Mark D. Rapport

Attention‐Deficit/Hyperactivity Disorder and Scholastic Achievement: A Model of Dual Developmental Pathways

A conceptual model has recently been hypothesized in which parallel but correlated developmental pathways exist for attention deficit behaviors and conduct problems. An important component of this model suggests that attention deficit behaviors are related to later scholastic underachievement, whereas conduct problems are unrelated to scholastic underachievement except by their common correlation with attention deficit and intelligence. The present study replicated the general model using a cross-sectional sample of 325 children, and examined whether hypothesized dual pathways (behavioral and cognitive) better account for the relationship between attention deficit, intelligence, and later scholastic achievement. Results of the structural equation modeling analysis were consistent with the hypothesized dual pathway model and suggest that school behavior and select cognitive abilities serve as important mediators between attention deficit, intelligence, and later scholastic achievement. Implications of these results for understanding the developmental trajectory of children with attention deficit and general theoretical models of ADHD are discussed.

Attention Deficit Disorder and Methylphenidate: Normalization Rates, Clinical Effectiveness, and Response Prediction in 76 Children

OBJECTIVE To evaluate the magnitude and clinical significance of methylphenidate (MPH) effects on the classroom behavior and academic performance of 76 children with attention deficit disorder/hyperactivity (ADDH). METHOD A double-blind, placebo controlled, within-subject (crossover) experimental design was used to evaluate acute MPH effects at four dose levels (5 mg, 10 mg, 15 mg, and 20 mg) on childrens attention, academic functioning, and behavior in regular classroom settings. Results were contrasted with a normal control sample. RESULTS Standard statistical analysis revealed MPH effects on classroom functioning that were primarily linear. Analysis of the clinical significance of effects indicated that large proportions of treated children exhibited significantly improved or normalized classroom functioning; however, a large subset of them failed to show improved academic functioning. Overall, children failing to respond at lower dose levels have a high probability of improving or becoming normalized as a function of increasing dose. CONCLUSIONS For a majority of children with ADDH, MPH results in significantly improved or normalized attention and classroom behavior. A significant subset, however, fail to realize gains in their academic functioning and will require supplemental interventions.

Working Memory Deficits in Boys with Attention-deficit/ Hyperactivity Disorder (ADHD): The Contribution of Central Executive and Subsystem Processes

The current study investigated contradictory findings from recent experimental and meta-analytic studies concerning working memory deficits in ADHD. Working memory refers to the cognitive ability to temporarily store and mentally manipulate limited amounts of information for use in guiding behavior. Phonological (verbal) and visuospatial (nonverbal) working memory were assessed across four memory load conditions in 23 boys (12 ADHD, 11 typically developing) using tasks based on Baddeley’s (Working memory, thought, and action, Oxford University Press, New York, 2007) working memory model. The model posits separate phonological and visuospatial storage and rehearsal components that are controlled by a single attentional controller (CE: central executive). A latent variable approach was used to partial task performance related to three variables of interest: phonological buffer/rehearsal loop, visuospatial buffer/rehearsal loop, and the CE attentional controller. ADHD-related working memory deficits were apparent across all three cognitive systems—with the largest magnitude of deficits apparent in the CE—even after controlling for reading speed, nonverbal visual encoding, age, IQ, and SES.

Do programs designed to train working memory, other executive functions, and attention benefit children with ADHD? A meta-analytic review of cognitive, academic, and behavioral outcomes

Children with ADHD are characterized frequently as possessing underdeveloped executive functions and sustained attentional abilities, and recent commercial claims suggest that computer-based cognitive training can remediate these impairments and provide significant and lasting improvement in their attention, impulse control, social functioning, academic performance, and complex reasoning skills. The present review critically evaluates these claims through meta-analysis of 25 studies of facilitative intervention training (i.e., cognitive training) for children with ADHD. Random effects models corrected for publication bias and sampling error revealed that studies training short-term memory alone resulted in moderate magnitude improvements in short-term memory (d=0.63), whereas training attention did not significantly improve attention and training mixed executive functions did not significantly improve the targeted executive functions (both nonsignificant: 95% confidence intervals include 0.0). Far transfer effects of cognitive training on academic functioning, blinded ratings of behavior (both nonsignificant), and cognitive tests (d=0.14) were nonsignificant or negligible. Unblinded raters (d=0.48) reported significantly larger benefits relative to blinded raters and objective tests (both p<.05), indicating the likelihood of Hawthorne effects. Critical examination of training targets revealed incongruence with empirical evidence regarding the specific executive functions that are (a) most impaired in ADHD, and (b) functionally related to the behavioral and academic outcomes these training programs are intended to ameliorate. Collectively, meta-analytic results indicate that claims regarding the academic, behavioral, and cognitive benefits associated with extant cognitive training programs are unsupported in ADHD. The methodological limitations of the current evidence base, however, leave open the possibility that cognitive training techniques designed to improve empirically documented executive function deficits may benefit children with ADHD.

A Conceptual Model of Child Psychopathology: Implications for Understanding Attention Deficit Hyperactivity Disorder and Treatment Efficacy

Highlights the desirability of using a theoretical framework for guiding the design and evaluation of therapeutic interventions for children with attention deficit hyperactivity disorder (ADHD). A general conceptual model is introduced and used to evaluate ADHD treatment outcome research. Treatments designed to target the substrate level(pharmacological interventions) result in broad, robust improvement in both core and peripheral areas of functioning. Those targeting hypothesized core features of the disorder (i.e., attention, impulsivity–hyperactivity) produce corresponding improvement in core and peripheral outcome measures with the exception of studies employing cognitive–behavior therapy. Those targeting peripheral features of the disorder effect change only in corresponding peripheral areas of functioning. Implications for clinical practice are discussed, and an alternative conceptual model of ADHD is introduced and compared with existing models.

ADHD and Working Memory: The Impact of Central Executive Deficits and Exceeding Storage/Rehearsal Capacity on Observed Inattentive Behavior

Inattentive behavior is considered a core and pervasive feature of ADHD; however, an alternative model challenges this premise and hypothesizes a functional relationship between working memory deficits and inattentive behavior. The current study investigated whether inattentive behavior in children with ADHD is functionally related to the domain-general central executive and/or subsidiary storage/rehearsal components of working memory. Objective observations of children’s attentive behavior by independent observers were conducted while children with ADHD (n = 15) and typically developing children (n = 14) completed counterbalanced tasks that differentially manipulated central executive, phonological storage/rehearsal, and visuospatial storage/rehearsal demands. Results of latent variable and effect size confidence interval analyses revealed two conditions that completely accounted for the attentive behavior deficits in children with ADHD: (a) placing demands on central executive processing, the effect of which is evident under even low cognitive loads, and (b) exceeding storage/rehearsal capacity, which has similar effects on children with ADHD and typically developing children but occurs at lower cognitive loads for children with ADHD.

Internalizing Behavior Problems and Scholastic Achievement in Children: Cognitive and Behavioral Pathways as Mediators of Outcome

Examined a conceptual model in which dual developmental pathways (behavioral and cognitive) are hypothesized to account for the relation among internalizing behavior problems, intelligence, and later scholastic achievement using a cross-sectional sample of 325 children. Classroom behavior and select aspects of cognitive functioning (vigilance, short-term memory) were hypothesized to mediate the relations among internalizing problems, IQ, and long-term scholastic achievement. Hierarchical tests applied to a nested series of models demonstrated that (a) individual differences in measured intelligence among children are associated with variations in classroom performance and cognitive functioning, (b) classroom performance and cognitive functioning make unique contributions to prediction of later achievement over and above the influence of intelligence, (c) anxious/depressive features are correlated but separable constructs, and (d) anxiety/depression and withdrawal contribute to prediction of classroom performance and cognitive functioning over and above the effects of intelligence. Classroom performance and cognitive functioning thus appear to mediate the effects of internalizing behaviors as well as intelligence. Particular attention to the presence and potential impact of social withdrawal on childrens functioning, both alone and concomitant with anxiety/depression, appears warranted during the course of clinical evaluations owing to the strong continuity among these variables.

Attention deficit/hyperactivity disorder and methylphenidate. A review of height/weight, cardiovascular, and somatic complaint side effects.

Three classes (height/weight, cardiovascular, and somatic complaints) of treatment emergent symptoms (side effects) associated with methylphenidate (MPH) therapy for children with attention deficit/hyperactivity disorder (ADHD) are reviewed. The more easily quantifiable side effects (e.g., blood pressure [BP], heart rate [HR], height/weight) are mostly transient, dose-dependent, easily rectified with dosage adjustments, and considered minor from a clinical perspective considering the breadth and level of improvement in behavior and cognitive functioning observed in most children. Previously reported somatic complaints associated with psychostimulant therapy may reflect symptoms occurring prior to initiation of treatment and require additional study.

Attention Deficit Disorder with Hyperactivity

Attention deficit disorder with hyperactivity (ADDH) is a serious and pervasive psychopathological disorder of childhood characterized by inattention, impulsivity, and excessive gross motor activity (American Psychiatric Association, 1980). Associated features of the disorder frequently include poor peer relationships, learning disabilities, academic failure, conduct disturbance, and aggression.

Working Memory Deficits and Social Problems in Children with ADHD

Social problems are a prevalent feature of ADHD and reflect a major source of functional impairment for these children. The current study examined the impact of working memory deficits on parent- and teacher-reported social problems in a sample of children with ADHD and typically developing boys (N = 39). Bootstrapped, bias-corrected mediation analyses revealed that the impact of working memory deficits on social problems is primarily indirect. That is, impaired social interactions in children with ADHD reflect, to a significant extent, the behavioral outcome of being unable to maintain a focus of attention on information within working memory while simultaneously dividing attention among multiple, on-going events and social cues occurring within the environment. Central executive deficits impacted social problems through both inattentive and impulsive-hyperactive symptoms, whereas the subsidiary phonological and visuospatial storage/rehearsal systems demonstrated a more limited yet distinct relationship with children’s social problems.