Does stimulant medication decrease the lower extremity response times of children with and without attention-deficit/hyperactivity disorder?

In 2005 Pedersen and Surburg reported that stimulant medications reduced the lower extremity response times of 16 boys with Attention-Deficit/Hyperactivity Disorder. However, as boys without ADHD and girls with and without ADHD were not studied, one cannot conclude that reported effects represent a medication effect unique to children with ADHD. An alternative hypothesis is presented: that stimulant medications produce an excitatory effect in the central nervous system by increased occupancy of postsynaptic dopamine receptors to reduce the lower extremity response times of children in general. Well-designed controlled clinical trials are needed to evaluate this hypothesis.     

Electroencephalographic responses to photic stimulation in habitual smokers and nonsmokers.

Two studies are reported in which electroencephalograms (EEGs) of habitual cigarette smokers and of nonsmokers were taken before and after they were required to smoke a cigarette. The EEGs were scored for incidence of EEG "driving" responses to photic stimulation, an index that appears to reflect the balance between central adrenergic and cholinergic nervous systems. The findings suggest that smokers tend to have a central autonomic balance less in favor of adrenergic functioning than do nonsmokers. Cigarette smoking may alleviate a possible central adrenergic insufficiency of smokers. These findings suggest a solution to "Nesbitt's paradox," which has reference to the fact that while nicotine is a central adrenergic stimulant, smokers describe the effect of smoking in sedational terms (i.e., as relaxing or calming).     

Play Behavior Differences Among Preschoolers with ADHD: Impact of Comorbid ODD and Anxiety

The acquisition of positive peer play behavior is an important aspect of child development and an indicator of social competence. Engaging in peer play may pose challenges for children with internalizing and externalizing disorders, particularly those with comorbid disorders. Existing literature contains little information on the peer play behaviors of children with attention-deficit/hyperactivity disorder (ADHD), and even less research is available examining the play behaviors of children with comorbid disorders. The present study assessed the peer play behaviors and social competence of 107 preschoolers with varying combinations of ADHD, oppositional defiant disorder (ODD), and anxiety symptoms. Assessment methods included direct observations and teacher ratings of child behavior. Results indicated there were no differences in observed peer play behaviors or negative behaviors toward peers, but there were differences in teacher-rated social competence between the groups. Results are discussed in terms of assessment method variations as well as directions for additional research in this critical area and implications for practice.     

Maternal ADHD: Parent-Child Interactions and Relations With Child Disruptive Behavior

This study examined how ADHD symptoms in mothers of children with ADHD relate to their behavior during parent-child interactions and to their children's disruptive behavior. Findings indicated that mothers’ retrospective self-ratings of ADHD symptoms were related to their present negativity during parent-led play. Mothers’ self-ratings of current inattentive symptoms were related to their impatience during child-led play. Maternal ADHD symptoms were also related to their ratings of their children's ADHD and oppositional-defiant behaviors. Identifying relations between maternal psychopathology, such as ADHD symptomatology, and behaviors during parent-child interactions may yield clues to additional parent behavioral changes that would enhance treatment outcomes for young children with ADHD.     

Attention,play, and social behavior in ADHD preschoolers

We investigated attention, play and nonplay behavior in preschool children with attention deficit hyperactivity disorder (ADHD) and a matched control group of non-ADHD children. Forty 4- to 5-year-old children (20 ADHD and 20 matched control) participated. Across a 6-week-period, children's social and play interactions as well as nonplay behaviors were videotaped in the classroom. Videotape recordings were analyzed for the level of attention, cognitive play, and social participation. In addition, children's level of attention and cooperative behavior were observed during two group activities. Findings indicated that ADHD, relative to non-ADHD, children engaged in less overall play and greater functional or sensorimotor play. ADHD children also engaged in more transitional behavior, were less competent with peers, and were less attentive and cooperative during group activities.This research was supported in part by an MCP grant awarded to Dr. Steven Alessandri. The author wishes to thank the children, parents, and the MCP/EPPI preschool staff for their assistance and cooperation.     

正念冥想在ADHD儿童干预中的应用

正念冥想是有意识、非评判地将注意集中于当下经验的方法。近年来,正念冥想作为一种潜在的方法被引进到ADHD儿童干预领域。因为ADHD儿童的特异性,为了增加正念冥想方案对ADHD儿童的适切性,研究者从练习设置、奖励系统、解释方式和家长纳入几个方面对标准的正念减压训练方案做了改编。越来越多的研究证据表明,正念冥想训练能有效地减轻ADHD儿童的核心缺陷、改善其内外化症状和亲子关系。本文通过对已有相关实证研究的分析认为这些积极的影响可能与ADHD儿童的执行功能与去中心化等心理功能的改善有关,而大脑相关区域激活模式的变化和结构的积极改变可能是正念冥想影响ADHD儿童的神经基础。文章也提出已有研究在内容和方法学上的不足及其以后的探究方向。     

Successful Child Psychotherapy of Attention Deficit/Hyperactive Disorder: An Agitated Depression Explanation

Science tries to explain phenomena in ways that are demonstrable and replicable to develop logical, coherent, parsimonious, and predictive theoretical systems. Yet hyperactive children are given stimulants to "calm" them down, despite the fact that science would predict stimulants would increase hyperactivity. Bradley (1937, 1950) observed that half of the behavior-problem children to whom he administered a stimulant for one week became subdued. He called this finding paradoxical, speculating that inhibitory centers of the central nervous system were stimulated. While Bradley's assertion of a paradoxical reverse effect in children may be an empirical observation, it is not an explanation. The Attention Deficit/Hyperactive Disorder (ADHD) is inferred to exist from hyperactive behavior, which in turn, is inferred to be neurological in origin, a circular argument. An inevitable consequence of the belief in the hypothetical neurological etiology of ADHD is that children are typically given stimulants. Using the case of a seven-year old child, described as experiencing ADHD, who was treated successfully without medication as an illustration, the author provides an alternative, more parsimonious explanation of the etiology, suggesting that ADHD is related to agitated depression.     

Responses to methylphenidate in Attention-Deficit/Hyperactivity Disorder and normal children: update 2002

Since the positive effects of stimulants on disruptive behavior were described (Bradley & Bowen, 1941), further pediatric studyhas been limited almost exclusively to samples of hyperkinetic school-age children. Because these agents normally were viewed as arousing in their effects on the central nervous system, but were calming in their therapeutic effects on these children, stimulant effects on Attention Deficit Disorder (ADD) were interpreted as being 'paradoxical.' Investigation of effects in normal children and adolescents and in those with disorders unrelated to Attention-Deficit/Hyperactivity Disorder (ADHD), as well as in young adult samples, however, indicate that stimulants appear to have similar behavioral effects in normal and in hyperactive children. This brief report is an update (as of August 2002) on studies of stimulants in ADHD and normal children, with particular focus on MPH.     

Does a Positive Bias Relate to Social Behavior in Children With ADHD?

This study examines whether positively biased self-perceptions relate to social behaviors in children with attention-deficit/hyperactivity disorder (ADHD) as compared to control children. The social behaviors of children with ADHD (n = 87) were examined relative to control children (CTL; n = 38) during a laboratory-based dyadic social interaction task. Children with ADHD were subgrouped into those with a positive illusory bias (PIB) in their self-perceptions (ADHD + PIB) versus those without such a bias (ADHD – PIB). Using a behavioral coding system adapted for this study, ADHD + PIB, ADHD – PIB, and CTL participants were compared on objectively coded social behaviors occurring within the context of the social interaction task. Whereas both ADHD groups displayed more disruptive behavior than controls, only the ADHD + PIB group displayed less prosocial behavior and less effortful behavior. This study breaks new ground by examining positively biased self-perceptions as they relate to social behavior in children with ADHD and provides promising new insight into the social problems experienced by these children.     

Modulatory role of serotonin in neural information processing: implications for human psychopathology.

Investigation of the role of 5-hydroxytryptophan (5-HT), which functions as a modulator in the central nervous system, across behavioral contexts suggests that a general principle of transmitter function may be derived that is independent of specific behaviors and specific neural loci. A functional principle of 5-HT action in neural information processing in the central nervous system is proposed. Extremes deviations in 5-HT activity result in biases in information processing that may have direct effects on behavior. Such biases may predispose to pathological conditions such as violent suicide and aggression.     

Changes in acetylcholine extracellular levels during cognitive processes

Measuring the changes in neurotransmitter extracellular levels in discrete brain areas is considered a tool for identifying the neuronal systems involved in specific behavioral responses or cognitive processes. Acetylcholine (ACh) is the first neurotransmitter whose diffusion from the central nervous system was investigated and whose extracellular levels variations were correlated to changes in neuronal activity. This was done initially by means of the cup technique and then by the microdialysis technique. The latter, notwithstanding some technical limitations, makes it possible to detect variations in extracellular levels of ACh in unrestrained, behaving animals. This review summarizes and discusses the results obtained investigating the changes in ACh release during performance of operant tasks, exposition to novel stimuli, locomotor activity, and the performance of spatial memory tasks, working memory, and place preference memory tasks. Activation of the forebrain cholinergic system has been demonstrated in many tasks and conditions in which the environment requires the animal to analyze novel stimuli that may represent a threat or offer a reward. The sustained cholinergic activation, demonstrated by high levels of extracellular ACh observed during the behavioral paradigms, indicates that many behaviors occur within or require the facilitation provided by the cholinergic system to the operation of pertinent neuronal pathways.     

Competing Core Processes in Attention-Deficit/Hyperactivity Disorder (ADHD): Do Working Memory Deficiencies Underlie Behavioral Inhibition Deficits?

The current study examined competing predictions of the working memory and behavioral inhibition models of ADHD. Behavioral inhibition was measured using a conventional stop-signal task, and central executive, phonological, and visuospatial working memory components (Baddeley 2007) were assessed in 14 children with ADHD and 13 typically developing (TD) children. Bootstrapped mediation analyses revealed that the visuospatial working memory system and central executive both mediated the relationship between group membership (ADHD, TD) and stop-signal task performance. Conversely, stop-signal task performance mediated the relationship between group membership and central executive processes, but was unable to account for the phonological and visuospatial storage/rehearsal deficits consistently found in children with ADHD. Comparison of effect size estimates for both models suggested that working memory deficits may underlie impaired stop-signal task performance in children with ADHD. The current findings therefore challenge existing models of ADHD that describe behavioral inhibition as a core deficit of the disorder.     

Online cognitive engagement of boys with ADHD

The present study was designed to examine the role that attentional problems may play in accounting for difficulties in story comprehension experienced by children with ADHD. A secondary task methodology was used to examine whether or not online variations in cognitive engagement with a televised story were related to the continuity of central or incidental information. Twenty-two 9- to 11 -year-old boys with ADHD and 36 of their nonreferred peers watched a television program and responded to auditory probes presented at preselected points during continuous sequences of central or incidental information. The reaction times to the probes for nonreferred boys showed the expected linear increase in cognitive engagement (i.e., the RTs increased) as central, plot-relevant sequences continued. In contrast, boys with ADHD showed the expected increase in RTs relatively late in the central sequences. The results were discussed in terms of how delays in engaging with central information may contribute to the academic difficulties experienced by boys with ADHD.     

The Relation Between Maternal Symptoms of Attention-Deficit/Hyperactivity Disorder and Mother–Infant Interaction

The relationship between maternal symptoms of attention-deficit/hyperactivity disorder (ADHD) and specific maternal behaviors was examined in a community sample of 40 mothers of infants aged 3–8 months. It was hypothesized that maternal ADHD symptoms would be related to lower levels of maternal sensitivity, and higher levels of maternal intrusiveness and negative regard. Mothers and their infants were observed and video-recorded in their homes while interacting in a feeding, play, and task situation. A series of hierarchical regressions partially supported the hypothesized relations: Of the specific maternal ADHD symptoms, maternal inattentive symptoms significantly predicted maternal insensitivity, intrusiveness, and negative regard above and beyond maternal symptoms of anxiety and maternal ratings of infant activity. These findings suggest that mothers reporting ADHD symptoms, particularly the inattentive cluster of symptoms, may experience difficulties in interactions with their infants. Early interventions that address these difficulties may be warranted to facilitate development and reduce the likelihood of adverse outcomes in children of mothers with symptoms of ADHD.     

Observed classroom behavior of children with ADHD: relationship to gender and comorbidity

Examined hypothesized gender and comorbidity differences in the observed classroom behavior of children with attention deficit hyperactivity disorder (ADHD). The behavior of 403 boys and 99 girls with ADHD, ages 7–10, was compared (a) to observed, sex-specific classroom behavior norms, (b) by sex, and (c) by comorbid subgroups. Boys and girls with ADHD deviated significantly from classroom norms on 15/16 and 13/16 categories, respectively. Compared to comparison girls, girls with ADHD had relatively high rates of verbal aggression to children. Boys with ADHD engaged in more rule-breaking and externalizing behaviors than did girls with ADHD, but the sexes did not differ on more neutral, unobtrusive behaviors. The sex differences are consistent with notions of why girls with ADHD are identified and referred later than boys. Contrary to hypothesis, the presence of comorbid anxiety disorder (ANX) was not associated with behavioral suppression; yet, as hypothesized, children with a comorbid disruptive behavior disorder (DBD) had higher rates of rule-breaking, and impulsive and aggressive behavior, than did children with ADHD alone and those with ADHD+ANX. Elevated rates of ADHD behaviors were also observed in children with comorbid DBD, indicating that these behaviors are truly present and suggesting that reports of higher ADHD ratings in this subgroup are not simply a consequence of negative halo effects and rater biases.     

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.     

Pre-existing Perceptions of ADHD Predict Children’s Sociometrics Given to Classmates with ADHD

Considerable research documents that even young children possess stigma about mental illness, which may affect how they evaluate peers with mental health conditions. This study examined children’s pre-existing perceptions of Attention Deficit/Hyperactivity Disorder (ADHD) behaviors as predictors of their subsequent sociometric judgments of classmates with ADHD in a 2-week summer day camp. Participants were previously unacquainted children ages 6.8–9.8 years (113 typically-developing and 24 with ADHD; 48.2% boys; 81% White). Children initially more inclined to interact with a hypothetical classmate with ADHD gave fewer “dislike” nominations to real-life classmates with ADHD at camp. Children who initially believed that ADHD symptoms were uncontrollable gave more “dislike” nominations and lower liking ratings to classmates with ADHD when those classmates displayed severe ADHD symptoms. For children who had ADHD, their attribution of uncontrollability for ADHD symptoms predicted fewer “like” nominations and more “dislike” nominations given to classmates with ADHD. Lastly, children who initially reported they would help a hypothetical classmate with ADHD gave higher liking ratings to classmates with ADHD. These results were found after statistical control of the actual level of ADHD behaviors displayed by the classmates with ADHD. In summary, other children’s pre-existing or stigmatizing perceptions of ADHD behaviors may contribute, in part, to the substantial peer rejection typically experienced by ADHD populations. Findings have implications for understanding peer problems in children with this common mental health condition.     

Testing the ability of children with attention deficit hyperactivity disorder to accurately report the effects of medication on their behavior

Children with attention deficit hyperactivity disorder (ADHD) are often treated with central nervous system stimulants, making the evaluation of medication effects an important topic for applied behavior analysts. Because assessment protocols emphasize informant reports and direct observations of child behavior, little is known about the extent to which children themselves can accurately report medication effects. Double-blind placebo-controlled procedures were used to examine whether 6 children with ADHD could recognize the effects of their medication. The children were given math worksheets to complete for 15 min during each of 14 sessions while on medication and placebo. Children completed a self-evaluation form at the end of each session, and ratings were compared to observed behavior and academic performance. Results indicated that 3 children were able to accurately report their medication status at levels greater than chance, whereas the accuracy of reports by all children was related to dosage level, differences in behavior, and the presence of adverse effects. The implications of these results for placebo-controlled research, self-monitoring of dosage levels, and accuracy training are discussed.     

Emotion Regulation via the Autonomic Nervous System in Children with Attention-Deficit/Hyperactivity Disorder (ADHD)

Despite growing interest in conceptualizing ADHD as involving disrupted emotion regulation, few studies have examined the physiological mechanisms related to emotion regulation in children with this disorder. This study examined parasympathetic and sympathetic nervous system reactivity via measures of respiratory sinus arrhythmia (RSA) and cardiac pre-ejection period (PEP) in children with ADHD (n = 32) and typically developing controls (n = 34), using a novel emotion task with four conditions: negative induction, negative suppression, positive induction, and positive suppression of affect. Both groups showed strong task-response effects in RSA. However, typically developing children showed systematic variation in parasympathetic activity (RSA) depending on both emotion valence (more activation for negative emotion, reduced activation for positive emotion) and task demand (more activation for suppression than induction). In contrast, children with ADHD displayed a stable pattern of elevated parasympathetic activity (RSA) across all task conditions compared to baseline. No group differences in sympathetic activity (PEP) were observed. It is concluded ADHD in childhood is associated with abnormal parasympathetic mechanisms involved in emotion regulation.     

7—10岁儿童不同亚型ADHD行为与共病问题

摘要：通过流行病学测查,探讨不同亚型ADHD儿童的情绪、行为和社会功能的差异。采用SDQ（长处与困难问卷）对4500名7-10岁儿童进行大样本筛查,应用K-SADS-PL量表和DSM-Ⅳ诊断标准对其中263名高危儿童进行临床评估,诊断出119名儿童ADHD。诊断出的ADHD儿童中,男性与女性的比率大约为2.22︰1,存在显著的性别差异。混合型儿童ADHD的多动性不能得分显著高于注意缺陷性;混合型ADHD的社会功能得分显著低于注意缺陷型和多动型。7岁儿童ADHD的多动情况显著低于8岁、9岁。ADHD共病率为12.6%,ADHD儿童伴有学习困难的比例为43.2%。