (Cohen's d = 0.33 [inattention], 0.30 [hyperactivity/impulsivity], 0.18 [oppositional defiant disorder], 0.14 [conduct disorder]), female caregivers rated ADHD symptoms as more severe than male caregivers (ds = 0.15 and 0.19 for inattention and hyperactivity/impulsivity, respectively), and older children were reported to experience more inattention than younger children (d = 0.18). Overall, group differences were modest in magnitude. CONCLUSION: This psychometric study supports the continued use of the DBDRS in school-aged youth and will enhance the measure's clinical and research utility by providing the first caregiver-report norms.

A critical review of hot executive functioning in youth attention-deficit/hyperactivity disorder: Methodological limitations, conceptual considerations, and future directions.

Hot executive functioning (EF) - EF under emotionally or motivationally salient conditions - is a putative etiology of attention-deficit/hyperactivity disorder (ADHD), disruptive behavior problems (DBPs), and their related impairments. Despite two decades of research, the present study is the first review of the construct in youth ADHD, with a particular focus on the role of task design, age, and DBPs, as well as relevant conceptual and methodological considerations. While certain hot EF tasks have been investigated extensively (e.g., choice impulsivity), substantial inconsistency in measurement of the broader construct remains, severely limiting conclusions. Future research should a) consider the extent to which various hot EF tasks relate to one another, a higher order factor, and other related constructs; b) further investigate task design, particularly the elicitation of emotion or motivation and its anticipated effect on EF; and c) incorporate multiple levels of analysis to validate similarities and differences among tasks with regard to the affective experiences and cognitive demands they elicit. With improved measurement and conceptual clarity, hot EF has potential to advance the literature on etiological pathways to ADHD, DBPs and associated impairments and, more broadly, may represent a useful tool for understanding the influence of emotion and motivation on cognition.

The impact of ADHD symptom severity on reinforcement and punishment learning among adults.

Introduction: Aberrations in feedback learning are hypothesised to contribute to the behavioural disruptions and impairment of attention-deficit/hyperactivity disorder (ADHD). However, few studies have evaluated the relation of reward/punishment feedback and ADHD symptom severity on learning. The current study evaluates the differential effects of reward and punishment feedback on learning among adults with elevated ADHD. Methods: One hundred five participants self-reported their level of current ADHD symptoms and completed an innovative instrumental learning task. Results: Consistent with predictions, participants with low self-reported ADHD symptom severity benefitted equally from reward and punishment feedback during the learning task, whereas participants with high self-reported symptom severity performed better (indexed by accuracy on learning task) from reward than punishment feedback trials. Conclusions: Overall, adults with high self-reported symptom severity of ADHD learned more from reward-based feedback, which provides critical implications for motivational theories about ADHD, as well as for treatment protocols. Future work should examine the translatability of results within a treatment setting.

Computational modeling reveals strategic and developmental differences in the behavioral impact of reward across adolescence.

Studies of reward effects on behavior in adolescence typically rely on performance metrics that confound myriad cognitive and non-cognitive processes, making it challenging to determine which process is impacted by reward. The present longitudinal study applied the diffusion decision model to a reward task to isolate the influence of reward on response caution from influences of processing and motor speed. Participants completed three annual assessments from early to middle adolescence (N = 387, 55% female, Mage  = 12.1 at Wave 1; Mage  = 13.1 at Wave 2, Mage  = 14.1 at Wave 3) and three annual assessments in late adolescence (Mages  = 17.8, 18.9, 19.9). At each assessment, participants completed a two-choice reaction time task under conditions of no-reward and a block in which points were awarded for speeded accuracy. Reward reduced response caution at all waves, as expected, but had a greater impact as teens moved from early to middle adolescence. Simulations to identify optimal response caution showed that teens were overly cautious in early adolescence but became too focused on speed over accuracy by middle adolescence. By late adolescence, participants adopted response styles that maximized reward. Further, response style was associated with both internalizing and externalizing symptoms in early-to-middle adolescence, providing evidence for the construct validity of a diffusion model approach in this developmental period.

The development of inhibitory control in adolescence and prospective relations with delinquency.

INTRODUCTION: Despite the central role of inhibitory control in models of adolescent development, few studies have examined the longitudinal development of inhibitory control within adolescence and its prospective association with maladaptive outcomes. The current study evaluated: 1) growth in inhibitory control from early- to middle-adolescence, and 2) the relation between inhibitory control and later delinquency. METHODS: Participants included 387 parent-child dyads (11-13 years old at Wave 1; 55% female; USA). Across three annual assessments, teens completed the Stop Signal Task (SST), and parents completed the Inhibitory Control subscale of the Early Adolescent Temperament Questionnaire-Revised. Teens self-reported their delinquent behaviors in early (Mage = 12.1) and middle adolescence (Mage = 14.1) and emerging adulthood (Mage = 18.2). RESULTS: Latent growth curve models indicated that SST performance improved curvilinearly from early to middle adolescence (ages 11-15), with growth slowing around middle adolescence. However, no growth in parent-reported inhibitory control was observed. Lower task-based and parent-reported inhibitory control in early adolescence predicted greater increases in delinquency from middle adolescence to emerging adulthood. However, rate of growth in task-based inhibitory control was unrelated to later delinquency. CONCLUSIONS: This longitudinal study provides a novel examination of the development of inhibitory control across early and middle adolescence. Results suggest that the degree to which inhibitory control confers risk for later delinquency may be captured in early adolescence, consistent with neurodevelopmental accounts of delinquency risk. Differences across assessment tools also highlight the need for careful measurement considerations in future work, as task-based measures may be better suited to capture within-person changes over time.

How do stimulant treatments for ADHD work? Evidence for mediation by improved cognition.

BACKGROUND: Stimulant medications such as methylphenidate (MPH) are the frontline treatment for Attention-Deficit/Hyperactivity Disorder (ADHD). Despite their well-documented efficacy, the mechanisms by which stimulants improve clinical outcomes are not clear. The current study evaluated whether MPH effects on classroom behavior were mediated by improved cognitive functioning. METHODS: Children with ADHD (n = 82; 9-12 years old) participated in a week-long summer research camp, consisting of cognitive testing, classroom periods, and recreational activities. After a baseline day, participants completed a 3-day randomized, double-blind, placebo-controlled trial of MPH (at doses approximating 0.3 and 0.6 mg/kg of immediate-release MPH dosed TID). Cognitive domains included inhibitory control (Stop Signal Task and prepulse inhibition of startle), attention (Continuous Performance Task and reaction time variability), and working memory (forward and backward spatial span). Clinical outcomes included math seatwork productivity and teacher-rated classroom behavior. A within-subjects path-analytic approach was used to test mediation. MPH-placebo and dose-response contrasts were used to evaluate drug effects. RESULTS: Methylphenidate improved seatwork productivity and teacher ratings (ds = 1.4 and 1.1) and all domains of cognition (ds = 0.3-1.1). Inhibitory control (Stop Signal Task, SST) and working memory backward uniquely mediated the effect of MPH (vs. placebo) on productivity. Only working memory backward mediated the impact of MPH on teacher-rated behavior. The dose-response (0.6 vs. 0.3 mg/kg) effects were more modest for clinical outcomes (ds = 0.4 and 0.2) and cognition (ds = 0-0.3); there was no evidence of cognitive mediation of the clinical dose-response effects. CONCLUSIONS: These findings are novel in demonstrating that specific cognitive processes mediate clinical improvement with stimulant treatment for ADHD. They converge with work on ADHD theory, neurobiology, and treatment development in suggesting that inhibitory control and working memory may be mechanisms of stimulant treatment response in ADHD. More work is necessary to evaluate the degree to which these findings generalize to chronic treatment, a broader array of clinical outcomes, and nonstimulant treatments.

Evaluating cognitive and motivational accounts of greater reinforcement effects among children with attention-deficit/hyperactivity disorder.

BACKGROUND: Attention Deficit/Hyperactivity Disorder is associated with cognitive deficits and dysregulated motivation. Reinforcement improves cognitive performance, often to a greater degree among children with ADHD compared to typically-developing controls. The current study tests the degree to which cognitive (individual differences in baseline cognition) and/or motivational (individual differences in Sensitivity to Reward; SR) processes can account for diagnostic group differences in reinforcement effects. METHODS: Participants were 58 children (25 ADHD, 33 control) ages 9-12. Children completed measures of inhibitory control (Stop Signal Task), working memory (n-back), and sustained attention (Continuous Performance Task) during a baseline week and again one week later under reinforcement and no-reinforcement conditions; composites were computed across cognitive domains. Parent-and child-reported trait SR (SPSRQ; BIS/BAS) were combined to index a child's response towards appetitive, rewarding stimuli. RESULTS: In separate analyses, diagnostic group, individual differences in baseline cognition, and individual differences in SR all moderated the impact of reinforcement on cognition. When considered together, the Diagnostic Group × Reinforcement and Baseline Cognition × Reinforcement interactions both remained robust. In contrast, neither the Diagnostic Group × Reinforcement nor the SR × Reinforcement interactions accounted for unique variance when evaluated together. CONCLUSIONS: Both baseline cognition and trait SR predict reinforcement effects on cognition, but only SR shares significant variance with diagnostic group. These results suggest that ADHD children's greater response to reinforcement on cognition is strongly related to their heightened trait sensitivity to rewarding stimuli, consistent with motivational models of ADHD.

Inhibitory Control, Conduct Problems, and Callous Unemotional Traits in Children with ADHD and Typically Developing Children.

Compared children with CP/ADHD, CPCU/ADHD, ADHD-only, and controls on two measures of inhibitory control: a Simon/flanker task that measured response selection and a stop signal task that measured response inhibition. Results showed: (a) ADHD was associated with both measures of inhibitory control; (b) control children had better overall performance and ADHD-only had worse response selection than the CP groups; and (c) children with CPCU/ADHD had better response inhibition than children with ADHD-only or CP/ADHD. Results suggest inhibitory control dysfunction is associated with ADHD rather than CP and that response inhibition dysfunction distinguishes children with CP/ADHD from children with CPCU/ADHD.

Baseline performance moderates stimulant effects on cognition in youth with ADHD.

Attention-deficit/hyperactivity disorder is associated with impaired cognitive functioning and increased delay discounting (i.e., a stronger preference for immediate reward). At the group level, stimulant medication improves cognition and delay discounting, yet not all children exhibit problems in these domains, and previous work has not examined whether stimulant-induced improvements are moderated by baseline performance. To address this question in the current study, 82 children with attention-deficit/hyperactivity disorder (9-12 years old) attended a week-long research camp. On the baseline day (Monday), participants completed tasks of inhibitory control, visuospatial working memory, reaction time variability, and delay discounting. Children then completed a 3-day, randomized, double-blind, placebo-controlled trial of ∼1 mg/kg and 2 mg/kg long-acting methylphenidate (mean doses = 39.1 and 74.3 mg, respectively), during which they were readministered the battery of tasks. Cognitive composites (mean of inhibitory control, working memory, and reaction time variability performance) were created for the baseline and medication evaluation phases. As predicted, the extent to which cognition was improved with medication compared with placebo and with 2 mg/kg compared with 1 mg/kg was greatest among children with poorer baseline cognitive function. Children with stronger baseline cognition exhibited less improvement with methylphenidate compared with placebo and did not benefit from the 2 compared with the 1 mg/kg dose. In contrast, medication-related improvement in delay discounting was unrelated to baseline discounting. Given that improving cognitive function is one potential mechanisms by which stimulants exert their therapeutic effects, this study has significant implications for understanding how and for whom stimulant medication works. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Brief report: Evaluation of working memory deficits in children with ADHD using the NIH list sorting working memory task.

Variability in working memory (WM) task selection likely contributes to heterogeneity in effect size estimates of deficiencies in youth with attention-deficit/hyperactivity disorder (ADHD). This has resulted in the development of brief, easy to administer assessments such as the NIH List Sorting Working Memory (LSWM) task from the NIH Cognitive Toolbox in hopes of standardizing measurement of this construct. Unfortunately, substantial questions persist regarding the specific constructs being evaluated by this task (e.g., visuospatial [VS] or phonological [PH] WM) as well as the ability of this task to detect WM deficits in previously identified impaired groups (e.g., ADHD). The current study examines the extent to which the LSWM task is associated with VS and PHWM performance as well as symptoms of ADHD. Additionally, we examined the magnitude of differences between ADHD and Typically Developing (TD) youth on this task relative to empirically derived WM tasks utilized in the past. Forty-six children (25 ADHD, 21 TD) completed multiple WM tasks. The LSWM task was moderately associated with PHWM and demonstrated relatively weaker associations with VSWM. Symptoms of inattention and hyperactivity/impulsivity were unrelated to the LSWM task; whereas tasks assessing PH and VSWM were moderately associated with inattention and weakly associated with hyperactivity (VSWM only). No significant between-group differences in performance emerged on the LSWM task; however, significant large-magnitude group differences were observed on both the PH and VSWM tasks. These findings suggest that the LSWM task may lack the ability to detect WM difficulties in youth with ADHD.