Predictive validity of attentional functions in differentiating children with and without ADHD: a componential analysis

Aim The objective of this study was to investigate which attentional components are of predictive utility in differentiating children with attention‐deficit–hyperactivity disorder, combined type (ADHD‐C) from their peers without ADHD. Methods Thirty‐four children participated in the study: 17 males with ADHD‐C (mean age 10y 4mo, SD 1y 9mo) and 17 comparison children (12 males, 5 females; mean age 10y 8mo, SD 1.7y). Attentional functions were assessed using a computer‐administered, child‐friendly test series in German (i.e. Testbatterie zur Aufmerksamkeitsprüfung für Kinder; KITAP). The KITAP measures several attentional components, including alertness and executive attention (inhibition, divided attention, flexibility). Results The variable best able to discriminate between children with and without ADHD‐C was found to be response time variability in a go/no go task, followed by, in order, number of errors in a divided attention task and response time variability in an alertness task. However, group discrimination was not facilitated by differences in either response latency or accuracy of response in visuospatial attention and attentional flexibility tasks. Interpretation The assessment of attentional functions proved to be a powerful instrument for discriminating between children with and without ADHD‐C. Notably, the discriminative power of executive attention was found to be task dependent and dependent on processing demands.     

Differential effects of methylphenidate on attentional functions in children with attention-deficit/hyperactivity disorder

OBJECTIVE: To examine the effects of methylphenidate on different attentional functions and behavior in children with attention-deficit/hyperactivity disorder (ADHD). METHOD: A total of 60 ADHD children aged between 8 and 12 years completed a randomized, double-blind, placebo-controlled, within-subject crossover trial with two doses of methylphenidate (0.25 and 0.5 mg/kg body weight) and placebo. A comprehensive neuropsychological test battery was applied, including tests of alertness and sustained, focused, and divided attention as well as two executive tests, the stop-signal paradigm and a visual set-shifting task. RESULTS: A linear improvement was identified for both medication conditions in the alertness and focused and sustained attention task, but no significant improvement was found for divided attention. Quadratic trends were found for both executive tasks. Responders defined by behavior ratings did not differ from nonresponders. CONCLUSIONS: Results indicate that attentional functions are influenced differentially by methylphenidate: intensity-dimension functions are best influenced by higher doses, executive functions by moderate doses, and selectivity-dimension functions by variable doses. In addition, divergent results from behavior rating scales and from attentional paradigms emphasize that clinicians have to decide what constitutes an appropriate clinical response. A more comprehensive assessment of attention may help to find an individually optimal dose for the treatment of attentional dysfunctions.     

A novel multidomain computerized cognitive assessment for attention-deficit hyperactivity disorder: evidence for widespread and circumscribed cognitive deficits

Multidomain assessment may enhance the diagnosis of cognitive impairment in children with attention-deficit hyperactivity disorder (ADHD). A set of novel Web-enabled computerized tests has recently been shown to be valid for identifying mild cognitive impairment and characterizing the cognitive profile associated with various disorders. It was anticipated that these tests would be well suited for use in children with ADHD. The authors tested this idea in a pilot study of 15 children (12 males, 3 females; mean age, 11 years 10 months; range, 9-15 years) with ADHD and 15 age-, education-, and gender-matched controls. The profile of cognitive impairment in ADHD children off methylphenidate across 6 cognitive domains (memory, executive function, visual-spatial skills, verbal function, attention, and motor skills) was described relative to controls. The effect of treatment with methylphenidate was examined by comparing the ADHD children on methylphenidate and on placebo (administered in a double-blind randomized fashion) relative to controls and by comparing the ADHD children on methylphenidate relative to placebo. Significant impairment in ADHD was evident in memory, visual-spatial, verbal, and attention domains, and near-significant impairment was observed in executive function and motor skills. On methylphenidate but not placebo, performance was comparable to controls in immediate verbal memory, psychomotor accuracy, visual-spatial, verbal rhyming, and overall battery performance. Significant improvement with administration of methylphenidate relative to placebo was evident for psychomotor accuracy, verbal rhyming, and overall battery performance. Hence, on the limited basis of this pilot study, the set of computerized tests studied appears to be useful for measuring cognitive function in ADHD; however, additional studies are needed to confirm this.     

Treatment effects of methylphenidate on cognitive functioning in children with mental retardation and ADHD

OBJECTIVE: Cognitive effects of stimulant medication were investigated in children with mental retardation (MR) and attention-deficit/hyperactivity disorder (ADHD). METHOD: Performance on tasks tapping sustained attention, visual and auditory selective attention, inhibition, and immediate memory was assessed for 24 children (mean age 10.9 years) during a placebo-controlled, double-blind, crossover treatment trial with 0.15, 0.30, and 0.60 mg/kg b.i.d. dosages of methylphenidate (MPH). RESULTS: Successively higher MPH doses were associated with consistent gains in cognitive task performance, with optimal performance noted at the highest dose. Analysis of dose-response curves revealed significant linear components of trend on measures tapping sustained attention, visual selective attention, auditory selective attention, as well as two tasks tapping inhibition/impulsivity: delay of gratification and match-to-sample. No evidence of a curvilinear dose-response relationship emerged for any measure. CONCLUSIONS: Inattention and disinhibition/impulsivity decline with MPH treatment in children with ADHD/MR, and consistent with the Multimodal Treatment Study of ADHD, higher MPH doses are most effective. These findings also suggest that cognitive testing, together with behavioral and medical assessment, can be an effective tool in assessing stimulant response in children with ADHD/MR.     

Does attention‐deficit–hyperactivity disorder exacerbate executive dysfunction in children with neurofibromatosis type 1?

Aim Although approximately 40% of children with neurofibromatosis type 1 (NF1) meet diagnostic criteria for attention‐deficit–hyperactivity disorder (ADHD), the impact of ADHD on the executive functioning of children with NF1 is not understood. We investigated whether spatial working memory and response inhibition are impaired in children with NF1 without a diagnosis of ADHD and whether executive deficits are exacerbated in children with a comorbid diagnosis. Method Forty‐nine children aged 7 to 15 years with NF1 only (31 males, 18 females; mean age 11y, SD 2y 4mo) or 35 with NF1 and ADHD (18 males, 17 females; mean age 10y 8mo, SD 2y 4mo) and 30 typically developing comparison children (16 males, 14 females; mean age 10y, SD 2y 8mo) were compared on measures of spatial working memory and response inhibition. Group differences in IQ and visuospatial ability were controlled for as required. Results Compared with typically developing children, children with NF1 with or without comorbid ADHD demonstrated significant impairment of both spatial working memory (both p<0.004) and inhibitory control (both p<0.010). There were, however, no differences between the two NF1 groups in spatial working memory (p=0.91) or response inhibition (p=0.78). Interpretation Executive dysfunction occurs with the same severity in children with NF1, whether or not they have a comorbid diagnosis of ADHD, suggesting that executive impairments are not unique contributors to ADHD symptomatology in NF1. The findings are discussed within the context of recent evidence in Nf1 optic glioma (OPG) mice, in which a mechanistic connection between NF1 gene expression, executive system failure, and dopaminergic pathway integrity has been established.     

Components of Attention in Children with Complex Partial Seizures With and Without ADHD

Summary: Purpose: To evaluate attentional difficulties in children with complex partial seizures, we reviewed the records of 12 children with complex partial seizures with attention deficient hyperactivity disorder (CPS/ADHD); 21 children with CPS without ADHD (CPS); 22 children with ADHD; and 15 control children.
Methods: Each child completed a computerized performance test (CPT), which evaluated sustained attention, inhibition of response, response time, and consistency of response. The ADHD groups also completed the CPT after a dose of methylphenidate.
Results: The results found poorest performance on the CPT by the CPS/ADHD group. Particular difficulty in attention was found for children with epilepsy regardless of the ADHD diagnosis. When methylphenidate was administered to the ADHD groups, both groups improved in performance on the CPT.
Conclusions: Epilepsy may predispose children to attention problems that can significantly interfere with learning. Similar improvement for children with CPS/ADHD was found with methylphenidate compared with baseline as for children with ADHD but without CPS.     

Naturalistic exploration of the effect of osmotic release oral system-methylphenidate on remission rate and functional improvement in Taiwanese children with attention-deficit-hyperactivity disorder

Aim: To determine the differences in the remission rate, recovery rate, functional improvement, and treatment adherence related to treatment with short‐acting immediate‐release methylphenidate (IR‐MPH) and long‐acting osmotic‐release oral system‐methylphenidate (OROS‐MPH) in a naturalistic setting among Taiwanese children with attention‐deficit–hyperactivity disorder (ADHD). Methods: A total of 757 children with ADHD, aged 6–18 years, was evaluated using the following in order determine functional improvement and treatment adherence: the Chinese version of the Swanson, Nolan, and Pelham, version IV scale (SNAP‐IV‐C), Clinical Global Impression‐ADHD‐Severity (CGI‐S) to measure remission and recovery rates, the Chinese version of the Social Adjustment Inventory for Children and Adolescents (CSAICA), and caregiver's satisfaction rate, treatment adherence, and frequency of adverse effects. Results: According to the SNAP‐IV‐C scores, the remission rate was 30.72%, and the recovery rate was 16.38%. Compared to short‐acting IR‐MPH, OROS‐MPH was associated with greater functional improvement and treatment adherence among children with ADHD. Conclusion: OROS‐MPH treatment at the adequate dosage can achieve higher remission and recovery rates, produce greater functional improvement, and result in better treatment adherence than IR‐MPH treatment.     

Oculomotor abnormalities in attention deficit hyperactivity disorder: a preliminary study

BACKGROUND: Prevailing hypotheses suggest that attention deficit hyperactivity disorder (ADHD) is secondary to dysfunction of motor intentional systems mediated by prefrontal circuitry. Oculomotor paradigms provide a mechanism for examining and localizing dysfunction at the interface between movement and cognition. OBJECTIVE: Three different saccade tasks (reflexive or prosaccades, antisaccades, and memory-guided saccades) were used to examine functions necessary for the planning and the execution of eye movements, including motor response preparation, response inhibition, and working memory. METHODS: The study included 19 children with ADHD, divided into two groups: a group of 8 children on methylphenidate at the time of testing and a group of 11 children not taking any psychoactive medication. Results from the two groups were compared with those from 25 age- and gender-matched normal control children. RESULTS: Both groups of children with ADHD made significantly more directional errors than did controls on the antisaccade task and significantly more anticipatory errors than did controls on the memory-guided saccade task, findings that are consistent with deficits in response inhibition. There were no significant differences in prosaccade latency, although unmedicated children with ADHD showed significantly greater variability in latency on the prosaccade task than did controls. On the memory-guided saccade task there were no significant differences in saccade accuracy; however, unmedicated children with ADHD showed longer saccade latency than did either controls or medicated children with ADHD. CONCLUSIONS: Oculomotor findings suggest that deficits in prefrontal functions, in particular response inhibition, contribute to behavioral abnormalities observed in ADHD. Findings also suggest that the administration of methylphenidate is associated with improvements in the consistency of motor response. Although there were no observed improvements in response inhibition with methylphenidate, conclusions await a design in which subjects complete testing both on and off medication.     

Interaction of attention and graphomotor functions in children with attention deficit hyperactivity disorder

The present article provides a review of a series of studies in children with attention deficit hyperactivity disorder (ADHD) concerning (1) the effects of methylphenidate on various attentional functions, (2) the stimulant-induced changes of both qualitative and quantitative (i.e. kinematic) aspects of handwriting, (3) the interaction between conscious control of handwriting and fluency of handwriting movements, and (4) possible therapeutic approaches to graphomotor disturbances. Children with ADHD showed impairments in various aspects of attentional functioning. Pharmacological treatment of ADHD children with methylphenidate resulted in marked improvements of various components of attentional functioning. In comparison to the performance following the withdrawal of methylphenidate, children with ADHD on methylphenidate displayed a significant improvement in task accuracy in the areas of vigilance, divided attention, selective attention (inhibition, focused attention and integration of sensory information) and flexibility. However, the comparison with healthy children revealed considerable deficits regarding vigilance, divided attention, flexibility and selective attention (focused attention and integration of sensory information) in children with ADHD on methylphenidate. The comparison of writing movements of children on and off methylphenidate revealed that medication resulted in a better handwriting, but a deterioration in handwriting fluency as assessed by kinematic analysis. Children with ADHD may use their increased attentional capacities to focus on skills (e.g. handwriting) that are independent of conscious control or may even be disturbed by attention. The findings summarized in this paper indicate, therefore, that administration of methylphenidate alone is insufficient in the treatment of children with ADHD. Children with ADHD may benefit from instructions on how to best use their improved attentional capacities.     

Attention-deficit/hyperactivity disorder in childhood epilepsy: a neuropsychological and functional imaging study

Purpose: Children with epilepsy have a significant risk for attention‐deficit/hyperactivity disorder (ADHD), which is often accompanied by deficits in working memory performance. However, it is not yet clear whether there are specific differences in the underlying mechanisms of working memory capability between children with epilepsy‐related ADHD and those with developmental ADHD. There is evidence that methylphenidate can improve the behavioral difficulties in children with developmental ADHD. Whether this medication has the same effect on ADHD symptoms in patients with epilepsy is not yet well understood. The aim of the present study is, therefore, to evaluate whether boys with epilepsy‐related ADHD and developmental ADHD share a common behavioral, pharmacoresponsive, and neurofunctional pathophysiology. Methods: Seventeen boys with diagnosed combined epilepsy/ADHD, 15 boys with developmental ADHD, and 15 healthy controls (aged 8–14 years) performed on working memory tasks (N‐back) while brain activation was recorded using functional magnetic resonance imaging. Each patient was tested twice: once after the intake of methylphenidate and once without in a counterbalanced order. Key Findings: On a behavioral level, we show that boys with epilepsy‐related ADHD as well as those with developmental ADHD performed similarly poorly on tasks with high cognitive load when compared to healthy controls, and that intake of methylphenidate improved performance almost to normal levels in both ADHD groups. On the functional level, both patient groups showed similar reductions of activation in all relevant parts of the functional network of working memory when compared to controls. Of interest, intake of methylphenidate did not significantly alter this activity pattern. Significance: Our data show strong similarities between epilepsy‐related and developmental ADHD on the behavioral, pharmacoresponsive, and neural level, favoring the view that ADHD with and without epilepsy shares a common underlying neurobehavioral pathophysiology.     

Examining the link between working memory behaviour and academic attainment in children with ADHD

Aim The aim of the present study was to investigate whether behaviours typical of working memory problems are associated with poor academic attainment in those with attention‐deficit–hyperactivity disorder (ADHD), as well as a non‐clinical group identified on the basis of working memory difficulties. Method Children clinically diagnosed with ADHD‐combined (n=31; mean age 9y 7mo, SD 12mo; 27 males) were matched with 44 low working memory children (mean age 9y 4mo, SD 15mo; 32 males) and 10 healthy controls (mean age 10y, SD 12mo; 5 males). Working memory behaviour was measured using the Working Memory Rating Scale (WMRS) and academic attainment was assessed with standardized tests of literacy and numeracy. Results The majority of children considered by their teachers to have problematic behaviours performed poorly in literacy and numeracy. When the whole sample were split into two groups on the basis of their working memory behaviour (on the WMRS), the ‘At Risk’ group performed significantly worse in academic attainment. Interpretation As children with ADHD and a non‐clinical group exhibit classroom behaviour typical of working memory problems, early screening to prevent subsequent learning difficulties is important. The use of the WMRS allows educators to draw on their expertise in the classroom for early detection of children with working memory failures.     

Immediate effects of methylphenidate on cognitive attention skills of children with attention-deficit-hyperactivity disorder

This study investigated the immediate effects of stimulant medication (methylphenidate) on cognitive attention processes in children with attention-deficit-hyperactivity disorder (ADHD). Thirteen males and two females (mean age 9 y 5 mo, SD 18.3 mo) with a diagnosis of ADHD and who were to be prescribed methylphenidate were assessed twice on one day with the Test of Everyday Attention for Children, a neuropsychological battery designed to tap different aspects of cognitive attention. Between assessments, the children were administered methylphenidate (10 mg). Each child had at least average intelligence (IQ 80 or over, as measured by the Wechsler Intelligence Scale for Children-III UK) and was on no other medication. A group of 16 children, who were matched for age, sex, and intelligence, also performed the cognitive tests twice on the same day to control for practice effects of testing. At the first assessment, children with ADHD demonstrated significant impairments in several aspects of cognitive attention in comparison with the control group, particularly sustained attention. After administration of methylphenidate for the children with ADHD, they showed significant improvements in their performance on measures of cognitive attention compared to controls. The immediate effects of methylphenidate and the significance of measuring cognitive aspects of attention as well as behavioural measures are discussed.     

Is Response to OROS‐Methylphenidate Treatment Moderated by Treatment with Antidepressants or Psychiatric Comorbidity? A Secondary Analysis from a Large Randomized Double Blind Study of Adults with ADHD

Aims: The main aim of this post hoc analysis was to evaluate whether response to osmotic release oral system (OROS) methylphenidate (OROS‐MPH) was moderated by the concomitant use of antidepressants in attention‐deficit/hyperactivity disorder (ADHD) adults stabilized on these medicines for the treatment of depression or anxiety disorders, or a history of mood, anxiety, or substance use disorders. Methods: Two hundred and ninety‐six subjects were screened for participation; 227 were randomized (112 to OROS‐MPH and 115 to placebo), and 223 were analyzed (N= 109 and N= 114 for OROS‐MPH and placebo, respectively). Subjects with anxiety disorders and depression treated with a stable medication regimen of non‐MAOI antidepressants or benzodiazepines for at least 3 months could be enrolled in the study. Subjects currently receiving pharmacotherapy for anxiety disorders or depression were required to have Hamilton‐Depression and Hamilton‐Anxiety rating scales below 15 (mild range). Results: Concomitant antidepressant use at baseline was not associated with ADHD response, OROS‐MPH dose, study completion rate, adverse effects, or exacerbation of anxiety/depression. We did find nominally significant evidence that a lifetime history of mood (P= 0.09) or anxiety (P= 0.04) disorders was a moderator of ADHD symptoms and that a lifetime history of substance use disorder (P= 0.02) was a potential moderator of dose at endpoint. Discussion and Conclusions: We found few moderating effects in this large clinical trial of OROS‐MPH in adults with ADHD, which supports the robustness of the clinical response to OROS‐MPH in adult ADHD despite variable clinical pictures.     

The Diagnostic Utility of Executive Function Assessments in the Identification of ADHD in Children

Background:  Deficits in executive functions have been widely reported to characterise individuals with ADHD. The aim of this study was to evaluate the utility of a range of executive function measures for identifying children with ADHD.
Method:  Eighty-three children with ADHD and 50 normally-developing children without ADHD were assessed on measures of inhibition, set-shifting, planning, problem-solving, response inhibition, sustained attention and working memory. Measures of sensitivity, specificity, likelihood ratios and diagnostic odds ratios were calculated.
Results:  Executive function tasks effectively discriminated between children with and without ADHD. Measures of response inhibition and working memory contributed the most to the discriminant function.
Conclusions:  Cognitive measures of executive function can be used to help identify children with ADHD and could be useful as additional diagnostic tools for clinical practitioners.     

Acute effects of methylphenidate on impulsivity and attentional behavior among adolescents comorbid for ADHD and conduct disorder

Adolescents with Attention Deficit Hyperactivity Disorder (ADHD) and Conduct Disorder (CD) experience deficits in neuropsychological measures of attention, inhibition, and reward processes. Methylphenidate treatment for ADHD and CD has acute effects on these processes. Some of these same aspects of performance are separately described in the Behavioral Model of Impulsivity, which uses a modified approach to measurement. This study characterized the acute effects of methylphenidate attention, initiation, inhibition, and reward processes described in this model of impulsivity. Thirty-one adolescents from the United States of America with comorbid ADHD and CD completed measures of impulsivity (response initiation, response inhibition, and consequence) and attention following placebo, 20 mg, and 40 mg of a long-acting dose of methylphenidate. Methylphenidate effects on attentional performance was more robust than on any of the measures of impulsivity. Adolescent performance from this behavioral perspective is interpreted in the context of divergence from previous neuropsychological tests of acute methylphenidate effects.     

Cognitive effects of immediate-release methylphenidate in children with attention-deficit/hyperactivity disorder

A growing body of literature has examined the cognitive effects of immediate-release methylphenidate in children with attention-deficit/hyperactivity disorder (ADHD). However, a clear understanding of the types and magnitude of such effects are difficult to discern from such a large and varied collection of published reports. This review evaluated a total of 40 relevant placebo-controlled studies published since Rapport and Kelly's [1993. Psychostimulant effects on learning and cognitive function. In: Matson, J.L. (Ed.), Handbook of Hyperactivity in Children. Allyn & Bacon, Boston, pp. 97–136] original review of cognitive effects of methylphenidate in children with ADHD. Of these published studies, 63.5% identified some improvement in cognitive function following methylphenidate treatment. Methylphenidate improved performance on saccadic eye movement, planning/cognitive flexibility, attention/vigilance, and inhibitory control tasks in 83.3%, 71.4%, 70.6%, and 69.7% of studies, respectively. A total 58.3% and 50% of studies that evaluated the effect of methylphenidate on tasks of memory and working memory/divided attention, respectively, noted improvement. Variability of findings across studies may be explained by differential effects of methylphenidate on brain function, intra- and inter-individual variability in medication response, methodological limitations, and problems associated with repeated neuropsychological assessment and metric properties of commonly utilised neuropsychological instruments.     

Attention and executive functions profile in drug naive ADHD subtypes

Attention deficit hyperactivity disorder (ADHD) has been associated with executive functioning and sustained and divided attention deficits. In order to clarify the questions on neurocognitive impairment in ADHD, we investigated the presence of specific executive functions (EFs) and attention deficit patterns in ADHD clinical subtypes. 50 patients with ADHD and 44 controls were evaluated. All subjects were boys and performed a clinical-psychopathological and neuropsychological battery. Five main domains of EFs and attention were studied. Executive functions-related neurocognitive abilities were used as control tasks. ADHD patients, inattentive and combined subtypes differ from controls on response inhibition, divided attention, phonological, and visual object working memory and on variability of reaction times measured with CPT. Comparison of ADHD subtypes, in five main domains of EFs, did not show evidence of different executive functioning profiles. Response inhibition can predict performance on working memory tests but it cannot predict performance on divided attention/set shifting and on sustained attention. ADHD boys exhibit a selective impairment on executive functions and attention tasks. These data suggest the involvement of partially independent neural circuits which control inhibition and divided attention in ADHD. Since right prefrontal cortex seems to be crucial in controlling response inhibition, while left dorsolateral prefrontal cortex seems important in modulating divided attention, these areas are deputated to be involved in the pathogenesis of neuropsychological deficits in ADHD subtypes. In addition, this study candidates the impairment in phonological and visual-object working memory as a possible neuropsychological trait in ADHD males with inattentive or combined subtypes.     

Dose-related effect of methylphenidate on stopping and changing in children with attention-deficit/hyperactivity disorder

PURPOSE: The effect of methylphenidate (MPH) on inhibitory control as assessed by the stop task in children with attention-deficit/hyperactivity disorder (ADHD) could be influenced by task difficulty and may be mediated by attention. SUBJECTS AND METHODS: Fifteen children with ADHD performed the stop and the change task after placebo, 0.5 and 1.0 mg/kg MPH in a within-subject design. RESULTS: Linear-trend analysis showed a similar effect of MPH in both tasks and a stronger effect for inhibitory control than for attention. Furthermore, a correlation was found between blood serum metabolites of norepinephrine and dopamine for attentional measures and inhibitory control measures, respectively. DISCUSSION AND CONCLUSION: In children with ADHD MPH could act primarily on inhibitory control, and is not influenced by task difficulty. Also, attention and inhibitory control could have differential pharmacological profiles.     

Methylphenidate-induced improvements of various measures of attention in adults with Attention Deficit Hyperactivity Disorder

Summary. The present study examined the effect of the stimulant medication methylphenidate (MPH) on attentional functioning of adults with ADHD. Sixteen adults with a diagnosed ADHD without comorbidity were assessed twice, at baseline off MPH and following MPH treatment. The assessment battery consisted of reaction time tasks of low complexity, including measures of alertness – subdivided into tonic and phasic alertness, vigilance, divided attention, flexibility and such aspects of selective attention as including focused attention, inhibition and integration of sensory information. In addition, 16 healthy participants who were matched to adults with ADHD according to sex, age, education level and intellectual functions were also assessed twice using the same test battery. The results of the present study suggest that adults with ADHD off stimulant medication are seriously impaired in various components of attention including vigilance, divided attention, selective attention and flexibility. These impairments of attention were observed primarily in regard to reaction time and its variability. Treatment of adults with ADHD using individually tailored doses of MPH has a positive effect on measures of alertness, vigilance, selective attention, divided attention and flexibility. However, even on MPH adults with ADHD displayed considerable deficits in vigilance and integration of sensory information. The present findings indicate that adults with ADHD are not differentially impaired in attentional processes but may suffer from a more global deficit of attention. Although MPH treatment has been found to be effective in the treatment of the attention deficit of adults with ADHD, additional treatment appears to be necessary.