Clinical utility of the Vanderbilt ADHD Rating Scale for ruling out comorbid learning disorders

Locomotor-cognitive dual-tasking in children with developmental coordination disorder

Introduction

Children with Developmental Coordination Disorder (DCD) demonstrate deficits in predictive motor control and aspects of cognitive control compared with their typically developing (TD) peers. Adjustment to dynamic environments depends on both aspects of control and the deficits for children with DCD may constrain their ability to perform daily actions that involve dual-tasking. Under the assumption that motor-cognitive integration is compromised in children with DCD, we examined proportional dual-task costs using a novel locomotor-cognitive dual-task paradigm that enlisted augmented reality. We expect proportional dual-task performance costs to be greater for children with DCD compared to their TD peers.

Methods

Participants were 34 children aged 6-12 years (16 TD, 18 DCD) who walked along a straight 12 m path under single- and dual-task conditions, the cognitive task being visual discrimination under simple or complex stimulus conditions presented via augmented reality. Dual-task performance was measured in two ways: first, proportional dual-task costs (pDTC) were computed for cognitive and gait outcomes and, second, within-trial costs (p-WTC) were measured as the difference on gait outcomes between pre- and post-stimulus presentation.

Results

On measures of pDTC, TD children increased their double-limb support time when walking in response to a dual-task, while the children with DCD increased their locomotor velocity. On p-WTC, both groups increased their gait variability (step length and step width) when walking in response to a dual-task, of which the TD group had a larger proportional change than the DCD group. Greater pDTCs on motor rather than cognitive outcomes were consistent across groups and method of dual-task performance measurement.

Discussion

Contrary to predictions, our results failed to support dramatic differences in locomotor-cognitive dual-task performance between children with DCD and TD, with both groups tending to priorities the cognitive over the motor task. Inclusion of a within-trial calculation of dual-task interference revealed an expectancy effect for both groups in relation to an impending visual stimulus. It is recommended that dual-task paradigms in the future continue to use augmented reality to present the cognitive task and consider motor tasks of sufficient complexity to probe the limits of performance in children with DCD.

Neurodevelopmental Effects of Perinatal TCDD Exposure Differ from Those of Other PCDD/Fs in Vietnamese Children Living near the Former US Air Base in Da Nang, Vietnam

This study reports that children exposed to 2,3,7,8-tetra-chlorodibenzo-p-dioxin (TCDD), the major toxin in Agent Orange, from the breast milk of mothers residing near the former Da Nang US air base in Vietnam may have specific alterations in higher brain functions, resulting in social and communication deficits, including autism spectrum disorder (ASD). After the age of 8 years, girls with high TCDD showed increased attention deficit hyperactivity disorder (ADHD)-like behaviors and altered mirror neuron activity, which is often observed in children with ASD. However, no significant relationship between autistic traits and toxic equivalency values of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (TEQ-PCDD/Fs) was found in these children. Notably, boys with high levels of TEQ-PCDD/Fs showed poor language and motor development in the first 3 years of life, although boys with high TCDD levels did not. However, at 8 years of age, boys with high TCDD showed reading learning difficulties, a neurodevelopmental disorder. These findings suggest that perinatal TCDD exposure impacts social-emotional cognitive functions, leading to sex-specific neurodevelopmental disorders-learning difficulty in boys and ADHD in girls. Future studies with a greater number of children exposed to high levels of TCDD are necessary to estimate the threshold values for neurodevelopmental effects.

Dyslexia and Attention Deficit Hyperactivity Disorder Associated to a De Novo 1p34.3 Microdeletion

The authors report on a boy with dyslexia and attention deficit hyperactivity disorder. A protocol of standardized tests assessed the neuroadaptive profile, allowing deep neuropsychiatric phenotyping. In addition to the diagnosis of dyslexia and attention deficit hyperactivity disorder, such methodology led to endeavor cognitive, adaptive, and academic skills. Chromosomal microarray analysis detected a 452.4 Kb de novo heterozygous microdeletion in chromosomal region 1p34.3, including seven OMIM genes. The authors took a thorough evaluation of the association to the phenotype of the deleted genes. Further reports could strengthen such association.

Do Executive Dysfunction, Delay Aversion, and Time Perception Deficit Predict ADHD Symptoms and Early Academic Performance in Preschoolers

Children with attention deficit/hyperactivity disorder (ADHD) are commonly observed to have learning difficulties. This study examined how three neuropsychological constructs—executive dysfunction, delay aversion, and time perception—were associated with ADHD symptoms and early academic performance in preschoolers at risk of ADHD. One hundred and thirty-one preschoolers (70 boys, 53%) aged 4 to 6 (M = 5.31 years) were assessed on their ADHD-related behaviors, neuropsychological functioning, word reading, and math abilities at two time points one year apart. Factor analysis indicated that inhibitory and attentional control deficit, delay aversion, and time perception/working memory deficit were three dissociable factors. Among the three factors, inhibitory and attentional control measured at Time 1 was the strongest predictor of ADHD symptoms at both Time 1 and Time 2. Time perception was closely related to working memory, and they predicted word reading and numeration across time most strongly among other neuropsychological constructs. Our findings suggested that inhibitory and attentional control, delay aversion, and time perception are dissociable neuropsychological deficits underlying ADHD symptoms in preschoolers. Poor time perception may serve as a marker for the early identification of preschoolers with potential learning problems, and a possible target of intervention for ADHD.

Tradução e adaptação para português da Vanderbilt ADHD Diagnostic Teacher Rating Scale: um estudo piloto

Este estudo integra uma investigação mais ampla, cujo propósito foi analisar o impacto da Perturbação de Hiperatividade/Défice de Atenção (PHDA) em contexto escolar, a nível académico, comportamental e social. A Vanderbilt Adhd Diagnostic Teacher Rating Scale (VADTRS) – Escala Vanderbilt de Diagnóstico de PHDA para Professores (EVDPP) - foi traduzida e adaptada para Português Europeu. 76 professores do 1.º ciclo da ilha de São Miguel (Açores) preencheram a EVDPP para 105  alunos diagnosticados com PHDA ou em avaliação, com idades compreendidas entre os 6 e os 11 anos, 85.7% são do género masculino e 14.3% do  feminino. Os resultados demonstram a validade interna da escala, com alfas de Chronbach a situarem-se entre os .80 e .94 nas diferentes dimensões, corroborando outros estudos internacionais. Estes dados preliminares sugerem que a EVDPP pode ser um instrumento extremamente útil para as equipas multidisciplinares na sinalização, diagnóstico e caraterização dos principais problemas da PHDA em contexto escolar.

Comorbidity of reading disabilities and ADHD: Structural and functional brain characteristics

Reading disabilities (RD) and attention-deficit/hyperactivity disorder (ADHD) are two of the most common developmental disorders. RD and ADHD frequently co-occur, which raises questions about how the disorders interact and to what extent they can be differentiated. To date, the underlying neural mechanisms leading to RD-ADHD comorbidity (COM) are not understood. In this study, structural and functional magnetic resonance imaging (fMRI) were combined with comprehensive behavioral testing in order to characterize the behavior, brain structure, and neural correlates of executive function, phonological processing and reading fluency in 60 children with clinical diagnoses of RD, ADHD, or COM, and controls. Whole-brain analyses of variance were performed on cortical thickness values and on the data of the three fMRI tasks to investigate overall group differences. To validate these findings, a region of interest analysis was performed in regions that have previously been shown to exhibit group differences in children with RD or ADHD using the same paradigms. The neuroimaging results demonstrated structural and functional atypicalities for COM in regions that are frequently associated with deficits in children with isolated ADHD or RD. A combination of shared and distinctive brain alterations between the clinical groups was identified, supporting the multiple deficit model for ADHD, RD, and its comorbidity.

Differential effect of reading training on functional connectivity in children with reading difficulties with and without ADHD comorbidity

A comorbidity of attention deficit hyperactivity disorder (ADHD) with reading difficulties (RD) is common in children. However, children with ADHD+RD have a different reading and executive functions (EF) profile than children with RD alone. We compared the effect of an EF-based intervention on neural circuits related to EF in children with RD and those with ADHD+RD. Functional connectivity MRI data from a lexical decision task suggest that the RD-alone group showed greater improvement in EF and reading tests and greater functional connectivity between networks related to both higher-and lower-level visual processing and those related to ventral attention and dorsal attention, as well as semantic processing. Children with ADHD+RD showed greater connectivity between networks related to attention and dorsal attention and those related to visual processing and EF. Results are consistent with the Cognitive Subtype hypothesis and suggest that RD and ADHD+RD, although related behaviourally, are distinct disorders with regard to network response and connectivity during reading and after an EF-based intervention.

The written expression abilities of adolescents with Attention-Deficit/Hyperactivity Disorder

Students with Attention-Deficit/Hyperactivity Disorder (ADHD) often experience deficits in academic achievement. Written expression abilities in this population have not been extensively studied but existing prevalence estimates suggest that rates of comorbid writing underachievement may be substantially higher than rates of comorbid reading and mathematics underachievement. The current study examined written expression abilities in a school-based sample of 326 middle school age students with ADHD. The prevalence of written expression impairment, the associations between written expression and academic outcomes, and specific patterns of written expression were investigated. Students with ADHD in this sample experienced written expression impairment (17.2-22.4%) at a similar rate to reading impairment (17.0-24.3%) and at a slightly lower rate than mathematics impairment (24.7-36.3%). Students' written expression abilities were significantly associated with school grades and parent ratings of academic functioning, above and beyond the influence of intelligence. Analyses of patterns suggest that students with ADHD exhibit greater deficits in written expression tasks requiring organization and attention to detail, especially in the context of a complex task.

Longitudinal study of very low birth weight infants until 9years of age; attention deficit hyperactivity and autistic features are correlated with their cognitive functions

BACKGROUND

Increasing attention has been given to neuro-developmental problems of very low birth weight infants (VLBWIs) at school age. However, it remains unknown whether their neuro-cognitive function and psychiatric symptoms are mutually associated.

AIM

The aim of this study was to investigate the characteristics of neuro-cognitive functions in VLBWIs and their relationship with psychiatric symptoms.

METHODS

A total of 160 VLBWIs who were born at our institute between 2001 and 2005 were recruited consecutively and followed up until nine years of age. The developmental profiles were obtained from 77 children (45 males and 32 females) at six to nine years of age using the ADHD Rating Scale-Fourth edition (ADHD-RS), Autism Screening Questionnaire-Japanese version (ASQ-J) and the Wechsler Intelligence Scale for Children-Third edition (WISC-III).

RESULTS

The full-scale intelligence quotient did not significantly differ between the male and female VLBWIs (median: 91 vs. 99, p=0.17). The males had higher total scores (median: 13 vs. 4, p<0.01) and higher scores on the subscales of Inattention (8 vs. 2, p<0.01) and Hyperactivity-Impulsivity (5 vs. 1, p<0.01) of the ADHD-RS compared with the females. The Verbal Comprehension Index (VCI) of the WISC-III was inversely correlated with the total scores of the ASQ-J for all VLBWIs (n=77, rc: -0.32, 95% CI: -0.19 to -0.01, p=0.04). We also observed that the Freedom from Distractibility Index (FDI) of the WISC-III was significantly correlated with the Inattentive scores of the ADHD-RS (n=45, rc: -0.18, 95% CI: -0.35 to -0.02, p=0.03) in male, but not female VLBWIs.

CONCLUSIONS

We herein report that the VCI and FDI of the WISC-III were correlated with the autism spectrum disorder and attention deficit hyperactivity disorder symptoms, respectively, in male VLBWIs.

"Complex" attention-deficit hyperactivity disorder, more norm than exception? Diagnoses and comorbidities in a developmental clinic

OBJECTIVE

Current recommendations for evaluation and diagnosis of attention-deficit hyperactivity disorder (ADHD) are meant for primary care settings and may not adequately address the needs of children seen in subspecialty developmental-behavioral pediatric settings who may have higher rates of comorbid developmental, learning, and psychiatric disorders. The authors sought to characterize the diagnostic complexity of school-aged children diagnosed with ADHD after comprehensive multidisciplinary evaluation in a subspecialty developmental-behavioral pediatric clinic.

METHODS

The authors conducted a retrospective medical record review of 144 patients aged 7 to 11 years who were consecutively evaluated by an interdisciplinary team (developmental-behavioral pediatrician, psychologist, educator) in a school-age clinic within a developmental-behavioral pediatrics tertiary care center from January 1, 2009 to December 31, 2009.

RESULTS

After comprehensive evaluation, rates of ADHD diagnosis increased from 32.6% (n = 47) preevaluation to 54.2% (n = 78) postevaluation (p < .0001). Rates of learning disorders among children receiving a final diagnosis of ADHD increased from 2.6% (n = 2) preevaluation to 50% (n = 39) postevaluation. (p < .0001). Among children receiving a final diagnosis of ADHD, 73.1% (n = 57) were diagnosed with at least 1 comorbid psychiatric, developmental, or learning disorder.

CONCLUSIONS

Among school-aged children diagnosed with ADHD in a developmental-behavioral pediatric subspecialty setting, a comprehensive evaluation including developmental, neuropsychological, and educational assessments yielded high rates of comorbid psychiatric, developmental, and learning disorders. This supports the need to provide comprehensive interdisciplinary assessment for such children to ensure the identification and treatment of not only the core symptoms of ADHD but also the comorbidities that may otherwise go unrecognized and therefore not optimally treated.

Addressing the problem of ADHD medication as neuroenhancements

The prevalence of attention deficit hyperactivity disorder (ADHD) diagnoses is rising. ADHD is closely linked to its treatment with medications such as methylphenidate and amphetamines, which have popular appeal as neuroenhancement drugs by persons without a neurological disorder. The three main reasons for the increase in ADHD medication demand, production, and consumption are a) the inclusion of milder ADHD diagnoses; b) the vast marketing of ADHD medications by the pharmaceutical industry; and c) the illegal diversion of controlled ADHD medication to consumers seeking stimulants as neuroenhancements. Rapidly rising rates of any neurological disorder - especially a behaviorly-defined disorder closely linked to potent medications currently prescribed to more than 5% of the population - deserves ongoing scrutiny. Major social and ethical problems arise from vague-symptom medicalization, neurological disorder trivialization, medication overuse, and controlled substances diversion to healthy persons for nonmedical purposes. We argue against the 'spectrumization' of ADHD in an effort to curtail further diagnosis creep.

Neuropsychopathological comorbidities in learning disorders

BACKGROUND

Learning Disorders (LD) are complex diseases that affect about 2-10% of the school-age population. We performed neuropsychological and psychopathological evaluation, in order to investigate comorbidity in children with LD.

METHODS

Our sample consisted of 448 patients from 7 to 16 years of age with a diagnosis of LD, divided in two subgroups: Specific Learning Disorders (SLD), including reading, writing, mathematics disorders, and Learning Disorders Not Otherwise Specified (LD NOS).

RESULTS

Comorbidity with neuropsychopathologies was found in 62.2% of the total sample. In the LSD subgroup, ADHD was present in 33%, Anxiety Disorder in 28.8%, Developmental Coordination Disorder in 17.8%, Language Disorder in 11% and Mood Disorder in 9.4% of patients. In LD NOS subgroup, Language Disorder was present in 28.6%, Developmental Coordination Disorder in 27.5%, ADHD in 25.4%, Anxiety Disorder in 16.4%, Mood Disorder in 2.1% of patients. A statistically significant presence was respectively found for Language and Developmental Coordination Disorder comorbidity in LD NOS and for ADHD, mood and anxiety disorder comorbidity in SLD subgroup.

CONCLUSIONS

The different findings emerging in this study suggested to promote further investigations to better define the difference between SLD and LD NOS, in order to improve specific interventions to reduce the long range consequences.

Children with ADHD symptoms have a higher risk for reading, spelling and math difficulties in the GINIplus and LISAplus cohort studies

Attention-deficit/hyperactivity disorder (ADHD) and dyslexia belong to the most common neuro-behavioral childhood disorders with prevalences of around 5% in school-aged children. It is estimated that 20–60% of individuals affected with ADHD also present with learning disorders. We investigated the comorbidity between ADHD symptoms and reading/spelling and math difficulties in two on-going population-based birth cohort studies. Children with ADHD symptoms were at significantly higher risk of also showing reading/spelling difficulties or disorder (Odds Ratio (OR) = 2.80, p = 6.59×10⁻¹³) as compared to children without ADHD symptoms. For math difficulties the association was similar (OR = 2.55, p = 3.63×10⁻⁰⁴). Our results strengthen the hypothesis that ADHD and learning disorders are comorbid and share, at least partially, the same underlying process. Up to date, it is not clear, on which exact functional processes this comorbidity is based.

Comorbidity of LD and ADHD: implications of DSM-5 for assessment and treatment

Attention-deficit/hyperactivity disorder (ADHD) and learning disability (LD) can co-occur for a significant minority of children with each disorder. A total of 17 studies (2001-2011) examining ADHD-LD comorbidity were reviewed, revealing a higher mean comorbidity rate (45.1%) than has been obtained previously. Higher comorbidity may be the result of including students with writing disorders, not just reading and/or math disabilities. Proposed DSM-5 criteria for both disorders will likely affect comorbidity rates; however, it is unclear whether such rates will increase or decrease. Regardless of the specific impact of DSM revisions, academic skill and/or performance deficits should be assessed for students with ADHD as part of screening, comprehensive evaluation, and treatment monitoring. Comprehensive intervention services for students with comorbid ADHD and LD will require empirically supported treatment strategies that address both disorders and that are implemented across school and home settings.