Developing ADHD

Over the past 50 years the concept of attention deficit/hyperactivity disorder (ADHD) has developed from the notion of a specific form of brain dysfunction to that of a heterogeneous set of related behaviours. The great advances in genetics, neuroimaging and neuropsychiatry have made it one of the best understood forms of complex mental disturbance – but much remains to be done to translate understanding into practice. More effective treatment may come from identifying and treating more specific components of disorder and by a focus on identifying the factors determining course in the longer term so that they, as well as the core features of disorder, can become targets for intervention.     

Managing ADHD

Medication can help, but a multimodal approach that also includes educational and psychological services works best for most children. Second of two parts.     

Colour perception in ADHD

Attention-deficit/hyperactivity disorder (ADHD) is associated with unexplained impairments on speeded naming of coloured stimuli. These deficits may reflect hypofunctioning retinal dopaminergic mechanisms impairing particularly blue-yellow colour discrimination. Colour perception and rapid colour naming ability were investigated in 14 children with ADHD and 13 healthy peers matched for age, gender, and IQ, using the Farnsworth-Munsell 100 Hue Test (FMT) and the Stroop-Colour-Word test. Children with ADHD committed more errors on the FMT, particularly on discrimination of colours along the blue-yellow axis, and were slower on Stroop subtests involving colour naming. However, the latter deficit was accounted for similarly by blue-yellow and red-green discrimination abilities. Blue-yellow colour perception problems in ADHD contribute to but do not fully explain the observed slowed colour naming.     

Differences between preschool children with ODD, ADHD, and ODD+ADHD symptoms

BACKGROUND: This study examines differences between children (ages 3 to 6 years) who have the symptoms of oppositional defiant disorder (ODD) with or without attention-deficit/hyperactivity disorder (ADHD), ADHD alone, and a nonODD/ADHD comparison group. Parent (N=595) and teacher (N=538) ratings were obtained for children attending the same community early childhood programs and for youngsters evaluated in an outpatient clinic (N=224) using a DSM-IV-referenced rating scale. RESULTS: Differences between symptom groups varied depending on how they were configured (teacher versus parent ratings) and setting (clinic versus community). In general, the ODD+ADHD group received the highest (and the comparison group the lowest) ratings of severity for the symptoms of other disorders, difficulties with peers, and developmental deficits. Moreover, the clinical impact of comorbidity was largely additive. Differences between youngsters with ODD versus ADHD symptoms were most apparent for teacher-defined groups in the community sample and parent-defined groups in the clinic sample. CONCLUSIONS: Collectively, these findings provide preliminary evidence for the notion that ODD and ADHD may constitute distinct clinical entities in preschool-aged children and suggest that informant may be an important consideration in the formulation of diagnostic criteria.     

Auditory conflict processing in ADHD

Background: Impaired cognitive control has been implicated as an important developmental pathway to attention deficit/hyperactivity disorder (ADHD). Cognitive control is crucial to suppress interference resulting from conflicting information and can be measured by Stroop‐like tasks. This study was conducted to gain insight into conflict processing in children with ADHD. Methods: Event‐related potentials (ERPs) were recorded in an auditory Stroop task. Twenty‐four children with ADHD were compared with 24 control children (aged 8–12 years). Results: No deficit in interference control was found on the auditory Stroop task in children with ADHD. Children with ADHD responded more slowly, less accurately and more variably compared to controls. No differences between the groups occurred in the early conflict‐related ERPs. However, the difference between the congruent and the incongruent condition in the 450–550 ms time window was absent in the ADHD group compared to controls. In addition, the conflict sustained potential was found frontally in the ADHD group but parietally in the control group. Conclusions: These ERP findings suggest that children with ADHD evaluate conflict to a lesser extent and differ in the way their brains select appropriate responses during conflict compared with controls.     

Self-induced overdose of ADHD medication

Abstract: Attention deficit hyperactivity disorder is a diagnosis made with increasing frequency and problems related to its drug management are also beginning to appear with increasing frequency.     

注意缺陷障碍的临床研究

目的　探讨注意缺陷障碍 (ADHD)儿童的诊断、分型和性别差异。方法　根据DSM IV诊断标准 ,对2 0 0 3年 10月至 2 0 0 4年 3月因多动、注意力不集中、成绩下降而就诊上海儿童医学中心儿保门诊的 2 32例儿童进行诊断和分型 ;应用韦氏智力量表对诊断为ADHD儿童进行智力测试 ,比较男女儿童在智力结构及核心症状发生率的差异 ,并对核心症状进行聚类分析。结果　确诊为ADHD者 118例 ,女性儿童算术、拼图量表分明显落后于男性儿童 ,且语言智商、操作智商、总智商也低于男性儿童 (P <0 0 5 ) ;ADHD亚型中 ,以注意缺陷型为最多 ,其次为混合型 ,共 4 1例 ,多动冲动型最少 ,3个亚型中 ,男女发生率无性别差异 ;ADHD儿童核心症状的聚类分析结果有 4类 ;ADHD和非ADHD儿童不同性别核心症状的比较显示 :女性ADHD和非ADHD儿童之间的差异没有男性明显。结论　因多动、注意问题就诊的儿童中一半为ADHD ,其分型无性别差异。ADHD女性儿童智力明显落后于男性儿童。ADHD核心症状聚类分析有 4类。女性ADHD ,尤其多动冲动型的诊断过程中需考虑我国的文化差异。     

The neurobiological basis of ADHD

Attention-Deficit/Hyperactivity Disorder is not a single pathophysiological entity and appears to have a complex etiology. There are multiple genetic and environmental risk factors with small individual effect that act in concert to create a spectrum of neurobiological liability. Structural imaging studies show that brains of children with Attention-Deficit/Hyperactivity Disorder are significantly smaller than unaffected controls. The prefrontal cortex, basal ganglia and cerebellum are differentially affected and evidence indicating reduced connectivity in white matter tracts in key brain areas is emerging. Genetic, pharmacological, imaging, and animal models highlight the important role of dopamine dysregulation in the neurobiology of Attention-Deficit/Hyperactivity Disorder. To date, stimulants are the most effective psychopharmacological treatments available for Attention-Deficit/Hyperactivity Disorder. Currently only immediate release methylphenidate and atomoxetine are approved for the treatment of ADHD in Italy. Drug treatment should always be part of a comprehensive plan that includes psychosocial, behavioural and educational advice and interventions.     

注意力缺陷多动障碍儿童定量脑电图研究

目的探讨注意力缺陷多动障碍(ADHD)汉族男童的脑电图特征。方法对70例ADHD汉族男童(包括混合型64例,注意缺陷为主型6例)及30例年龄匹配的健康汉族男童进行定量脑电图功率谱分析。记录安静闭目状态下的脑电图,经傅里叶转换得到总功率,α、β、θ、δ频段绝对及相对功率,以及θ/α、θ/β等。结果 ADHD组较正常对照组δ活动增多,β活动减少,前脑区的总功率及θ/β升高。两亚型相比,混合型较注意缺陷为主型θ、δ活动增多,β活动减少,总功率、θ/α、θ/β升高。不同程度注意力缺陷患儿相比,重度组较轻中度组α活动减少,δ活动增多,θ/α升高。结论 ADHD汉族男童的脑电图与正常对照组显著不同。定量脑电图功率谱分析对ADHD诊断、亚型区分及病情评估具有一定的鉴别作用,在ADHD研究与临床领域具有良好的应用前景。