注意缺陷多动障碍的神经机制及干预

注意缺陷多动障碍是一种常见的神经性、发展性障碍。大脑异常被认为是注意缺陷多动障碍的病因之一。随着脑成像技术的发展,当前对该障碍的脑解剖结构病变、脑神经发育迟缓和脑网络连接异常等方面都展开了深入研究。文章从以上三个方面介绍最新研究成果,并指出目前的不足和未来研究方向,在此基础上为提高诊断精确性和发展新型有效的治疗干预方法提供建议。     

Parental involvement in children's learning: Comparing parents of children with and without Attention-Deficit/Hyperactivity Disorder (ADHD)

The present study examined involvement in children's learning among parents of 101 children between 8 and 12 years of age (53 parents of children with ADHD, 48 parents of children without ADHD). Compared to parents of children without ADHD, parents of children with ADHD reported lower self-efficacy in their ability to help their children, felt less welcome and supported by their children's schools and teachers, and perceived less time and energy for involvement in their children's academic lives. Mothers of children with and without ADHD reported similar types and levels of involvement behaviors in the home. Fathers of children with ADHD reported being more disengaged from their children's learning and using more coercive and punitive interactions regarding their children's achievement compared to fathers of children without ADHD. These findings underscore the difficulties in parent-supported learning practices and home-school collaboration initiatives faced by parents of children with ADHD and educators alike. Implications for school psychology practice are discussed.     

Empathy and Social Perspective Taking in Children with Attention-Deficit/Hyperactivity Disorder

This study explored empathy and social perspective taking in 8 to 12 year old children with and without Attention-Deficit/Hyperactivity Disorder (ADHD). The sample comprised 92 children, 50 with a diagnosis of ADHD and 42 typically developing comparison children. Although children with ADHD were rated by their parents as less empathic than children without ADHD, this difference was accounted for by co-occurring oppositional and conduct problems among children in the ADHD sample. Children with ADHD used lower levels of social perspective taking coordination in their definition of problems, identification of feelings, and evaluation of outcomes than children without ADHD, and these differences persisted after the role of language abilities, intelligence and oppositional and conduct problems were taken into account. Girls were more empathic and had higher overall social perspective taking scores than boys. Implications for research and practice are discussed. This research was funded by the Social Sciences and Humanities Research Council (SSHRC).     

Parenting,Family Loneliness,and Peer Functioning in Boys with Attention-Deficit/Hyperactivity Disorder

The goal of the present study was to consider the associations between family functioning (parenting and family loneliness) and peer functioning in a sample of boys with ADHD (N = 110) and their mothers (N = 108) and fathers (N = 53). Results indicated that higher paternal warmth was associated with more peer acceptance, less peer rejection, and less problematic social behavior, but only for boys who reported low levels of family loneliness. In addition, more paternal power assertion was related to less peer acceptance, but only for boys who reported low levels of family loneliness. Maternal warmth and power assertion were not significantly related to boys' peer functioning. We discuss these findings in the context of the processes by which parenting may affect the peer relationships of these children.     

Etiologic Subtypes of Attention-Deficit/Hyperactivity Disorder: Brain Imaging, Molecular Genetic and Environmental Factors and the Dopamine Hypothesis

Multiple theories of Attention-Deficit/Hyper- activity Disorder (ADHD) have been proposed, but one that has stood the test of time is the dopamine deficit theory. We review the narrow literature from recent brain imaging and molecular genetic studies that has improved our understanding of the role of dopamine in manifestation of symptoms of ADHD, performance deficits on neuropsychological tasks, and response to stimulant medication that constitutes the most common treatment of this disorder. First, we consider evidence of the presence of dopamine deficits based on the recent literature that (1) confirms abnormalities in dopamine-modulated frontal-striatal circuits, reflected by size (smaller-than-average components) and function (hypoactivation); (2) clarifies the agonist effects of stimulant medication on dopaminergic mechanisms at the synaptic and circuit level of analysis; and (3) challenges the most-widely accepted ADHD-related neural abnormality in the dopamine system (higher-than-normal dopamine transporter [DAT] density). Second, we discuss possible genetic etiologies of dopamine deficits based on recent molecular genetic literature, including (1) multiple replications that confirm the association of ADHD with candidate genes related to the dopamine receptor D4 (DRD4) and the DAT; (2) replication of differences in performance of neuropsychological tasks as a function of the DRD4 genotype; and (3) multiple genome-wide linkage scans that demonstrate the limitations of this method when applied to complex disorders but implicate additional genes that may contribute to the genetic basis of ADHD. Third, we review possible environmental etiologies of dopamine deficits based on recent studies of (1) toxic substances that may affect the dopamine system in early development and contribute substantially to the etiology of ADHD; (2) fetal adaptations in dopamine systems in response to stress that may alter early development with lasting effects, as proposed by the developmental origins of health and disease hypothesis; and (3) gene-environment interactions that may moderate selective damage or adaptation of dopamine neurons. Based on these reviews, we identify critical issues about etiologic subtypes of ADHD that may involve dopamine, discuss methods that could be used to address these issues, and review old and new theories that may direct research in this area in the future.     

Cigarette Smoking Among Youth with Attention-Deficit/Hyperactivity Disorder: Clinical Phenomenology, Comorbidity, and Genetics

Cigarette smoking and other forms of tobacco use among children and adolescents is a significant public health concern. The negative consequences of prolonged exposure to such substances are numerous, and include higher prevalence rates of cardiopulmonary dysfunction and certain cancers, and may lead to other forms of drug use. Identifying subgroups of youth who may be at greater risk than others to develop a nicotine habit is an important step forward in preventing smoking initiation, and controlling tobacco use. One such subgroup is children with attention-deficit/hyperactivity disorder (ADHD). This is because the prevalence of smoking among these youngsters is nearly twice as high as it is among those who are unaffected with ADHD. However, the etiology of this association is not known. It is possible that a constellation of social, behavioral, and biological factors influences this process, resulting in higher prevalence rates. To further our understanding of this problem, we reviewed each of these factors in relationship to smoking and to ADHD. Using the primary care population as a model, we then discuss clinical research methods that may shed additional light on this topic, as well as the strengths and limitations of current smoking prevention and cessation options for ADHD-affected youth who are assessed and treated in medical settings.     

阅读障碍与注意缺陷多动障碍儿童的语言加工和反应抑制

阅读障碍与注意缺陷多动障碍(ADHD)高度共病,以往研究结果显示两种障碍在语言加工、执行功能等领域的缺陷既相似又不同。本研究采用语音意识测验、快速命名测验、语素意识测验和停止信号任务,以及阅读广度测验,分别考察四组被试（阅读障碍组、ADHD组、双重障碍组、正常控制组）的基础语言加工、反应抑制和言语工作记忆能力,结果发现：阅读障碍组和双重障碍组在语言加工任务上的成绩均显著差于ADHD组和正常组;ADHD组和双重障碍组在停止信号任务上的成绩显著差于阅读障碍组和正常组;所有障碍组在阅读广度测验上的成绩显著差于正常组。表明阅读障碍的特异性缺陷体现在语言加工过程上,而注意缺陷多动障碍的特异性缺陷体现在反应抑制上。这对于今后单一障碍的研究及临床诊断和干预具有重要的参考价值。     

Adrenocortical Functioning in Boys with Attention-Deficit/Hyperactivity Disorder: Examining Subtypes of ADHD and Associated Comorbid Conditions

Disruptions to hypothalamic-pituitary-adrenal (HPA) axis function have been associated with varying forms of psychopathology in children. Studies suggesting children with ADHD have blunted HPA function have been complicated by the prevalence of comorbid diagnoses and heterogeneity of ADHD. The goals of this research were to assess the relations between waking and stress–response salivary cortisol levels and comorbid disruptive behavior (DBD) and anxiety (AnxD) disorders and problems in boys with ADHD, and to examine whether cortisol levels varied across ADHD subtypes. One hundred seventy elementary school-age boys with ADHD provided salivary cortisol at waking and in reaction to venipuncture. Parent reports were used to assess boys’ psychiatric diagnoses and severity of behavioral problems. Boys’ comorbid AnxD and anxiety problems were associated with greater cortisol reactivity, whereas boys’ comorbid DBD and oppositional problems predicted diminished adrenocortical activity. Reactive cortisol increases were greatest in boys with ADHD and comorbid AnxD, but without DBD. ADHD subtypes were not differentially associated with waking, pre-stress baseline, or reactive cortisol levels. However, comorbid DBD predicted decreased cortisol reactivity in boys with inattentive and hyperactive subtypes of ADHD, but not in boys with combined subtype of ADHD. The results clarify previous patterns of distinct and divergent dysregulations of HPA function associated with boys’ varying kinds of psychopathology.

Parent and Teacher Ratings of Attention-Deficit/Hyperactivity Disorder in Preschool: The ADHD Rating Scale-IV Preschool Version

Efforts for early identification and intervention for children with AD/HD have necessitated the development of rating scales of behavior for the preschool population. The standardization, reliability, and validity data were presented for the ADHD Rating Scale-IV Preschool Version. Parent and teacher ratings were collected on 902 and 977 children 3 to 5 years of age, respectively. Raw scores for the Inattention, Hyperactivity/Impulsivity and Total scores were converted to T-Scores and percentile ranks. Reliability coefficients ranged from 0.80 to 0.95 indicating good test–retest reliability. Concurrent validity with the Conners Teacher Rating Scales: Revised-Short and Conners Parent Rating Scale: Revised-Short ranged from 0.54 to 0.96. The ADHD-Rating Scale-IV appears to be a reliable, valid and user friendly measure for screening preschoolers with behavior problems. Future research is needed to validate its widespread use as a screening and diagnostic tool.     

Clinical and functional correlates of processing speed in pediatric Attention-Deficit/Hyperactivity Disorder: a systematic review and meta-analysis

It is well established that processing speed is negatively impacted in children and adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD). Unfortunately, exactly how processing speed vulnerabilities manifest in daily functioning has not been well established. To support clinical care of youth with ADHD, it is important to better understand the functional consequences and relevant outcomes associated with processing speed deficits. This systematic review and meta-analysis sought to identify the association between processing speed and clinical or functional correlates among children or adolescents diagnosed with ADHD. A total of 409 abstracts were screened, of which, 60 full-text articles were identified as potentially relevant, and 8 of these studies met inclusion criteria. Domains evaluated across these studies included reading skills, mathematics skills, written expression, anxiety, self-appraisals of competence, and adaptive functioning. Six studies reported an association between processing speed and reading skills, allowing for meta-analysis. Processing speed difficulties among youth with ADHD appear strongly associated with several clinical and functional correlates including weaker academic skills, poorer adaptive skills, increased self-reported anxiety, and overestimates of social competence. Meta-analytic results for studies reporting the association between processing speed and reading skills indicate a medium overall weighted mean effect size (r = 0.33, 95% CI = 0.28 –0.39) with minimal heterogeneity (I² = 0.17). Clinical implications of these findings, limitations in the current knowledge base, and suggestions for future research are discussed.     

Depression and Self-Esteem in Boys with Attention-Deficit/Hyperactivity Disorder: Associations with Comorbid Aggression and Explanatory Attributional Mechanisms

It was tested whether boys with attention-deficit/hyperactivity disorder (ADHD), subgrouped by aggressive status, would show higher rates of depressive symptomatology and lower levels of self-esteem than would comparison boys and, in a subsample, explored attributional mechanisms that may be related to such internalizing features. Study 1 utilized 114 boys with ADHD (all prior recipients of stimulant medication) and 87 comparison boys, aged 7–12 years. Aggressive boys with ADHD reported more symptoms of depression than did nonaggressive boys with ADHD, who, in turn, reported more depression than did comparison boys. Effect sizes were moderate to large and did not vary with a depression rating scale uncontaminated by ADHD-related items. For self-esteem, the most pronounced effect was that aggressive boys with ADHD showed lower levels than did nonaggressive ADHD or comparison boys; effects were again moderate to large. Study 2 participants were a subsample of boys with ADHD from Study 1 (N = 27). We probed causal attributions in ADHD-related domains through responses to hypothetical vignettes, in which the protagonist's medication status (medicated, not medicated) was crossed with type of outcome (good, bad). Medication-related attributions were frequent. In describing the protagonist's success in relation to medication treatment, the sample showed significant associations between (a) medication-related attributions and (b) increased depressive symptomatology as well as decreased self-esteem. We discuss attributional processes that may help to explain the variation in internalizing symptoms among children with ADHD.     

Hyperactivity in boys with attention deficit/hyperactivity disorder (ADHD): The association between deficient behavioral inhibition,attentional processes,and objectively measured activity

Contemporary models of ADHD hypothesize that hyperactivity reflects a byproduct of inhibition deficits. The current study investigated the relationship between children's motor activity and behavioral inhibition by experimentally manipulating demands placed on the limited-resource inhibition system. Twenty-two boys (ADHD = 11, TD = 11) between the ages of 8 and 12 years completed a conventional stop-signal task, two choice-task variants (no-tone, ignore-tone), and control tasks while their motor activity was measured objectively by actigraphs placed on their nondominant wrist and ankles. All children exhibited significantly higher activity rates under all three experimental tasks relative to control conditions, and children with ADHD moved significantly more than typically developing children across conditions. No differences in activity level were observed between the inhibition and noninhibition experimental tasks for either group, indicating that activity level was primarily associated with basic attentional rather than behavioral inhibition processes.     

Performance and Private Speech of Children with Attention-Deficit/Hyperactivity Disorder While Taking the Tower of Hanoi Test: Effects of Depth of Search,Diagnostic Subtype,and Methylphenidate

We administered the Tower of Hanoi to demographically comparable samples of control participants (n = 34) and children with the Combined (n = 22) and Inattentive subtypes (n = 19) of Attention-Deficit/Hyperactivity Disorder (ADHD). Controls excelled over children with the Inattentive subtype, who outperformed patients with the Combined subtype. These results replicated findings of greater executive deficits in the Combined than in the Inattentive type of ADHD. Double-blind administration of methylphenidate improved task performance only for patients with the Inattentive subtype. In a drug-free Baseline session, children with both subtypes of ADHD made more private verbalizations than controls, particularly when failing puzzles. In later sessions, regardless of drug condition, the inattentive sample exhibited a smaller increase in self-regulatory utterances under failure. In contrast, the combined sample decreased self-regulatory verbalizations under failure only under methylphenidate. The results support some differences between the two subtypes of ADHD in executive functioning and in their response to stimulant therapy. Portions of these results were submitted as part of H. Theresa Chang's PhD dissertation (Chang, 2000) and Helena Kopecky's unpublished master's research, both conducted at the University of Rochester and supervised by Rafael Klorman.     

Self-Handicapping Prior to Academic-Oriented Tasks in Children with Attention Deficit/Hyperactivity Disorder (ADHD): Medication Effects and Comparisons with Controls

Examined self-handicapping prior to academic-oriented tasks in children with and without ADHD and examined whether stimulant medication influenced self-handicapping. Participants were 61 children ages 6 to 13, including 22 children with ADHD tested after taking a placebo, 21 children with ADHD tested after taking stimulant medication, and 18 non-ADHD controls. Participants completed three measures of self handicapping and also completed self-evaluations of their performance. Results showed greater self handicapping and more positive self-evaluations in children with ADHD than in controls regardless of medication condition. Findings suggest children with ADHD may use self handicapping to ameliorate the effects of experiencing high rates of academic failure.     

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.     

Memory Functioning in Children with Reading Disabilities and/or Attention Deficit/Hyperactivity Disorder: A Clinical Investigation of their Working Memory and Long-Term Memory Functioning

We examined memory functioning in children with reading disabilities (RD), Attention deficit/hyperactivity disorder (ADHD), and RD/ADHD using a clinic sample with a clinical instrument: the Children's Memory Scale, enhancing its generalizability. Participants included 23 children with RD, 30 with ADHD, 30 with RD/ADHD, and 30 controls. Children with RD presented with reduced verbal short-term memory (STM) but intact visual STM, central executive (CE), and long-term memory (LTM) functioning. Their deficit in STM appeared specific to tasks requiring phonetic coding of material. Children with ADHD displayed intact CE and LTM functioning but reduced visual-spatial STM, especially when off stimulant medication. Children with RD/ADHD had deficits consistent with both disorders.     

The Test of Variables of Attention (TOVA): Internal Consistency (Q1 vs. Q2 and Q3 vs. Q4) in Children with Attention Deficit/Hyperactivity Disorder (ADHD)

The internal consistency of the Test of Variables of Attention (TOVA) was examined in a cohort of 6- to 12-year-old children (N = 63) strictly diagnosed with ADHD. The internal consistency of errors of omission (OMM), errors of commission (COM), response time (RT), and response time variability (RTV) of different test conditions (stimulus infrequent condition [Q₁ vs. Q₂] and stimulus frequent condition [Q₃ vs. Q₄]) was assessed via correlation analyses. All TOVA index scores under investigation assessing its internal consistency exhibited statistically significant correlations. All correlations fell in the moderate-high range.