Response execution and inhibitionin children with AD/HD and other disruptive disorders: the role of behavioural activation.

Item does not contain fulltextThis study was aimed at (a) replicating findings of slow and variable response execution and slow response inhibition in Attention Deficit/Hyperactivity Disorder (AD/HD), (b) investigating whether these deficits are specifically related to AD/HD or may also be observed in Oppositional Defiant Disorder (ODD), and children comorbid for AD/HD+ODD, and (c) examining the role of activation level in task performance of children with AD/HD. To meet these aims, the stop paradigm was administered at three levels of activation, using a slow, medium, and fast presentation rate of stimuli, to 4 groups of children: 24 AD/HD children, 21 children with ODD, 27 children with comorbid AD/HD+ODD, and 41 normal controls. As hypothesized, children with AD/HD exhibited a slow response execution process with considerable variability in the speed of responding compared to normal controls. Slow response execution was also observed in the comorbid AD/HD+ODD group but not in the pure ODD group. Larger variability in the speed of responding was common to all disruptive groups compared with controls. In contrast to our hypothesis, no group differences emerged for inhibitory functioning. Finally, the slow event rate condition caused a further deterioration in the speed of the response execution process in both the AD/HD group and ODD group

Speed of inhibition predicts teacher-rated medication response in boys with attention deficit hyperactivity disorder

Item does not contain fulltextThis study aimed at investigating whether one of the key deficits in Attention Deficit Hyperactivity Disorder (ADHD), slow response inhibition, predicted the response to methylphenidate (MPH) treatment. In order to address this issue, we used Stop Signal Reaction Times (SSRTs) measured at baseline in 20 medication-nave boys with ADHD as predictor, and parent and teacher ratings that were collected during a double-blind, placebo-controlled titration trial of MPH in the same group as outcome measures. Parent and teacher ratings were collected on primary scales, measuring ADHD symptoms, and secondary scales, measuring oppositional and disruptive behaviour. Placebo response and ADHD/Oppositional Defiant Disorder symptom severity at baseline were controlled for in the analyses. The SSRT did not predict the MPH response as measured by parent ratings, but it did predict the MPH response as measured by teacher ratings. This effect was specific for the ADHD scales. The slower SSRTs were, the less children benefited from MPH. Moreover, children with longer SSRTs needed higher doses of MPH for optimal symptom relief than children with shorter SSRTs. These findings have implications for clinicians who face the decision of which MPH dose to prescribe.18 p

Response Inhibition in Children With DSM-IV Subtypes of AD/HD and Related Disruptive Disorders: The Role of Reward

Item does not contain fulltextThe current study had four aims: (a) to replicate previous findings of slow response inhibition in Attention Deficit/Hyperactivity Disorder (AD/HD), (b) to explore whether poor response inhibition in children with AD/HD is a core problem or rather a result of an underlying problem related to reward, (c) to investigate the specificity of poor response inhibition and the role of reward in relation to AD/HD, and (d) to study whether findings would be different for three subtypes of AD/HD. In order to address these issues, a stop paradigm was administered under a reward condition and under a nonreward condition to an AD/HD group (n = 24), an Oppositional Defiant Disorder (ODD)/Conduct Disorder (CD) group (n = 21), a comorbid AD/HD + ODD/CD group (n = 27), and a normal control (NC) group (n = 41). Firstly, contrary to prediction, none of the Disruptive Behavior Disorder (DBD) groups differed from the NC group with respect to the speed of the inhibition process. Secondly, it was shown that children with AD/HD and children with comorbid AD/HD + ODD/CD, but not children with ODD/CD alone, slowed down more dramatically in the reward condition than normal controls. This finding was interpreted as a strategy to increase the chance of being rewarded in children with AD/HD and children with comorbid AD/HD + ODD/CD, but not in children with pure ODD/CD. Finally, analysis of AD/HD subtypes did not change the main findings of this study

Test-retest reliability of a new delay aversion task and executive function measure.

Despite the wide adoption of measures of executive functions and motivational tendencies in studies of developmental disorders and child psychopathology, few studies have investigated their test-retest reliability. The present paper examines the reliability of a new measure of delay aversion, three measures of working memory, a response inhibition measure and a measure of dual task performance. The children, aged between 7 and 15 years, performed the tasks twice, with a 2-week period in between the sessions. Using a relatively conservative criterion, only the delay aversion task and one of the working memory measures (delayed response alternation) demonstrated satisfactory test-retest reliability. The other two working memory measures (sentence span and counting span) showed modest reliability. For the inhibition measure (stop task) the results were mixed, with poor to modest reliabilities obtained for the various derived measures. The dual task failed to demonstrate adequate test-retest reliability. These differential reliabilities need to be borne in mind when interpreting the results of studies using these measures. In particular the effect of low reliability on statistical power and the Type II error rate should be considered

Executive functioning in adult ADHD: a meta-analytic review

. CONCLUSIONS: Neuropsychological difficulties in adult ADHD may not be confined to executive functioning. The field is in urgent need of better-designed executive functioning tests, methodological improvements, and direct comparisons with multiple clinical groups to answer questions of specificit

Finding the attractor of anger: Bridging the gap between dynamic concepts and empirical data

Although it accounts for the prototypical course of emotions, the attractor concept has hardly ever been used empirically. Authors applied Empirical Differential Equations (EDE) to frequent (hourly) anger ratings to find the attractor of anger. The attractor concept, its neurological basis, and EDE are explained. The attractor of anger follows an underdamped oscillator, and is affected by the capacity to inhibit prepotent responses. Anger accelerates less fast when inhibitory control increases. Results stress the internal dynamics of emotions, and help to bridge the gap between concepts from dynamic systems theory and empirical dat

Error and post-error processing in children with attention-deficit/hyperactivity disorder:An electrical neuroimaging study

Objective: Inaccurate and inconsistent response styles in attention-deficit/hyperactivity disorder (ADHD) have been observed in a wide variety of cognitive tasks, in line with regulatory deficit models of ADHD. Event-related potential (ERP) studies of error processing have provided evidence for these models, but are limited in specificity. We aimed to improve the isolation, localization and identification of error (self-monitoring and adaptive control) and post-error (implementation of cognitive control) processing in ADHD. Methods: ERPs were obtained for 46 ADHD and 51 typically developing (TD) children using the stop-signal task. Response-locked error (Ne and Pe) and stimulus-locked post-error (N2) components were compared between groups. Ne/Pe were corrected for preceding stimulus overlap and group differences were localized. Results: Ne was intact, while Pe amplitude was markedly reduced in children with ADHD (ηp2 = 0.14). Pe differences were localized in the dorsal posterior/midcingulate (BA31/24) cortex. While the TD group showed increased N2 amplitude in post-error trials (ηp2 = 0.24), localized in the left ventrolateral prefrontal cortex (VLPFC) and angular gyrus, the ADHD group did not. Conclusions: Self-regulation deficits in ADHD are associated with later stages of error processing and subsequent implementation of cognitive control. Significance: We contribute to the literature by further specifying error processing deficits in ADHD

Substance use disorders in adolescents with attention deficit hyperactivity disorder: a 4-year follow-up study

Aim To examine the relationship between a childhood diagnosis of attention deficit hyperactivity disorder (ADHD) with or without oppositional defiant disorder (ODD)/conduct disorder (CD) and the development of later alcohol/drug use disorder [psychoactive substance use disorder (PSUD)] and nicotine dependence in a large European sample of ADHD probands, their siblings and healthy control subjects. Participants design and settingSubjects (n=1017) were participants in the Belgian, Dutch and German part of the International Multicenter ADHD Genetics (IMAGE) study. IMAGE families were identified through ADHD probands aged 5-17 years attending out-patient clinics, and control subjects from the same geographic areas. After a follow-up period (mean: 4.4 years) this subsample was re-assessed at a mean age of 16.4 years. Measurements PSUD and nicotine dependence were assessed using the Diagnostic Interview Schedule for Children, Alcohol Use Disorders Identification Test, Drug Abuse Screening Test and Fagerstrom test for Nicotine Dependence. Findings The ADHD sample was at higher risk of developing PSUD [hazard ratio (HR)=1.77, 95% confidence interval (CI)=1.05-3.00] and nicotine dependence (HR=8.61, 95% CI=2.44-30.34) than healthy controls. The rates of these disorders were highest for ADHD youth who also had CD, but could not be accounted for by this comorbidity. We did not find an increased risk of developing PSUD (HR=1.18, 95% CI=0.62-2.27) or nicotine dependence (HR=1.89, 95% CI=0.46-7.77) among unaffected siblings of ADHD youth. Conclusions A childhood diagnosis of attention deficit hyperactivity disorder is a risk factor for psychoactive substance use disorder and nicotine dependence in adolescence and comorbid conduct disorder, but not oppositional defiant disorder, further increases the risk of developing psychoactive substance use disorder and nicotine dependence

ADHD subtypes: do they differ in their executive functioning profile?

The present study was designed to investigate the hypothesis that children with Attention Deficit Hyperactivity Disorder combined subtype (ADHD-C) have a generalized executive functioning (EF) [Barkley, R. A. (1997). Behavioural inhibition, sustained attention, and executive functions: Constructing a unifying theory of AD/HD. Psychological Bulletin, 121, 65-94; Barkley, R. A. (1997). ADHD and the nature of self-control. New York: The Guilford Press]. We tested whether ADHD-C and ADHD inattentive subtype (ADHD-I) can be differentiated from each other on EF measures. We compared 16 normally developing boys with 16 boys with ADHD-C and 16 with ADHD-I on five EF domains. The boys were all matched on age, IQ, and the presence of oppositional defiant disorder (ODD)/conduct disorder (CD). Despite carefully diagnosed groups and methodological controls, the results do not support the EF-hypothesis of ADHD-C. Children with ADHD-C differed from normal controls (NC) on tasks related to inhibition; they did not exhibit EF deficits on all EF tasks. Children with ADHD-C also exhibited deficits on non-EF tasks. Furthermore, the ADHD-C and ADHD-I subtypes did not differ from one another. Neuropsychological findings on the domains under study did not yield evidence for the distinctiveness of ADHD-C and ADHD-I subtypes. © 2004 National Academy of Neuropsychology. Published by Elsevier Ltd. All rights reserved

Treatment of Attention Deficit Hyperactivity Disorder in Children: Predictors of Treatment Outcome

Objective: The present study investigated the predictive power of anxiety, IQ, severity of ADHD and parental depression on the outcome of treatment in children with ADHD. Method: Fifty children with ADHD (ages 8-12) were randomized to a 10-week treatment of methylphenidate or to a treatment of methylphenidate combined with multimodal behavior therapy. Prior to treatment predictors were assessed. Outcome was assessed separately for parents and teachers on a composite measure of inattentive, hyperactive, oppositional- and conduct disorder symptoms. Results: There was neither a significant difference between the two treatments at baseline nor did treatment condition predict outcome. Therefore the data were collapsed across the two treatments. A combination of anxiety and IQ predicted teacher-rated outcome, explaining 18% of the variance. Higher anxiety and higher IQ's indicated better treatment outcome. There were no significant predictors of the parent-rated outcome. Conclusions: This study showed a small but significant predictive effect of IQ and anxiety on treatment outcome in children with ADHD. Clinical Clinical: This study supports the idea that for the treatment of ADHD children with comorbid anxiety and higher IQ respond better to the two most used treatments for ADHD. © 2007 Steinkopff Verlag