Cognitive Deficits and Positively Biased Self-Perceptions in Children with ADHD

This study examined the relation between cognitive deficits and positive bias in a sample of 272 children with and without Attention Deficit Hyperactivity Disorder (ADHD; 7–12 years old). Results indicated that children with ADHD with and without biased self-perceptions exhibit differences in specific cognitive deficits (executive processes, working memory, broad attention, and cognitive fluency) compared to each other and to control children. Further, specific cognitive deficits emerged as partial mediators of the relation between ADHD diagnostic status and positive bias. Interestingly, some differences in results emerged based on the domain considered (academic, social, behavioral competence). Results lend initial support to the role of cognitive deficits in the positive bias of some children with ADHD. Implications for future research and intervention are discussed.     

WISC-IV and WISC-III profiles in children with ADHD

Wechsler Intelligence Scale for Children, 3rd and 4th editions (WISC-III n = 586 and WISC-IV n = 118), profiles were compared for children with ADHD and normal intelligence. Mean Verbal Comprehension Index (VCI) and Perceptual Organization/Perceptual Reasoning Index (POI/PRI) scores were significantly higher than Freedom From Distractibility/Working Memory Index (FDI/WMI) and Processing Speed Index (PSI), and Symbol Search was higher than Coding. FDI/WMI and PSI scores were similar on both tests, but VCI and POI/PRI were higher on the WISC-IV than on the WISC-III. Therefore, index discrepancies were greater for the WISC-IV, suggesting that the WISC-IV might be better than the WISC-III in delineating the strengths and weaknesses of children with ADHD. All children in the WISC-IV sample scored lowest on WMI or PSI, whereas only 88% of the WISC-III children scored lowest on FDI or PSI. Thus, the WISC-IV may be more helpful in diagnosing ADHD than the WISC-III.     

Sluggish Cognitive Tempo Symptoms Contribute to Heterogeneity in Adult Attention-Deficit Hyperactivity Disorder

Attention-deficit hyperactivity disorder (ADHD) persists into adulthood in over 50% of cases, although its associated symptom profiles, comorbid problems, and neuropsychological deficits change substantially across development. Sluggish cognitive tempo (SCT) symptoms may contribute to associations between ADHD and comorbid problems and may partially explain the substantial heterogeneity observed in its correlates. 349 adults aged 18–38 years (M = 23.2, SD = 4.5, 54.7% male, 61.03% with ADHD) completed a multi-informant diagnostic procedure and a comprehensive neuropsychological battery. Adults with ADHD (n = 213) were retained for analyses. Latent class analyses (LCA) revealed three profiles of SCT symptoms among those with ADHD, which we classified as minimal, moderate, or severe SCT. Multiple analysis of covariance (MANCOVA) revealed significant differences among these profiles, which remained when controlling for persistence of ADHD symptoms and sex. In general, adults with ADHD combined with SCT symptoms (moderate and severe) had significantly more symptoms of anxiety, depression, and persistent inattention, and had more severe professional and relational impairment compared to ADHD adults without SCT. Compared to those with moderate or minimal SCT symptoms, the severe SCT group had the most symptoms of depression and internalizing disorders, and the most impairment in the domain of daily responsibility. No significant differences based on externalizing symptoms emerged when controlling for sex and persistence of inattention symptoms, suggesting the moderate and severe SCT groups do not simply reflect more symptoms. Moreover, follow-up mediation analyses revealed that SCT might at least partially explain the heterogeneity in ADHD. Findings have implications for refinement of etiological conceptualization, assessment methods, and intervention strategies.     

Specific Cognitive Deficits in ADHD: A Diagnostic Concern in Differential Diagnosis

We present a critical account of existing tools used to diagnose children with Attention Deficit Hyperactivity Disorder and to make a case for the assessment of cognitive impairments as a part of diagnostic system. Surveys have shown that clinicians rely almost entirely upon subjective reports or their own clinical judgment when arriving at diagnostic decisions relating to this prevalent disorder. While information from parents and teachers should always be carefully considered, they are often influenced by a host of emotional and perceptual factors. It increases the possibility for misdiagnosis of a condition like ADHD. Recent experimental literature on ADHD has identified unique underlying cognitive dysfunction, specific to ADHD. Therefore, we propose that there is a need to incorporate information on cognitive mechanisms underlying ADHD and inculcate such information in the diagnostic system, which will provide a more sensitive as well as specific tool in differential diagnosis of ADHD.     

The Gordon Diagnostic System and WISC-III Freedom from Distractibility Index: validity in identifying clinic-referred children with and without ADHD

Gordon Diagnostic System and WISC-III scores for clinic-referred 6- to 16-yr.-olds (184 with ADHD Combined Type and 46 without ADHD) were analyzed to evaluate the combination of scores and cutpoints that maximized diagnostic accuracy. Using an "ADHD cutpoint" of IQ minus the GDS Composite score > or = 13, 87.8% of the children were correctly identified as having or not having ADHD. IQ minus Freedom from Distractibility > 0 yielded 73.5% accuracy. When the two meaures were combined to create new criteria (IQ minus GDS Composite > or = 13 or IQ minus Freedom from Distractibility > or = 11), diagnostic accuracy increased to 90.9% and negative predictive power improved substantially. Diagnostic agreement between the Gordon Diagnostic System and Freedom from Distractibility was 70%, suggesting that the two tests measure both similar and unique traits.     

An exploration into the creative abilities of children with ADHD

The purpose of this study is to explore whether ADHD is associated with high creative ability. Sixty-seven children, ages 10 to 12 (33 ADHD and 34 controls) completed the Torrance Tests of Creative Thinking (TTCT), Maier's Two-String Problem, and the Block Design and Vocabulary subsets of the Wechsler Intelligence Scale for Children (WISC-III). The results show that there is no significant difference between the ADHD group's and control group's performance on either the TTCT, Maier's Two-String Problem, or WISC-III, suggesting that children diagnosed with ADHD are no more creative than children without the diagnosis.     

A trial-by-trial analysis reveals more intense physical activity is associated with better cognitive control performance in attention-deficit/hyperactivity disorder

Hyperactivity is a key symptom and the most observable manifestation of attention-deficit/hyperactivity disorder (ADHD). The over-activity associated with ADHD can cause specific challenges in academic settings, extracurricular activities and social relationships. Cognitive control challenges are also well established in ADHD. The current study included 44 children between the ages of 10 and 17 diagnosed with ADHD or who were typically developing (TD), all of whom had no psychiatric co-morbidity or significant learning disorders. Participants wore an actometer on their ankle while performing a flanker paradigm in order to objectively measure their rates of activity in association with cognitive control. Analyses assessed the relationship between frequency and intensity of activity to task accuracy on a trial-by-trial basis. A significant interaction effect between group and performance revealed that more intense movement was associated with better performance in the ADHD group but not in the TD group. The ADHD group demonstrated more intense activity than the TD group during correct (but not error) trials. Within-group, children with ADHD generated higher intensity movements in their correct trials compared to their error trials, whereas the TD group did not demonstrate any within-group differences. These findings suggest that excessive motoric activity associated with clinically significant ADHD symptoms may reflect compensatory efforts to modulate attention and alertness. Future research should systematically explore the relationship between motion in ADHD and how it might be used to improve cognitive performance.     

Overlapping and Distinct Cognitive Impairments in Attention-Deficit/Hyperactivity and Autism Spectrum Disorder without Intellectual Disability

Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are commonly comorbid, share genetic liability, and often exhibit overlapping cognitive impairments. Clarification of shared and distinct cognitive effects while considering comorbid symptoms across disorders has been lacking. In the current study, children ages 7–15 years assigned to three diagnostic groups:ADHD (n?=?509), ASD (n?=?97), and controls (n?=?301) completed measures spanning the cognitive domains of attention/arousal, working memory, set-shifting, inhibition, and response variability. Specific processes contributing to response variability were examined using a drift diffusion model, which separately quantified drift rate (i.e., efficiency of information processing), boundary separation (i.e., speed-accuracy trade-offs), and non-decision time. Children with ADHD and ASD were impaired on attention/arousal, processing speed, working memory, and response inhibition, but did not differ from controls on measures of delayed reward discounting, set-shifting, or interference control. Overall, impairments in the ASD group were not attributable to ADHD symptoms using either continuous symptom measures or latent categorical grouping approaches. Similarly, impairments in the ADHD group were not attributable to ASD symptoms. When specific RT parameters were considered, children with ADHD and ASD shared impairments in drift rate. However, children with ASD were uniquely characterized by a wider boundary separation. Findings suggest a combination of overlapping and unique patterns of cognitive impairment for children with ASD as compared to those with ADHD, particularly when the processes underlying reaction time measures are considered separately.     

Cognitive Load Differentially Impacts Response Control in Girls and Boys with ADHD

Children with attention-deficit hyperactivity disorder (ADHD) consistently show impaired response control, including deficits in response inhibition and increased intrasubject variability (ISV) compared to typically-developing (TD) children. However, significantly less research has examined factors that may influence response control in individuals with ADHD, such as task or participant characteristics. The current study extends the literature by examining the impact of increasing cognitive demands on response control in a large sample of 81children with ADHD (40 girls) and 100 TD children (47 girls), ages 8–12 years. Participants completed a simple Go/No-Go (GNG) task with minimal cognitive demands, and a complex GNG task with increased cognitive load. Results showed that increasing cognitive load differentially impacted response control (commission error rate and tau, an ex-Gaussian measure of ISV) for girls, but not boys, with ADHD compared to same-sex TD children. Specifically, a sexually dimorphic pattern emerged such that boys with ADHD demonstrated higher commission error rate and tau on both the simple and complex GNG tasks as compared to TD boys, whereas girls with ADHD did not differ from TD girls on the simple GNG task, but showed higher commission error rate and tau on the complex GNG task. These findings suggest that task complexity influences response control in children with ADHD in a sexually dimorphic manner. The findings have substantive implications for the pathophysiology of ADHD in boys versus girls with ADHD.     

The heterogeneity of attention‐deficit/hyperactivity disorder symptoms and conduct problems: Cognitive inhibition,emotion regulation,emotionality, and disorganized attachment

This study examined the contributions of several important domains of functioning to attention‐deficit/hyperactivity disorder (ADHD) symptoms and conduct problems. Specifically, we investigated whether cognitive inhibition, emotion regulation, emotionality, and disorganized attachment made independent and specific contributions to these externalizing behaviour problems from a multiple pathways perspective. The study included laboratory measures of cognitive inhibition and disorganized attachment in 184 typically developing children (M age = 6 years, 10 months, SD = 1.7). Parental ratings provided measures of emotion regulation, emotionality, and externalizing behaviour problems. Results revealed that cognitive inhibition, regulation of positive emotion, and positive emotionality were independently and specifically related to ADHD symptoms. Disorganized attachment and negative emotionality formed independent and specific relations to conduct problems. Our findings support the multiple pathways perspective on ADHD, with poor regulation of positive emotion and high positive emotionality making distinct contributions to ADHD symptoms. More specifically, our results support the proposal of a temperamentally based pathway to ADHD symptoms. The findings also indicate that disorganized attachment and negative emotionality constitute pathways specific to conduct problems rather than to ADHD symptoms.     

Reading Comprehension in Children with ADHD: Cognitive Underpinnings of the Centrality Deficit

We examined reading comprehension in children with ADHD by assessing their ability to build a coherent mental representation that allows them to recall central and peripheral information. We compared children with ADHD (mean age 9.78) to word reading-matched controls (mean age 9.89) on their ability to retell a passage. We found that even though children with ADHD recalled more central than peripheral information, they showed their greatest deficit, relative to controls, on central information—a centrality deficit (Miller and Keenan, Annals of Dyslexia 59:99–113, 2009). We explored the cognitive underpinnings of this deficit using regressions to compare how well cognitive factors (working memory, inhibition, processing speed, and IQ) predicted the ability to recall central information, after controlling for word reading ability, and whether these cognitive factors interacted with ADHD symptoms. Working memory accounted for the most unique variance. Although previous evidence for reading comprehension difficulties in children with ADHD have been mixed, this study suggests that even when word reading ability is controlled, children with ADHD have difficulty building a coherent mental representation, and this difficulty is likely related to deficits in working memory.     

A Clinical Comparative Study Evaluating the Effect of Epilepsy Versus Adhd on Timed Cognitive Tasks in Children

Both children with epilepsy and children with ADHD may be characterized by slowing on reaction-time measurement. This is of particular interest, as neuropsychological assessment is often requested in the differential diagnosis between children with short non-convulsive epileptic seizures and children with ADHD. In this study we attempt to identify patterns of impairment on timed tasks that are specific for epilepsy, relative to ADHD. This study was an open, controlled parallel-group clinical investigation which included two groups of patients: 60 children with ADHD and 60 children with epilepsy. These children were compared with a control group (n =30) on two types of timed cognitive tasks: tasks with low information load (simple reaction-time measurement) and tasks with high information load (multiple decision reaction-time measurement). The simple reaction-time measurements show significant differences between ADHD and controls (all except for visual RT non-dominant hand) and between epilepsy and controls (only one test). No significant differences were found between epilepsy and ADHD. The two tests with high information load show significant slowing compared with the controls for epilepsy on the Binary Choice Reaction-Time Test and for ADHD on the Visual Searching Test. On both tests also the differences between epilepsy and ADHD are significant. The two tests in combination have a relatively satisfactory potential to classify the children with ADHD (75% correct classification) and the children with epilepsy (55% correct classification). We may conclude that complex reaction-time tests (i.e., timed tasks with high information load) have potential for assessing the differential impact of ADHD and epilepsy on attentional function. These tasks specifically reveal general slowing for children with epilepsy and slowing as an effect of failures of inhibitory self control on unstructured tasks for ADHD.     

Virtual-reality-based attention assessment of ADHD: ClinicaVR: Classroom-CPT versus a traditional continuous performance test

Virtual-reality-based assessment may be a good alternative to classical or computerized neuropsychological assessment due to increased ecological validity. ClinicaVR: Classroom-CPT (VC) is a neuropsychological test embedded in virtual reality that is designed to assess attention deficits in children with attention deficit hyperactivity disorder (ADHD) or other conditions associated with impaired attention. The present study aimed to (1) investigate the diagnostic validity of VC in comparison to a traditional continuous performance test (CPT), (2) explore the task difficulty of VC, (3) address the effect of distractors on the performance of ADHD participants and typically-developing (TD) controls, and (4) compare the two measures on cognitive absorption. A total of 33 children diagnosed with ADHD and 42 TD children, aged between 7 and 13 years, participated in the study and were tested with a traditional CPT or with VC, along with several cognitive measures and an adapted version of the Cognitive Absorption Scale. A mixed multivariate analysis of covariance (MANCOVA) revealed that the children with ADHD performed worse on correct responses had more commissions and omissions errors than the TD children, as well as slower target reaction times . The results showed significant differences between performance in the virtual environment and the traditional computerized one, with longer reaction times in virtual reality. The data analysis highlighted the negative influence of auditory distractors on attention performance in the case of the children with ADHD, but not for the TD children. Finally, the two measures did not differ on the cognitive absorption perceived by the children.     

Hot and Cool Aspects of Cognitive Control in Children with ADHD: Decision-Making and Inhibition

This study investigated hot and cool aspects of cognitive control in children with Attention Deficit Hyperactivity Disorder (ADHD). The study aimed to: (1) replicate the postulated response inhibition deficit of children with ADHD; (2) explore whether children with ADHD choose disadvantageously in a decision-making task and to explore the mechanisms underlying the expected response pattern; and (3) study whether performance on a combination of hot and cool executive control measures has predictive value for an ADHD diagnosis. The sample consisted of 20 children with ADHD and 22 normal developing children (NC, 8 to 12 years) matched on age, FSIQ, and gender. Two paradigms have been applied: (1) the stop signal paradigm, and (2) the adapted children's version of the IOWA Gambling task. There were no group differences for both paradigms. Both groups chose in a reward-oriented manner and seemed to develop the ability to take future consequences into account in making decisions. Moreover, feedback resulted in direct behavioral changes. Children with ADHD did not have a specific response inhibition deficit or a decision-making deficit.     

Clinical,Sociobiological, and Cognitive Predictors of ADHD Persistence in Children Followed Prospectively Over Time

With increasing awareness that ADHD is chronically disabling, a burgeoning literature has examined childhood clinical indicators of ADHD persistence. This study investigates whether childhood factors reflecting biological risk and cognitive reserve have additive predictive value for the persistence of ADHD that is unique beyond childhood indicators of disorder severity. One-hundred thirty children with ADHD (mean age = 8.9 years, 75 % male) were followed into adolescence (mean age = 14.0 years). Childhood ADHD and co-morbidities were assessed via interviews with parents and teachers; parental psychopathology was assessed via parent interview; exposure to neurobiological and psychosocial adversity were indexed by parent questionnaire; and cognitive reserve was evaluated through children’s performance on measures of IQ and executive functioning. Univariate analyses identified childhood inattention and hyperactivity-impulsivity, co-morbid oppositional defiant disorder, overall impairment, and paternal anxiety and depression as more prevalent amongst adolescents with persistent compared with remitted ADHD. Only child-level predictors remained significant in a final multivariate model. These results suggest that children who are most likely to experience persistent ADHD have a more severe clinical presentation in childhood, reflected by increased levels of inattention, oppositional behavior, and impairment. They also are more likely to have fathers with internalizing concerns, but these concerns do not uniquely predict ADHD persistence beyond child-level factors. Contrary to expectations, childhood adversity and cognitive functioning did not predict the course of ADHD.     

External Validation of Bifactor Model of ADHD: Explaining Heterogeneity in Psychiatric Comorbidity,Cognitive Control,and Personality Trait Profiles Within DSM-IV ADHD

The current paper provides external validation of the bifactor model of ADHD by examining associations between ADHD latent factor/profile scores and external validation indices. 548 children (321 boys; 302 with ADHD), 6 to 18 years old, recruited from the community participated in a comprehensive diagnostic procedure. Mothers completed the Child Behavior Checklist, Early Adolescent Temperament Questionnaire, and California Q-Sort. Children completed the Stop and Trail-Making Task. Specific inattention was associated with depression/withdrawal, slower cognitive task performance, introversion, agreeableness, and high reactive control; specific hyperactivity-impulsivity was associated with rule-breaking/aggressive behavior, social problems, errors during set-shifting, extraversion, disagreeableness, and low reactive control. It is concluded that the bifactor model provides better explanation of heterogeneity within ADHD than DSM-IV ADHD symptom counts or subtypes.     

Processing Speed Deficits in Attention Deficit/Hyperactivity Disorder and Reading Disability

The goal of the current study was to test whether deficits in processing speed (PS) may be a shared cognitive risk factor in reading disability (RD) and Attention Deficit/Hyperactivity Disorder (ADHD), which are known to be comorbid. Literature on ADHD and RD suggests that deficits on tasks with a speeded component are seen in both of these disorders individually. The current study examined a wide range of speeded tasks in RD, ADHD, comorbid RD+ADHD, and a control group to test whether RD and ADHD have similar profiles of PS deficits, and whether these deficits are shared by the two disorders. The results suggest that a general PS deficit exists in both clinical groups compared to controls, although children with RD demonstrate greater PS deficits than children with ADHD. Two tests (underadditivity and partial correlations) were conducted to test whether these PS deficits are shared. Since we found that PS deficits were underadditive in the comorbid group and that partialling PS reduced the correlation between RD and ADHD, it appears that PS is a shared cognitive risk factor that may help explain the comorbidity of these two disorders.     

Are Motor Inhibition and Cognitive Flexibility Dead Ends in ADHD?

Executive dysfunction has been postulated as the core deficit in ADHD, although many deficits in lower order cognitive processes have also been identified. By obtaining an appropriate baseline of lower order cognitive functioning light may be shed on as to whether executive deficits result from problems in lower order and/or higher order cognitive processes. We examined motor inhibition and cognitive flexibility in relation to a baseline measure in 816 children from ADHD and control families. Multiple children in a family were tested in order to examine the familiality of the measures. No evidence was found for deficits in motor inhibition or cognitive flexibility in children with ADHD or their nonaffected siblings: Compared to their baseline speed and accuracy of responding, children with ADHD and their (non)affected siblings were not disproportionally slower or inaccurate when demands for motor inhibition or cognitive flexibility were added to the task. However, children with ADHD and their (non)affected siblings were overall less accurate than controls, which could not be attributed to differences in response speed. This suggests that inaccuracy of responding is characteristic of children having (a familial risk for) ADHD. Motor inhibition and cognitive flexibility as operationalized with mean reaction time were found to be familial. It is concluded that poorer performance on executive tasks in children with ADHD and their (non)affected siblings may result from deficiencies in lower order cognitive processes and not (only) from higher order cognitive processes/executive functions.     

Cognitive engagement and story comprehension in typically developing children and children with ADHD from preschool through elementary school

The present study examined children's cognitive engagement with television as a function of the continuity of central or incidental content and whether this varied with age and clinical status. In Experiment 1, 9- to 11-year-old children's response times on a secondary task were slower the later a probe occurred in a sequence of central events, and response times predicted recall. Experiment 2 extended these results to 6- to 8-year-old children. Experiment 3 revealed that children with attention-deficit/hyperactivity disorder (ADHD) failed to show the pattern consistently observed for comparison children. The results support the hypothesis that typically developing children build a representation during viewing that reflects the causal structure of the televised story but that this skill is deficient in 4- to 9-year-old children with ADHD.     

Sluggish Cognitive Tempo as a Transdiagnostic Link Between Adult ADHD and Internalizing Symptoms

Although absent from traditional diagnostic nosologies, Sluggish Cognitive Tempo (SCT) may have transdiagnostic utility given its robust associations with ADHD and internalizing symptoms as well as with cognitive impairments common to these conditions. Within-person variation in SCT symptoms may also serve to link ADHD, cognitive deficits, and internalizing psychopathology, however, few studies have utilized intensive longitudinal designs to probe within-person variation in SCT and its links to cognitive deficits and psychopathology. Ecological Momentary Assessment was used to measure between and within-person variance in SCT 4 times per day across 7 days (28 time-points) in 158 college students (approximately 51% with elevated ADHD and/or internalizing symptoms). Participants also completed ratings of current and childhood ADHD symptoms, cognitive function and internalizing psychopathology. Parameters derived from longitudinal multilevel models indexing between and within person variation in SCT were examined as mediators of the associations between (1) ADHD and internalizing symptoms and (2) self-reported cognitive functioning and internalizing symptoms. Results indicated that between-person differences in SCT, but not within-person variability, linked current and childhood ADHD and internalizing symptoms. Similarly, problems in time-management and organization influenced internalizing psychopathology via between-person differences in SCT. Results found that SCT may be a transdiagnostic link bridging mental health comorbidities, cognitive dysfunction, and internalizing psychopathology.