Detecting Attention Deficit Hyperactivity Disorder in a communications clinic: diagnostic utility of the Gordon Diagnostic System

Spontaneously hypertensive rats manifest deficits in emotional response to 22-kHz and 50-kHz ultrasonic playback

Many symptoms used routinely for human psychiatric diagnosis cannot be directly observed in animals which cannot describe their internal states. However, the ultrasonic vocalizations (USV) rodents use to communicate their emotional states can be measured. USV have therefore become a particularly useful tool in brain disease models. Spontaneously hypertensive rats (SHR) are considered an animal model of attention deficit hyperactivity disorder (ADHD) and schizophrenia. However, the specifics of SHR's behavior have not been fully described and there is very little data on their USV. Recently, we developed a communication model, in which Wistar rats are exposed to pre-recorded playbacks of aversive (22-kHz) or appetitive (50-kHz) USV, and their vocal responses depend on the extent of prior fear conditioning (0, 1, 6 or 10 shocks). Here, we investigated SHR's behavior and heart rate (HR) in our communication model, in comparison to Wistar rats employed as controls. In general, SHR emitted typical USV categories, however, they contained more short 22-kHz and less 50-kHz USV overall. Moreover, fewer SHR, in comparison with Wistar rats, emitted long 22-kHz USV after fear conditioning. SHR did not show a 50-kHz playback-induced HR increase, while they showed a profound 22-kHz playback-induced HR decrease. Finally, the number of previously delivered conditioning shocks appeared to have no effect on the investigated vocal, locomotor and HR responses of SHR. The phenomena observed in SHR are potentially attributable to deficits in emotional perception and processing. A lower number of 50-kHz USV emitted by SHR may reflect observations of speech impairments in human patients and further supports the usefulness of SHR to model ADHD and schizophrenia.

Transcranial Direct Current Stimulation (tDCS) in children with ADHD: A randomized, sham-controlled pilot study

BACKGROUND

ADHD is a common neurodevelopmental disorder with a pediatric prevalence of 5.2%.While medication treatment for ADHD is effective, it does not address all symptoms and a small but notable subgroup does not respond to medications. Adverse effects limit its use and some parents and participants resist use of medication. Thus, limitations of medication treatment for ADHD motivate searching for other therapeutic options. Transcranial Direct Current Stimulation (tDCS) has been suggested as a treatment for children with ADHD, with mixed results to date. Protocol variables employed, including combined use of cognitive training (CT) and scheduling of sessions, may explain diverse findings to date. The aim of this study was to examine safety, feasibility and efficacy of tDCS combined with CT provided three-times-per week for one-month to treat children with ADHD.

METHODS

In a double blind, randomized, sham-controlled pilot study, 25 children with ADHD were randomized to receive 12 sessions of either anodal tDCS or sham-tDCS for 20 min combined with CT three-times-per-week for four weeks. The tDCS anode was over left dorsolateral prefrontal cortex (DLPFC) and cathode over vertex. Assessments were obtained prior to, after 6 sessions, 12 sessions and one-month after intervention.

RESULTS

No significant post-intervention differences were found between those receiving tDCS or sham-tDCS. Both groups demonstrated significant improvement on questionnaire measures of ADHD and executive function with mixed results seen on computerized performance measures. Overall, adverse effects were mild with no significant difference between groups. However, three children, all from the tDCS group, experienced headaches with two requiring temporary cessation and one requiring removal from the study.

CONCLUSIONS

Anodal tDCS to the DLPFC using the above protocol in children with ADHD did not demonstrate additional treatment benefits beyond that of CT.

The clinical utility of the continuous performance test and objective measures of activity for diagnosing and monitoring ADHD in children: a systematic review

Attention-deficit hyperactivity disorder (ADHD) is typically diagnosed using clinical observation and subjective informant reports. Once children commence ADHD medication, robust monitoring is required to detect partial or non-responses. The extent to which neuropsychological continuous performance tests (CPTs) and objective measures of activity can clinically aid the assessment and titration process in ADHD is not fully understood. This review describes the current evidence base for the use of CPTs and objectively measured activity to support the diagnostic procedure and medication management for children with ADHD. Four databases (PsycINFO, Medline, Allied and Complementary Medicine (AMED), and PsycARTICLES) were systematically searched to understand the current evidence base for (1) the use of CPTs to aid clinical assessment of ADHD; (2) the use of CPTs to aid medication management; and (3) the clinical utility of objective measures of activity in ADHD. Sixty relevant articles were identified. The search revealed six commercially available CPTs that had been reported on for their clinical use. There were mixed findings with regard to the use of CPTs to assess and manage medication, with contrasting evidence on their ability to support clinical decision-making. There was a strong evidence base for the use of objective measures of activity to aid ADHD/non-ADHD group differentiation, which appears sensitive to medication effects and would also benefit from further research on their clinical utility. The findings suggest that combining CPTs and an objective measure of activity may be particularly useful as a clinical tool and worthy of further pursuit.

Language Impairment in the Attention-Deficit/Hyperactivity Disorder Context

PURPOSE

Attention-deficit/hyperactivity disorder (ADHD) is a ubiquitous designation that affects the identification, assessment, treatment, and study of pediatric language impairments (LIs).

METHOD

Current literature is reviewed in 4 areas: (a) the capacity of psycholinguistic, neuropsychological, and socioemotional behavioral indices to differentiate cases of LI from ADHD; (b) the impact of co-occurring ADHD on children's LI; (c) cross-etiology comparisons of the nonlinguistic abilities of children with ADHD and specific LI (SLI); and (d) the extent to which ADHD contributes to educational and health disparities among individuals with LI.

RESULTS

Evidence is presented demonstrating the value of using adjusted parent ratings of ADHD symptoms and targeted assessments of children's tense marking, nonword repetition, and sentence recall for differential diagnosis and the identification of comorbidity. Reports suggest that the presence of ADHD does not aggravate children's LI. The potential value of cross-etiology comparisons testing the necessity and sufficiency of proposed nonlinguistic contributors to the etiology of SLI is demonstrated through key studies. Reports suggest that children with comorbid ADHD+LI receive speech-language services at a higher rate than children with SLI.

CONCLUSION

The ADHD context is multifaceted and provides the management and study of LI with both opportunities and obstacles.

Speech-Sound Disorders and Attention-Deficit/Hyperactivity Disorder Symptoms

PURPOSE

The purpose of this study was to examine the association of speech-sound disorders (SSD) with symptoms of attention-deficit/hyperactivity disorder (ADHD) by the severity of the SSD and the mode of transmission of SSD within the pedigrees of children with SSD.

PARTICIPANTS AND METHODS

The participants were 412 children who were enrolled in a longitudinal family study of SSD. Children were grouped on the basis of the severity of their SSD as determined by their scores on the Goldman-Fristoe Test of Articulation and history of an SSD. Five severity groups were compared: no SSD, resolved SSD, mild SSD, mild-moderate SSD, and moderate-severe SSD. Participants were also coded for comorbid language impairment (LI), based on scores on a standardized language test. Pedigrees of children were considered to represent bilineal inheritance of disorders if there was a history for SSD on both the maternal and paternal sides of the family. Parents completed the ADHD rating scale and a developmental questionnaire for each of their children.

RESULTS AND CONCLUSIONS

Children with moderate-severe SSD had higher ratings on the inattention and hyperactive/impulsivity scales than children with no SSD. Children whose family pedigrees demonstrated bilineal inheritance had higher ratings of inattention than children without bilineal inheritance. To determine the best predictors of ADHD ratings, multiple linear regression analyses were conducted. LI was more predictive of ADHD symptoms than SSD severity, bilineal inheritance of SSD, age, or gender. Findings support that LI rather than SSD is associated with ADHD.

Clinical and neuropsychological profile in a sample of children with attention deficit hyperactivity disorders

The aim of this study was to evaluate clinical and neuropsychological findings in children with suspicion of attention deficity hyperactivity disorder (ADHD). The assessment involved 150 children aged 7 to 14 referred to NANI at UNIFESP.

RESULTS

75 children (55 M and 20 F) fulfilled the criteria for ADHD, among which 35 were of the inattentive type, 28 of combined type and 12 were hyperactive/impulsive. There was negative correlation between the digit score and the Corsi test. Children with hyperactivity and impulsivity had a low performance for functional memory. Children with oppositional defiant disorder presented pattern changes in adaptability when there was a change in the rhythm the stimuli were presented and lower adaptation to time variability (Hit RT), in addition to higher rates of omission in the continuous performance test.

CONCLUSION

This study suggests multiple interrelations between the scores of neuropsychological battery useful for detailed delimitation of the clinical profile of children with ADHD.

Medications do not necessarily normalize cognition in ADHD patients

OBJECTIVE

Although ADHD medications are effective for the behavioral components of the disorder, little information exists concerning their effects on cognition, especially in community samples.

METHOD

A cross-sectional study of ADHD patients treated with three different ADHD drugs was conducted. Patients' performance on a computerized neurocognitive screening battery was compared to untreated ADHD patients and normal controls (NML). A total of 177 ADHD patients aged 10 to 18, achieved a favorable response to one of the following medications: Adderall XR (AMP), atomoxetine (ATMX), and Concerta (MPH-OROS) compared to 95 untreated ADHD patients and 101 NML.

RESULTS

Significant differences were detected between normals and untreated ADHD patients. Treated patients performed better than untreated patients but remained significantly impaired compared to normal subjects.

CONCLUSION

Even with optimal treatment, based on parents' and teachers' opinions, subtle and not-so-subtle neurocognitive impairments persisted in the ADHD patients. Some ADHD patients may require additional educational assistance, even in the face of successful medication treatment.

Performance of children with attention deficit hyperactivity disorder (ADHD) on a test battery of impulsiveness

Children with ADHD were compared to healthy controls on a task battery of cognitive control, measuring motor inhibition (Go/No-Go and Stop tasks), cognitive inhibition (motor Stroop and Switch tasks), sustained attention and time discrimination. Children with ADHD showed an inconsistent and premature response style across all 6 tasks. In addition they showed task-specific impairments in measures of sustained attention, time discrimination, and motor inhibition, but spared cognitive inhibition. Measures of impairment correlated with behavioral hyperactivity and with each other, suggesting that they measure interrelated aspects of a multifaceted construct of cognitive impulsiveness. The task battery as a whole showed 76% correct discrimination of cases and controls.

Evidence-based guidelines for management of attention-deficit/hyperactivity disorder in adolescents in transition to adult services and in adults: recommendations from the British Association for Psychopharmacology

Attention-deficit/hyperactivity disorder (ADHD) is an established diagnosis in children, associated with a large body of evidence on the benefits of treatment. Adolescents with ADHD are now leaving children's services often with no readily identifiable adult service to support them, which presents problems as local pharmacy regulations often preclude the prescription of stimulant drugs by general practitioners (GPs). In addition, adults with ADHD symptoms are now starting to present to primary care and psychiatry services requesting assessment and treatment. For these reasons, the British Association for Psychopharmacology (BAP) thought it timely to hold a consensus conference to review the body of evidence on childhood ADHD and the growing literature on ADHD in older age groups. Much of this initial guidance on managing ADHD in adolescents in transition and in adults is based on expert opinion derived from childhood evidence. We hope that, by the time these guidelines are updated, much evidence will be available to address the many directions for future research that are detailed here.

Intra-subject variability in attention-deficit hyperactivity disorder

BACKGROUND

This study is based on a comprehensive survey of the neuropsychological attention-deficit hyperactivity disorder (ADHD) literature and presents the first psychometric analyses of different parameters of intra-subject variability (ISV) in patients with ADHD compared to healthy controls, using the Continuous Performance Test, a Go-NoGo task, a Stop Signal Task, as well as N-back tasks.

METHODS

Data of 57 patients with ADHD and 53 age- and gender-matched controls were available for statistical analysis. Different parameters were used to describe central tendency (arithmetic mean, median), dispersion (standard deviation, coefficient of variation, consecutive variance), and shape (skewness, excess) of reaction time distributions, as well as errors (commissions and omissions).

RESULTS

Group comparisons revealed by far the strongest effect sizes for measures of dispersion, followed by measures of central tendency, and by commission errors. Statistical control of ISV reduced group differences in the other measures substantially. One (patients) or two (controls) principal components explained up to 67% of the inter-individual differences in intra-individual variability.

CONCLUSIONS

Results suggest that, across a variety of neuropsychological tests, measures of ISV contribute best to group discrimination, with limited incremental validity of measures of central tendency and errors. Furthermore, increased ISV might be a unitary construct in ADHD.

Effect of additional auditory and visual stimuli on continuous performance test (noise-generated CPT) in AD/HD children -- usefulness of noise-generated CPT

The continuous performance test (CPT) is designed to measure sustained attention quantitatively. Several CPTs are used clinically. We have made changes to the conventional type of visual CPT, by displaying auditory and visual noise along with target or non-target stimuli. By influencing the recognition of the subjects in this way, the changes were intended to increase the sensitivity of detection of inattention and impulsiveness, to make CPT more useful for diagnosis, and to examine the effect of noise on AD/HD children during CPT performance. Its usefulness for AD/HD diagnosis and the reaction of AD/HD children to noise were examined using newly developed computer software. Using this CPT analysis, a significant difference was observed in all measurements, except mean reaction time, between the control and AD/HD groups, showing that it was useful as a supplementary diagnostic method for AD/HD, and was more useful in the younger age group than in the older age group, as the same for conventional CPTs. As compared to no-noise sessions, commission and omission errors both increased significantly in auditory and visual noise sessions. Thus, analyzing the changes in measurements during noise sessions will improve the diagnosis of inattention and combined AD/HD subtypes. Furthermore, it was suggested that analysis of the effects of noise on AD/HD children will benefit their handling in an educational environment. Since omission errors were decreased in AD/HD children by noise during the CPT performance as compared to the control group, noise may induce attention in AD/HD children. The present study presents new findings on the responses to noise of AD/HD children during the CPT.

Relations between visual and auditory continuous performance tests in a clinical population: a descriptive study

Increased interest in auditory continuous performance tests (CPTs) exists despite the absence of a clear understanding about this procedure. The relation between auditory and visual CPTs and associations with IQ, achievement, and memory are evaluated in a referred sample of 634 children, ages 5.5 to 17.9. Age effects are found with CPT performance, regardless of modality. Total number correct or number of commissions correlations across tasks were greater than within-task number correct-number of commissions relations. The mean visual minus auditory correct difference score was 7.01; the mean commission difference score was -.85. Difference scores decreased with age and were not consistently related to other measures. Those with the lowest number correct on both CPTs (<25th percentile) were younger and had weaker short-term auditory memory and verbal learning skills; those falling in the problem quartile on commissions (>75th percentile) were younger and had poorer reading, verbal memory, and verbal learning. Total error scores (omissions + commissions) were inversely related to age. The auditory CPT has clinical utility, but other factors must be considered.

The Gordon Diagnostic System and WISC-III Freedom from Distractibility Index: validity in identifying clinic-referred children with and without ADHD

Gordon Diagnostic System and WISC-III scores for clinic-referred 6- to 16-yr.-olds (184 with ADHD Combined Type and 46 without ADHD) were analyzed to evaluate the combination of scores and cutpoints that maximized diagnostic accuracy. Using an "ADHD cutpoint" of IQ minus the GDS Composite score > or = 13, 87.8% of the children were correctly identified as having or not having ADHD. IQ minus Freedom from Distractibility > 0 yielded 73.5% accuracy. When the two meaures were combined to create new criteria (IQ minus GDS Composite > or = 13 or IQ minus Freedom from Distractibility > or = 11), diagnostic accuracy increased to 90.9% and negative predictive power improved substantially. Diagnostic agreement between the Gordon Diagnostic System and Freedom from Distractibility was 70%, suggesting that the two tests measure both similar and unique traits.

The ecological validity of delay aversion and response inhibition as measures of impulsivity in AD/HD: a supplement to the NIMH multimodal treatment study of AD/HD

Impulsivity is a primary symptom of the combined type of Attention Deficit/Hyperactivity Disorder (AD/HD). The Stop Signal Paradigm is premised upon a primary deficit in inhibitory control in AD/HD, whereas the Delay Aversion Hypothesis, by contrast, conceptualizes impulsivity in AD/HD, not as an inability to inhibit a response, but rather as a choice to avoid delay. This study compared the ecological validity of the Stop Signal Task (SST) and Choice-Delay Task (C-DT) measure of delay aversion, with respect to their relative utility in discriminating AD/HD children from normal control participants, and their correlations with classroom observations and with ratings of impulsivity and other core AD/HD symptoms on the Conners and SNAP-IV checklists. The tasks exhibited modest discriminant validity when used individually and excellent discriminant validity when used in combination. The C-DT correlated with teacher ratings of impulsivity, hyperactivity, and conduct problems, and with observations of gross motor activity, physical aggression, and an AD/HD composite score. The SST correlated with the observations only. These results suggest that delay aversion is associated with a broad range of AD/HD characteristics whereas inhibitory failure seems to tap a more discrete dimension of executive control.