Inge Antrop

Stimulation Seeking and Hyperactivity in Children with ADHD

Thirty hyperactive and 30 non-hyperactive children were confronted with a delay, consisting of a waiting situation of 15 minutes, either with or without extra stimulation provided by the presentation of a videotape. The behaviour of the child during the waiting period was videotaped and later coded by two naive observers. In line with theories that emphasise the stimulation-seeking function of hyperactive behaviours, such as the optimal stimulation account and the delay aversion theory, a group by stimulation effect was hypothesised. For two categories of activity this was found, with ADHD children displaying more activity than non-ADHD children in the no-stimulation but not in the stimulation condition. These data provide support for the stimulation-seeking function of certain features of ADHD hyperactivity.

Agreement between parent and teacher ratings of disruptive behavior disorders in children with clinically diagnosed ADHD.

This study investigated the agreement between parent and teacher ratings of DSM-IV symptoms of Attention Deficit Hyperactivity Disorder (ADHD) and related disorders: Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD). A sample of 55 children in the age range of 6–12 years with clinically diagnosed ADHD participated in the study. Parents and teachers were asked to complete the Disruptive Behavior Disorder Rating Scale (DBDRS; W. E., Pelham, E. M., Gnagy, K. E., Greenslade, & R. Milich, 1992). No association was found between parent and teacher ratings of inattention and hyperactivity/impulsivity. However, moderate to high levels of agreement were obtained for ratings of symptoms that characterized ODD and CD. The observed low levels of agreement between parent and teacher ratings of ADHD symptoms may be attributed to different perceptions of the problem behavior by parents and teachers, medication effects, or the situation specificity of childrens behavior. It is recommended that the diagnostic criterion of symptom pervasiveness for the diagnosis of ADHD be operationalized more clearly.

State Regulation in Adult ADHD : An Event-related Potential Study

The state regulation hypothesis postulates that poor task performance of children with ADHD is related to poor energetical state control. The current study aimed to investigate whether such a deficit persists in adult ADHD. Event-related potentials (ERPs) were recorded during administration of a Go/No-Go task that incorporated the stressor presentation rate of stimuli. It was found that males with ADHD responded slower than control males in the slow condition, which was accompanied by smaller parietal P3s, suggesting less effort allocation. No group differences were found with respect to the response inhibition measures (errors of commission and the N2 effect). In conclusion, problems in state regulation seem to persist in male adults with ADHD.

Altered circadian profiles in attention-deficit/hyperactivity disorder: An integrative review and theoretical framework for future studies

Disruptions in the sleep-wake cycle and the circadian system have been found in a wide range of psychiatric disorders and are generally correlated with clinical severity and diminished quality of life. Emerging evidence suggests similar disturbances may be found in attention-deficit/hyperactivity disorder (ADHD). Here we review the available literature on across the day fluctuations in ADHD-related processes in terms of; (i) time of day effects on behavior and activity; (ii) morningness-eveningness chronotypology; (iii) sleep/wake rhythms; and (iv) rhythmicity in neuroendocrine and neurophysiological responsiveness. On this basis, we propose a neurobiological framework to guide future study, which sees circadian effects in ADHD, along with other aspects of ADHD arousal-related deficits (e.g., cognitive energetic deficits), as being the result of dysregulated locus coeruleus function. Based on this perspective specific recommendations for future research are presented.

HFA and ADHD: A direct comparison on state regulation and response inhibition

This study examined whether children with high-functioning autism (HFA) are easily overaroused/activated and whether children with attention-deficit/hyperactivity disorder (ADHD) are easily underaroused/activated. This double dissociation was tested using a go/no-go paradigm with computer-paced fast and slow conditions and a self-paced condition. In the HFA group, a performance decline in the fast condition and slow performance in the self-paced condition were expected. In the ADHD group, a performance decline in the slow condition and fast performance in the self-paced condition were expected. No difference was found between groups for state regulation and response inhibition. Findings are discussed in the light of development, comorbidity, and subtypes.

The impact of attention deficit hyperactivity disorders on brainstem dysfunction in nocturnal enuresis

PURPOSE In a specialized university setting the prevalence of attention deficit hyperactivity disorder in general and particularly the inattentive subtype attention deficit hyperactivity disorder of the predominantly inattentive subtype is highly increased. We replicated previous research findings that enuresis is associated with a brainstem deficit and investigated the impact of attention deficit hyperactivity disorder on this brainstem deficit in enuresis. MATERIALS AND METHODS Electromyography recorded startle eye blink modification with and without attentional modulation was used to measure brainstem functioning in 158 children between 6 and 12 years old. Performance in 3 enuresis groups, including children with enuresis, enuresis plus attention deficit hyperactivity disorder of the predominantly inattentive subtype and enuresis plus attention deficit hyperactivity disorder combined, respectively, was compared with that in normally developing controls and in children with attention deficit hyperactivity disorder subtypes without enuresis. RESULTS In an automatic attentional task the enuresis groups showed decreased brainstem inhibition compared to that in the control and attention deficit hyperactivity disorder groups (p <0.006). In a controlled attentional task children with and without enuresis who had attention deficit hyperactivity disorder of the predominantly inattentive subtype were unable to show attentional modulation in all age groups (p <0.02). CONCLUSIONS Startle eye blink modification research reveals a brainstem inhibition deficit in children with enuresis, which could explain why they are unable to remain dry at night. When additional attention is allocated to specific trials in the task, children with attention deficit hyperactivity disorder of the predominantly inattentive subtype fail to optimize sensory gating. With respect to enuresis, this could result in an identification problem of bladder signals, leading to an inadequate or absent arousal effect in attention deficit hyperactivity disorder of the predominantly inattentive subtype.

Probing the limits of delay intolerance : Preliminary young adult data from the Delay Frustration Task (DeFT)

Delay intolerance/aversion is one amongst a number of candidate neuropsychological endophenotypes for ADHD. Pilot data suggest that, because of potential ceiling effects, simple choice measures of delay tolerance used for children are probably not appropriate for adolescents and adults. The Delay Frustration Task (DeFT) is a new measure of delay intolerance, designed to be used in a similar form with adolescents and adults as well as children. In it delay frustration is indexed as the number and duration of responses made on a response key during a series of unpredictable and unsignalled delay periods, which interrupt the completion of a simple computer-based tests. The aim of this study was to provide preliminary data on the applicability of the task in a sample of young adults. The DeFT was administered to 49 male and female undergraduate students selected from a normal population-base. Their mean age was 23.14 (S.D.=1.54). Three measures of delay frustration were recorded across time intervals during the response window; the number of responses, their duration and their combined product (total time button was pressed) was calculated for each second interval bin during the post-response delay period. The AARS and HADS were used as screening questionnaires for ADHD and anxiety behaviour, respectively. The results indicated that young adults with high-ADHD symptoms scores pressed the button more than those with low ADHD scores during the post-response delay condition. While both groups increased responding across time within intervals this was significantly more marked in the high-ADHD symptom group. These effects became more pronounced when anxiety was controlled. Young adults with high-ADHD symptoms appear to be more sensitive to the imposition of unscheduled and unsignalled delay during a simple maths test. DeFT may provide a useful index of delay tolerance in young adults with ADHD. Future research needs to examine DeFT performance in different age groups and in clinical and non-clinical populations.

Activity in children with ADHD during waiting situations in the classroom: a pilot study

BACKGROUND According to the optimal stimulation theory and the delay aversion hypothesis, children with attention deficit hyperactivity disorder (ADHD) experience difficulties when they are confronted with low levels of stimulation and delay, respectively. AIM This study investigated the activity level of children with ADHD during waiting situations in the classroom. Three series of hypothesis were made: (1) with respect to the comparison between waiting and non-waiting intervals, (2) with respect to the effects of non-temporal stimulation, and (3) with respect to the effects of temporal stimulation on behaviour during waiting. SAMPLE AND METHOD The activity level of 14 children with ADHD and 14 control children between the ages of 6 and 11 years was observed during two non-waiting class situations and three waiting situations: without any stimulation, in the presence of nontemporal stimulation and in the presence of temporal stimulation. RESULTS Both groups of children obtained higher activity scores for all behavioural dimensions during waiting compared with non-waiting situations. The results further revealed additive effects of waiting and diagnostic group on behaviour. Additional nontemporal stimulation during waiting affected the behaviour of all children for most behavioural characteristics. For noisiness, additive effects were also found for diagnostic group and either non-temporal stimulation or temporal stimulation. For restlessness, a trend for an interaction effect between diagnostic group and nontemporal stimulation was found. CONCLUSION The findings have clear implications for school observations within an assessment protocol.

Effects of Time of Day on Classroom Behaviour in Children with ADHD

To examine the effects of time of day and playtime on hyperactive behaviour in children with ADHD, 14 boys with ADHD and 14 control children were observed and videotaped during a whole school day. Analyses reveal minor differential effects of time of day and playtime on the hyperactive behaviour of children with ADHD compared to control children for noisiness and out of seat behaviour. Children with ADHD show a stronger increase in hyperactive behaviour after playtime in the afternoon. These differential effects are important in the light of the management of children with ADHD in the classroom and of observations that commonly take place for both diagnosis and research.

Time-of-day effects in arousal: disrupted diurnal cortisol profiles in children with ADHD

BACKGROUND   Fluctuations in attention-deficit hyperactivity disorder (ADHD) symptoms related to regulatory deficits in arousal states are themselves characterized by circadian rhythms. Although cortisol is an important circadian arousal-related marker, studies focusing on across-the-day cortisol variations in ADHD are scarce. There is no study with multiple measurements to take into account interday and intraday variability. METHODS   Salivary cortisol was sampled five times a day (awakening, 30 min after awakening, noon, 4 p.m., 8 p.m.) across five consecutive days in 33 children with ADHD (22 with and 11 without oppositional defiant disorder; ODD) and 33 class- and sex-matched controls (aged 6-12). The cortisol awakening response (increase from awakening to 30 min after awakening) and the diurnal cortisol profile (across-the-day variations) were compared for ADHD with ODD (ADHD + ODD) and without ODD (ADHD) subgroups and the control group. RESULTS   The cortisol awakening response was not significantly different between groups. However, longitudinal analyses to evaluate cortisol profiles across the day revealed a significant Group × Time effect (p < .001). More specifically, compared to each other, the ADHD subgroup showed a flatter slope with relative morning hypo-arousal and evening hyperarousal, whereas the ADHD + ODD subgroup showed a steeper slope with relative morning hyperarousal and evening hypo-arousal (p < .001). CONCLUSIONS   Findings support time-related arousal disruptions in children with ADHD associated with the presence or absence of ODD comorbidity. We recommend research on cortisol in larger samples for a better understanding of arousal mechanisms involved in ADHD not only with and without ODD but also with other comorbidities which may have implications for timing of arousal-based treatments.