Time perception and reproduction in young adults with attention deficit hyperactivity disorder

Adults with attention deficit hyperactivity disorder (ADHD; n = 104) were compared with a control group (n = 64) on time estimation and reproduction tasks. Results were unaffected by ADHD subtype or gender. The ADHD group provided larger time estimations than the control group, particularly at long intervals. This became nonsignificant after controlling for IQ. The ADHD group made shorter reproductions than did the control group (15- and 60-s intervals) and greater reproduction errors (12-, 45-, 60-s durations). These differences remained after controlling for IQ and comorbid oppositional defiant disorder, depression, and anxiety. Only the level of anxiety contributed to errors (at 12-s duration) beyond the level of ADHD. Results extended findings on time perception in ADHD children to adults and ruled out comorbidity as the basis of the errors.     

Personality assessment of children with attention deficit hyperactivity disorder

The present research was designed to assess several potentially important factors in the personality structure of a sample of children with attention deficit hyperactive disorder (ADHD) as compared to normal control children. Three questionnaires were administered to a group of 28 ADHD boys and to a control group of 83 boys: (1) The Locus of Control Scale for Children; (2) The Revised Children's Manifest Anxiety Scale; and (3) The Persistence Scale for Children. Results showed that the ADHD children had significantly higher external locus of control, were significantly less persistent, and reported an elevated level of “concentration/social worry” (an anxiety subscale). Such findings can help to clarify both the personality structure and the coping styles of the ADHD child.     

Inhibition of return in children with attention deficit hyperactivity disorder

Earlier studies have suggested an impairment in the attention and eye movement control of children with ADHD. An important phenomenon in the control of attentional shifts and eye movements is the inhibition of return (IOR), which states that our brain works in a way that prevents our attention from returning to a spatial location that has been attended to, either overtly or covertly. This current study addresses whether the IOR in oculomotor planning is compromised in children with ADHD. Eleven ADHD and 12 age- and gender-matched control subjects participated in a behavioral task, in which they made saccades to a peripheral target after a valid, invalid or neutral cue. The latency difference between cued and uncued saccades over a range of cue-target onset asynchrony as well as the positive component of this latency profile (i.e., IOR) was compared between groups. The results show that ADHD children demonstrate a biphasic latency profile that is grossly similar to that observed in control subjects, although the magnitude of IOR appears to be slightly smaller in ADHD subjects. These preliminary results suggest that the inhibitory attention mechanism subserving IOR is at least not fully compromised in ADHD children. Electronic Publication     

Neuropsychological performance deficits in adults with attention deficit/hyperactivity disorder.

Neuropsychological deficits in children diagnosed with attention deficit/hyperactivity disorder (ADHD) have been well documented utilizing various neuropsychological tests. Only recently has research begun to examine if similar deficits are present in adults with ADHD. A neuropsychological testing battery was constructed that assessed verbal learning and memory, psychomotor speed, and sustained attention--all demonstrated to be deficient in individuals with ADHD. Fifty-six self-referred nonmedicated adults with a DSM-IV diagnosis of ADHD and 38 normal comparison adults participated. ADHD adults demonstrated verbal and nonverbal memory deficits and decreased psychomotor speed compared to normal controls. Differences between ADHD and normal adults were not documented on traditional measures of executive functioning. A pattern of results emerged whereby ADHD adults' performance, particularly with regard to psychomotor speed, became more impaired as task complexity increased. This study's results largely corroborate similar neuropsychological testing results in ADHD children and recent ADHD adult findings, and support a frontal lobe dysfunction hypothesis of ADHD.     

注意缺陷多动障碍儿童的工作记忆损害特征

目的:探讨注意缺陷多动障碍(ADHD)儿童工作记忆功能特征。方法:本研究为横断面研究。根据美国精神疾病诊断和统计手册第4版(DSM-IV),对符合ADHD诊断标准的未经治疗的100名门诊患儿及年龄、性别相匹配的100名正常儿童分别采用韦氏儿童智力测验量表中国修订本(C-WISC)及其中的顺背数字(反映言语存贮、加工)、倒背数字(反映言语存贮、加工、中央执行)、Corsi木块和空间n-Back任务(反映视空间存贮和中央执行)进行言语及空间工作记忆测试。结果:ADHD组儿童在顺背数字最高位数及总得分、倒背数字最高位数及总得分、Corsi木块最多木块数及总得分均低于对照组儿童,空间2-Back任务反应时短于对照组儿童(均P0.05)。结论:ADHD儿童存在工作记忆功能缺陷,此缺陷涉及言语环路、视空间存贮系统及中央执行。     

Mean platelet volume in children with attention deficit hyperactivity disorder

The mean platelet volume (MPV), the accurate measure of platelet size, is considered a marker and determinant of platelet function. MPV can be a potentially useful prognostic biomarker in patients with cardiovascular disease. After reviewing literature, we hypothesized that attention deficit hyperactivity disorder (ADHD) in childhood may be a risk factor for coronary heart disease (CHD) in adulthood. The aim of this study was investigation of MPV and platelet count (PLT) in children with ADHD and healthy subjects. The MPV and the PLT were measured in 70 children with ADHD (aged 6–16 years), and compared with 41 healthy controls. The MPV was found to be significantly increased in ADHD group compared to control group (p = .006). There was no significant difference in the PLT between groups (p > .05). To our knowledge, this was the first study of investigating the levels of MPV and PLT in children with ADHD. Although significance and cause of increased MPV level in ADHD remain unclear in present study, further studies are warranted to investigate relationships among MPV, ADHD in childhood and CHD in adulthood.     

Executive function profile of children with attention deficit hyperactivity disorder

We explored the neuropsychological profile for executive functions of children with attention deficit hyperactivity disorder (ADHD) to assess whether problems associated with the two most cited relevant processes-inhibition and attentional problems-were the core of any executive function difficulty. A battery of executive function tests was administered to 31 children with a clinical diagnosis of ADHD and to 33 normal control participants, all aged between 7 and 12. The executive function battery encompassed a number of tasks, selected because each had multiple measures: a sustained attention reaction time task, a related vigilance task, an adaptation of the Hayling Sentence Completion Test, an adaptation of the Brixton Spatial Rule Attainment Test, a Letter Fluency task, a number Stroop task, and an “n-back” working memory task. The overall pattern of the results fit well with those obtained in previous studies as far as abnormalities of the ADHD group in the domain of inhibitory processes, attentional functions, and executive functions. The children with ADHD, although performing well on baseline tasks, performed more poorly than the controls on all the experimental tasks with one borderline exception: Letter Fluency, where the children with ADHD showed a very different pattern than most adult frontal lobe subgroups. However, there was no specific impairment on measures of inhibitory processes. In addition, strategy generation and use were severely affected in the ADHD group. Particular findings fitted well with disorders of a high-level effort system and of a monitoring system.     

Evidence-based assessment of attention deficit hyperactivity disorder in children and adolescents.

This article examines evidence-based assessment practices for attention deficit hyperactivity disorder (ADHD). The nature, symptoms, associated features, and comorbidity of ADHD are briefly described, followed by a selective review of the literature on the reliability and validity of ADHD assessment methods. It is concluded that symptom rating scales based on the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Association, 1994), empirically and rationally derived ADHD rating scales, structured interviews, global impairment measures, and behavioral observations are evidence-based ADHD assessment methods. The most efficient assessment method is obtaining information through parent and teacher rating scales; both parent and teacher ratings are needed for clinical purposes. Brief, non-DSM based rating scales are highly correlated with DSM scales but are much more efficient and just as effective at diagnosing ADHD. No incremental validity or utility is conferred by structured interviews when parent and teacher ratings are utilized. Observational procedures are empirically valid but not practical for clinical use. However, individualized assessments of specific target behaviors approximate observations and have both validity and treatment utility. Measures of impairment that report functioning in key domains (peer, family, school) as well as globally have more treatment utility than nonspecific global measures of impairment. DSM diagnosis per se has not been demonstrated to have treatment utility, so the diagnostic phase of assessment should be completed with minimal time and expense so that resources can be focused on other aspects of assessment, particularly treatment planning. We argue that the main focus of assessment should be on target behavior selection, contextual factors, functional analyses, treatment planning, and outcome monitoring.     

Methylenetetrahydrofolate reductase gene polymorphisms in children with attention deficit hyperactivity disorder

Objective: The purpose of this study was to evaluate the relationship between 5,10- methylenetetrahydrofolate reductase (MTHFR) polymorphisms and Attention Deficit Hyperactivity Disorder (ADHD) in a sample of Turkish children.Study Design: MTHFR gene polymorphisms were assessed in 40 patients with ADHD and 30 healty controls. Two mutations in the MTHFR gene were investigated using polymerase chain reactions and restriction fragment length polymorphisms.Results: Although there were no statistically significant differences in genotype distributions of the C677T alleles between the ADHD and the control groups (p=0,678) but the genotypic pattern of the distributions of the A1298C alleles was different between the ADHD patients and the controls (p=0,033).Conclusions: Preliminary data imply a possible relationship between A1298C MTHFR polymorphisms and the ADHD.     

Sleep disorders in Taiwanese children with attention deficit/hyperactivity disorder

To assess obstructive sleep apnea syndrome (OSAS) and periodic limb movement disorder (PLMD) in children with attention deficit/hyperactivity disorder (ADHD) compared with a control group. The ADHD was diagnosed based on Diagnostic and Statistical Manual, version IV (DSM-IV) criteria on successively seen elementary school children aged 6-12 years referred to a psychiatric clinic for suspected ADHD. A standardized interview (Kiddie-SADS-E), parents and teacher questionnaires, neuropsychological testing, and nocturnal polysomnography were completed for each child. Eighty-eight children (77 boys) with ADHD and 27 controls were involved in the study. Fifty children with ADHD (56.8%) had an apnea-hypopnea index (AHI) >1 event h(-1) and 17 (19.3%) had an AHI >5 event h(-1). Nine children (10.2%) had a periodic limb movement index (PLMI) >5 events h(-1). There is one child with AHI >1 and none with a PLMI > 5 in the control group. In the test of variables of attention (TOVA), the response time was significantly worse in ADHD with sleep disorders than those without them. The child behavior checklist (CBCL) showed a significant difference between groups in the hyperactivity subscale. The diagnostic criteria for ADHD based on DSM-IV do not differentiate between children with or without sleep disorders. Evaluation of sleep disorders should be considered before starting drug treatment for ADHD.     

Effects of methylphenidate on aggressive urban children with attention deficit hyperactivity disorder

Determined the efficacy of methylphenidate (MPH) in a clinical population of aggressive, urban children diagnosed with attention deficit hyperactivity disorder (ADHD). In previous studies of prepubertal children with ADHD, MPH has been shown to be effective when compared with placebo. Eighteen inner-city children (ages 6 to 12 years), diagnosed with ADHD and attending a summer treatment program for youth with disruptive behavior disorders, participated in a double-blind placebo trial with assessment data obtained from staff in the program and parents at home. Based on staff ratings of the children's behavior in the program and an academic classroom, the children displayed significant improvements in ADHD symptoms and aggressive behavior with low- and high-dose MPH conditions. At home, parents and guardians reported few significant differences between placebo and MPH on behavior ratings. In both settings, MPH was well tolerated with few side effects found during active drug conditions.     

Mindfulness and attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a disorder characterized by attentional difficulties. Mindfulness is a receptive attention to present experience. Both ADHD and mindfulness are associated with attention and personality. This study tests whether individuals with ADHD have lower mindfulness scores than controls and, if true, whether personality contributes to these differences. One hundred and five adults (half with ADHD) were assessed for mindfulness, using the Kentucky Inventory of Mindfulness Skills, and personality, using the Tridimensional Character Inventory. Individuals with ADHD report themselves as less mindful than non‐ADHD controls and more novelty‐seeking, less self‐directed, and more self‐transcendent. Mindfulness is negatively associated with ADHD and positively associated with self‐directedness and self‐transcendence. Analyses of subscales of mindfulness suggest that ADHD is associated most with the “Acting in Awareness” dimension, perhaps because of shared items reflecting attentional variability. The current findings support that a large portion of variability in trait mindfulness can be explained by ADHD status and personality traits of self‐directedness and self‐transcendence. It further suggests that interventions that increase mindfulness might improve symptoms of ADHD and increase self‐directedness and/or self‐transcendence. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65: 1–12, 2009.     

Contextual abnormalities of saccadic inhibition in children with attention deficit hyperactivity disorder

Abnormalities of executive function are observed consistently in children with attention-deficit hyperactivity disorder (ADHD), and it is hypothesised that these arise because of disruption to a behavioural inhibition system. Executive and inhibitory functions were compared between unmedicated and medicated children with ADHD (combined type), age-matched healthy children and healthy adults. Executive functions were measured using a test of spatial working memory shown previously to be sensitive to ADHD and to stimulant medication. Inhibitory functions were measured using an ocular motor paradigm that required individuals to use task context to control the release of fixation. Context was set according to the probability that a target would appear at either of the two locations. In one block, targets appeared on 80% of trials. In the other block, targets appeared on 20% of trials. The ability to control the release of fixation was inferred from the fixation offset effect (FOE), or the difference in saccade latency when the current fixation is offset 200 ms prior to the onset of the saccade target (gap condition), compared with when there is no offset (overlap condition). Although the healthy children made more errors on the spatial working memory task than the healthy adults, there was no difference between the two groups in their ability to control fixation using context. Both showed a larger FOE when target probability was low. As expected, the unmedicated ADHD group made more errors on the spatial working memory test than the healthy children, although spatial working memory performance was normal in the medicated ADHD group. However, both the unmedicated and medicated ADHD groups were unable to modulate the FOE according to context, and this was due to their inability to voluntarily inhibit saccades when there was a low target probability. These data suggest that the context-based modulation of fixation release is not controlled by the same systems that control executive function. Furthermore, deficits in executive function and inhibitory control appear independent in children with ADHD.     

注意缺陷多动障碍儿童的眼动抑制缺陷对照研究

目的:探讨注意缺陷多动障碍(Attention Deficit Hyperactivity Disorder,ADHD)儿童在抑制性眼动任务中的反应特征。方法:采用注视、主动眼动及反向眼动任务对21例ADHD儿童和21例正常对照儿童进行评估。结果:(1)注视任务中,ADHD组侵入性眼跳数目高于对照组[无分心条件:(12.67±12.28)vs.(6.38±6.95),P=0.040;分心条件:(16.91±10.00)vs.(11.29±5.99),P=0.030];(2)主动眼动任务中,两组儿童眼跳参数差异无统计学意义;(3)反向眼动任务中,ADHD组眼跳方向错误率高于对照组[间隔条件:(68.14±17.85)%vs.(54.10±20.22)%,P=0.020;重叠条件:(62.49±17.54)%vs.(49.27±17.21)%,P=0.020]。结论:注意缺陷多动障碍儿童眼动抑制能力存在缺陷,推测可能是由于注意缺陷多动障碍儿童具有异常的额叶-纹状体结构和/或功能所致。     

Diversity and attention deficit hyperactivity disorder

Attention Deficit Hyperactivity Disorder (ADHD) is a debilitating disorder which affects children and adults in this country and around the world. Diversity variables such as ethnicity, age, gender, and socioeconomic status have been relatively neglected in ADHD research. Additionally, these variables have not traditionally been incorporated into clinical assessment, diagnosis, or intervention strategies. A review of the existing literature regarding diversity issues and ADHD was conducted, including a review of international findings. Implications for clinicians and researchers are incorporated. © 1998 John Wiley & Sons, Inc. J Clin Psychol 54: 415–426, 1998.     

注意缺陷多动障碍儿童的脑功能磁共振成像研究

【摘要】目的对正常儿童和注意缺陷多动障碍（ADHD））L童进行对比研究,观察2者的脑功能结构是否有生理性差异,从而加深对注意缺陷多动障碍病理机制的理解与认识,为诊断和治疗提供可靠的依据。方法利用脑功能磁共振成像（fiR[）技术,对2组儿童进行数据采集（一组为正常儿童,一组为注意缺陷多动障碍患者）,每组各5名;并对采集的数据分别用独立成分分析和统计参数映射技术进行处理分析,以研究这2种方法在处理数据过程中的优劣和差异。结果2种方法虽分别从数据和模型化2个不同方面对数据进行处理,各有优缺点,但都显示出ADHD患者与正常组被试的大脑激活区域的明显差异。ADHD患者的小脑扁桃体激活区增强,前额叶系统功能激活区减弱。结论通过不同方法对比fMRI结果各组之间的差异,进一步验证了ADHD患者的反应抑制缺陷。     

Impaired and enhanced attentional function in children with attention deficit/hyperactivity disorder

BACKGROUND: The symptom domain of inattention in attention deficit/hyperactivity disorder (ADHD) suggests that there are neuropsychological fields of attention in which subjects with ADHD express deficits. However, studies using differentiated neuropsychological attentional tests in ADHD are lacking. METHOD: A consecutive series of 35 subjects with ADHD aged 9-12 years were assessed on a computer-driven neuropsychological test battery for attentional functions. Their performance was classified according to the data of a normative sample of 187 healthy subjects aged 9-12 years, and compared with the performance of 35 matched healthy control subjects. RESULTS: According to normative data, most ADHD subjects performed on all attentional measures within the normal range. Comparisons with the control group revealed that ADHD subjects reacted faster on all attentional tests, yielding statistical significance for the Go/No go test and the Divided Attention test. They also performed with significantly fewer errors on the Divided Attention test. On the Go/No go test, Visual Scanning test and Attentional Shift test ADHD subjects committed significantly more errors than control subjects. CONCLUSIONS: Our results suggest a differential pattern rather than a deficit pattern of attentional functions in ADHD. It is suggested that the more rapid response style of ADHD subjects leads to a more erroneous performance in self-paced attentional tasks and to a better performance in externally paced attentional tasks. However, neuropsychological tests of attention do not contribute to the clinical diagnosis of ADHD.