7-10岁学龄儿童ADHD筛查研究

用SDQ（家长版）对上海10所小学二至四年级学生进行测查,以探求被试的ADHD症状表现,锁定ADHD高风险儿童。结果：（1）男生ADHD得分偏高（p<.01）,但女生在红橙两个级别内的百分数均高于男生;（2）9岁被试的ADHD得分分布最分散,占男生ADHD红色级别的比例最大,在女生ADHD得分中均值最大;（3）红橙两个级别为高风险级别。结论：（1）9岁是ADHD症状表现最严重的年龄;（2）女生具有更高的ADHD风险;（3）ADHD高风险被试晒出率：男生14.4%,女生17.4%。     

Book Review

Performance-based measures and ratings of executive functions were examined in a sample of adolescents with attention deficit/hyperactivity disorder (ADHD) and comparison controls. Performance-based measures of executive function included inhibition, working memory, set shifting, and planning, and ratings of these same executive functions were completed by parents and teachers. Adolescents with ADHD demonstrated lower executive function performance than controls and displayed elevated ratings on the executive function ratings by parents and teachers. Significant associations were obtained between the performance-based measures and the parent and teacher ratings, but each measure was not uniquely associated with its respective scale on the rating scales. When performance-based measures and ratings were examined as predictors of ADHD status, the parent and teacher ratings entered as significant predictors of ADHD status. Further commonality analyses indicated that performance-based measures accounted for little unique variance in predicting ADHD status and also displayed little overlap with the behavioral ratings. These findings highlight the diagnostic utility of behavioral ratings of executive function in predicting ADHD status; however, behavioral ratings should not be assumed to be a proxy for performance on measures of executive function in clinical practice.     

Deficit in Response Inhibition in Children with Attention Deficit/Hyperactivity Disorder (ADHD): Impact of Motivation?

To date, neuropsychological and psycho-physiological studies have revealed inconsistent results regarding an executive or motivational deficit explaining the response inhibition deficit in children with attention deficit/hyperactivity disorder (ADHD). Research on differentiating neuropsychological processes in ADHD subtypes is still scarce. Therefore, the motivational impact on response inhibition among boys with ADHD was examined in this study. In the first study, 19 boys with ADHD-combined type (ADHD-C) and 19 age-matched healthy control subjects performed a modified Go/No-Go task with the following experimental conditions: neutral, auditory feedback, reward, response cost, and reward/response cost. Performance and physiological data (heart rate and skin conductance responses) were recorded. In a second study with the modified Go/No-Go task, data for six children with ADHD-C, six with ADHD-inattentive subtype (ADHD-I), and six healthy control subjects were compared. Neither of the two studies revealed group by condition interactions. In study 1, boys with ADHD-C generally made more commissions and omissions compared to the control group. However, feedback significantly improved the response inhibition in all children. The heart rate of all children was increased in the two conditions of reward and reward/response cost. Study 2 revealed that children with ADHD-I responded more slowly and showed increased reaction time variability compared to both other groups. The present study supports an executive rather than a motivational deficit in the response inhibition among children with ADHD-C, though further results also indicate the role of auditory feedback on response inhibition. Additionally, the findings support the differentiation of ADHD-C and ADHD-I, suggesting that ADHD-I children are characterized by a sluggish cognitive tempo.     

Processing Speed Weakness in Children and Adolescents with Non-Hyperactive but Inattentive ADHD (ADD)

DSM-IV-TR defines ADHD-Predominantly Inattentive as allowing up to five symptoms of hyperactivity/impulsivity, while theories of the inattentive type usually assume a group that is hypoactive and characterized by processing speed and cognitive interference deficits. In a community-recruited sample of 572 children and adolescents, a pure inattentive subtype of ADHD (ADD) was defined as those who met DSM-IV-TR criteria for ADHD-PI but had two or fewer hyperactive/impulsive symptoms. Processing and output speeds of those with ADD were compared to those identified with DSM-IV-TR ADHD combined type and non-ADHD controls. These results were then contrasted with those found when DSM-IV-TR defined ADHD-PI was compared with ADHD-C and controls. Processing and output speed were assessed with the Trailmaking A and B and the Stroop Naming Tests. Cognitive interference control was assessed with the interference score from the Stroop Task. Slower cognitive interference speed was found in the ADD vs. ADHD-C and controls comparisons, but not the ADHD-PI versus ADHD-C and controls comparisons. On output speed measures, ADD exhibited the slowest performance, significantly different from controls and the effect size for the set-shifting speed contrast (Trailmaking B) was double that of the ADHD-PI vs. control comparison. ADHD-Inattentive type as defined by the DSM-IV-TR is a heterogeneous condition with a meaningful proportion of those affected exhibiting virtually no hyperactive/impulsive symptoms. This subgroup may represent a distinct inattentive condition characterized by poor cognitive interference control and slow processing or output speed.     

Methylphenidate,Interstimulus Interval,and Reaction Time Performance of Children with Attention Deficit/Hyperactivity Disorder: A Pilot Study

Thirteen children with attention deficit/hyperactivity disorder (ADHD: DSM-IV-TR) participated in the pilot study. They carried out a Go/No-Go test with a short (2 seconds) and long (6 seconds) interstimulus interval (ISI) when on placebo and a therapeutic dose of methylphenidate (MPH). For the long-ISI placebo condition the responses were slow and inaccurate. This pattern of response may be due to underactivation of the readiness-to-respond state that is not fully controlled by effort allocation. Speed of response and accuracy were enhanced during the short-ISI placebo condition and the long-ISI MPH condition. However, the combined effect (short ISI and MPH) resulted in a fast but inaccurate response style. This pattern of response may be due to overactivation of the readiness-to-respond state. The data of the pilot study support the stimulus shift hypothesis: MPH administration result in deterioration on tests on which children had previously done well (short ISI plus placebo versus short ISI plus MPH). In addition, the data support the idea that ADHD is associated with poor state regulation rather than motivational (delay aversion) theories or temporal-processing/time-estimation theories of ADHD. The pilot study defined empirically an issue for further study with the larger controlled sample.     

Assessment of cognitive domains during treatment with OROS methylphenidate in adolescents with ADHD

Aim: To psychometrically assess cognitive domains in adolescents with ADHD during long-term open treatment with robust dosing of extended-release methylphenidate (OROS MPH).

Methods: Data were derived from a prospective clinical study of adolescent ADHD, employing the Cambridge Neuropsychological Test Automated Battery (CANTAB), before and after up to one year of treatment with OROS MPH. In the absence of placebo control, a similar age and gender group of youth without ADHD served as comparators.

Results: During the course of treatment with OROS MPH, ADHD youth’s performance significantly improved across multiple CANTAB tasks, including spatial working memory, rapid visual processing, verbal recognition memory, set shifting, and inhibition/vigilance. ADHD subjects’ scores in several CANTAB tasks, including spatial working memory, planning, and set shifting, were significantly more impaired at baseline compared to the non-ADHD comparison group; these significant differences were no longer seen at endpoint.

Conclusions: Statistically significant improvements in multiple cognitive domains were observed in a sample of adolescents with ADHD over the course of 12 months of robust treatment with extended-release methylphenidate. Rigorous, monitored stimulant treatment may be associated with objectively determined cognitive benefits; however, practice effects in this open trial cannot be ruled out. Further study on this important topic is warranted.     

Assessment of children's receptive vocabulary using event-related brain potentials: Development of a clinically valid test

The combined verbal and motor impairments characteristic of children with disorders such as Cerebral Palsy (CP) frequently compromise the accuracy of standard psychometric assessments. What is needed is a test to measure language that does not require verbal or motor responses. This study was designed to determine whether single-word receptive vocabulary could be assessed in young children without CP, using an ERP-compatible test based on Form M of the Peabody Picture Vocabulary Test-Revised (PPVT-R). Fifteen 10-year-old children with normal levels of psychometric intelligence participated. Ninety pictures were selected from the PPVT-R (Form M), representing three levels of single-word receptive vocabulary (Preschool, Child-Adolescent, Adult). Each picture was presented twice (pseudo-random), once paired with a spoken word that was semantically congruent with the picture and once paired with a semantically incongruent word. The children's N400 was significantly larger to incongruent than to congruent pairs, but only when the vocabulary was within their repertoire. The results are discussed in terms of electrophysiologic correlates of acquired language and the clinical use of this ERP test as an adjunct to assessing patients with moderate to severe communication and/or motor impairments (e.g., cerebral palsy, autism, head injury).     

MOTOR PREPARATION,MOTOR EXECUTION,ATTENTION, AND EXECUTIVE FUNCTIONS IN ATTENTION DEFICIT/HYPERACTIVITY DISORDER (ADHD)

Attention and executive functions were investigated in medicated and unmedicated children with ADHD combined type using a novel selective reaching task. This task involved responding as rapidly as possible to a target while at times having to ignore a distractor. Results indicated that unmedicated children with ADHD showed slow and inaccurate responding. Slow responding reflected problems at the stage of movement preparation but not movement execution. An attentional impairment, rather than a motor planning problem per se, appeared to underlie the slow movement preparation. Inaccurate responding reflected problems with response inhibition and selective attention, impulsivity, set-shifting, and difficulties in maintaining vigilance. Although medicated children with ADHD did not show slow movement preparation, they did show some response inaccuracy, resulting especially from impulsive responding.These findings suggest that ADHD is characterized by slow motor preparation (but not motor execution), and deficits in selective attention, vigilance, and executive functions. Preliminary results suggest that stimulant medication may resolve some of these motor, attentional and executive function deficits.     

Prenatal testosterone and preschool Disruptive Behavior Disorders

Disruptive Behavior Disorders (DBD), including Oppositional-Defiant Disorder (ODD) and Attention-Deficit/Hyperactivity Disorder (ADHD), are fairly common and highly impairing childhood behavior disorders that can be diagnosed as early as preschool. Prenatal exposure to testosterone may be particularly relevant to these early-emerging DBDs that exhibit a sex-biased prevalence rate favoring males. The current study examined associations between preschool DBD symptom domains and prenatal exposure to testosterone measured indirectly via right 2D:4D finger-length ratios. The study sample consisted of 109 preschool-age children between ages 3 and 6 (64% males; 72% with DBD) and their primary caregivers. Primary caregivers completed a semi-structured interview (i.e., Kiddie Disruptive Behavior Disorder Schedule), as well as symptom questionnaires (i.e., Disruptive Behavior Rating Scale, Peer Conflict Scale); teachers and/or daycare providers completed symptom questionnaires and children provided measures of prenatal testosterone exposure, measured indirectly via finger-length ratios (i.e., right 2D:4D). Study results indicated a significant association of high prenatal testosterone (i.e., smaller right 2D:4D) with high hyperactive–impulsive ADHD symptoms in girls but not boys, suggesting that the effect may be driven by, or might only exist in, girls. The present study suggests that prenatal exposure to testosterone may increase risk for early ADHD, particularly hyperactivity–impulsivity, in preschool girls.     

Emotional distraction in boys with ADHD: Neural and behavioral correlates

Although, in everyday life, patients with attention deficit hyperactivity disorder (ADHD) are frequently distracted by goal-irrelevant affective stimuli, little is known about the neural and behavioral substrates underlying this emotional distractibility. Because some of the most important brain responses associated with the sudden onset of an emotional distracter are characterized by their early latency onset and short duration, we addressed this issue by using a temporally agile neural signal capable of detecting and distinguishing them. Specifically, scalp event-related potentials (ERPs) were recorded while 20 boys with ADHD combined type and 20 healthy comparison subjects performed a digit categorization task during the presentation of three types of irrelevant, distracting stimuli: arousing negative (A−), neutral (N) and arousing positive (A+). Behavioral data showed that emotional distracters (both A− and A+) were associated with longer reaction times than neutral ones in the ADHD group, whereas no differences were found in the control group. ERP data revealed that, compared with control subjects, boys with ADHD showed larger anterior N2 amplitudes for emotional than for neutral distracters. Furthermore, regression analyses between ERP data and subjects’ emotional ratings of distracting stimuli showed that only in the ADHD group, emotional arousal (ranging from calming to arousing) was associated with anterior N2: its amplitude increased as the arousal content of the visual distracter increased. These results suggest that boys with ADHD are more vulnerable to the distracting effects of irrelevant emotional stimuli than control subjects. The present study provides first data on the neural substrates underlying emotional distractibility in ADHD.