Learning disabilities and ADHD: overlapping spectrumn disorders

Learning, attention, writing, and processing speed in typical children and children with ADHD, autism, anxiety, depression, and oppositional-defiant disorder

Learning, attention, graphomotor, and processing speed scores were analyzed in 149 typical control children and 886 clinical children with normal intelligence. Nonsignificant differences were found between control children and children with anxiety, depression, and oppositional-defiant disorder. Control children performed better than children with ADHD and autism in all areas. Children with ADHD and autism did not differ, except that children with ADHD had greater learning problems. Attention, graphomotor, and speed weaknesses were likely to coexist, the majority of children with autism and ADHD had weaknesses in all three areas, and these scores contributed significantly to the prediction of academic achievement.

Attention-deficit/hyperactivity disorder: a neuropsychological perspective towards DSM-V

Neuropsychological methods and techniques have much to offer in the evaluation of the individual suspected as having Attention-Deficit/Hyperactivity Disorder (ADHD). After a review of the historical evolution of the ADHD concept, incidence and prevalence, and DSM-IV criteria for diagnosis, especially as regards omission related to gender differences, and other associated cultural, familial, socioenvironmental, and subject influences, this paper describes a number of dilemmas and obstacles encountered in clinical practice. Included are the confounds associated with the wide range of possible comorbidities, the insufficiency of current DSM-IV criteria, the emergence of subtype differentiation and its impact on diagnosis and treatment. The complex relationship between neuropsychological constructs and ADHD, and obstacles to valid assessment are also addressed. The complexities associated with a thorough ADHD evaluation are viewed within an impressive and expansive existing scientific framework and recommendations are made for future directions.

ADHD drugs: values that drive the debates and decisions

Use of medication for treatment of ADHD (or its historical precursors) has been debated for more than forty years. Reasons for the ongoing differences of opinion are analyzed by exploring some of the arguments for and against considering ADHD a mental disorder. Relative to two important DSM criteria - that a mental disorder causes some sort of harm to the individual and that a mental disorder is the manifestation of a dysfunction in the individual - ADHD's classification as a mental disorder is found to be contentiously value-laden. The disagreements spill over to reasoning regarding appropriate management, because justification for a drug prescription is in part predicated on the idea that the drugs manage mental disorders. These debates do not appear to be nearing resolution, so individuals offering advice, or trying to decide whether ADHD drugs are appropriate for themselves or their children, may find it helpful to compare the values underlying various perspectives with their own.

ADHD and achievement: meta-analysis of the child, adolescent, and adult literatures and a concomitant study with college students

This article presents results from two interrelated studies. The first study conducted a meta-analysis of the published literature since 1990 to determine the magnitude of achievement problems associated with attention-deficit/hyperactivity disorder (ADHD). Effect sizes were significantly different between participants with and without ADHD (sample weighted r = .32, sample weighted d = . 71; p = .001). Effects were also examined according to the moderators of age, gender, achievement domain (reading, math, spelling), measurement method (standardized tests vs. grades, parent/teacher ratings, etc.), sample type (clinical vs. nonclinical), and system used to identify ADHD (DSM-III-R vs. DSM-IV). Significant differences emerged from the moderator comparisons. The second study, using averaged effect sizes from the first study as a baseline for comparison, investigated achievement levels for an understudied age group with ADHD, namely, college students. Unlike previous studies at the college level, the sample incorporated both student and parent ratings (N = 380 dyads). The results were comparable to outcomes from the meta-analysis for college students and adults. Analyses demonstrated modest (R = .21) but meaningful predictive validity across 1 year to end-of-first-year grades. However, unlike earlier studies with children and adolescents, student ratings were as predictive as parent ratings. Findings are discussed in terms of the impact of moderator variables on ADHD and achievement.

Cognitive and Symptom Profiles in High-Functioning Pervasive Developmental Disorder Not Otherwise Specified and Attention-Deficit/Hyperactivity Disorder

Age- and IQ-balanced 27 children with high-functioning (IQ>or=70) pervasive developmental disorder not otherwise specified (HPDDNOS) and 27 children with attention-deficit/hyperactivity disorder (ADHD) were compared on the Japanese version of Wechsler Intelligence Scale for Children Third Edition (WISC-III) and the Childhood Autism Rating Scale-Tokyo Version (CARS-TV). Compared with the ADHD children, the HPDDNOS children scored significantly lower on verbal comprehension, vocabulary, and comprehension, but significantly higher on block design. After controlling for the total CARS-TV score, the HPDDNOS children were significantly more abnormal on "relationships with people," "nonverbal communication," and "general impressions," but less abnormal on "near receptor responsiveness" and "activity level." These differences in cognitive and autistic symptom profiles may help professionals to distinguish clinically between both conditions.

Behavioral Problems and the Effects of Early Intervention on Eight-Year-Old Children with Learning Disabilities

OBJECTIVES

1) To investigate the comorbidity of verbal and nonverbal learning disability subtypes with several domains of behavior problems among 8-year-old children. 2) To determine whether receipt of an early intervention modified the association between childhood behavior problems and learning disabilities (LD).

METHODS

This is a secondary data analysis of the Infant Health and Development Program (IHDP), a randomized clinical trial of an early intervention provided between ages 0 and 3 involving 985 children born low birthweight and premature. The findings are based on a prospective follow-up of these children at 8 years of age.

RESULTS

Compared to children without verbal LD (VLD), those with VLD were twice as likely to exhibit clinical levels of total behavior problems and 89% more likely to exhibit externalizing behavior problems. Analysis of specific subscales of behavior revealed significant associations with anxious/depressed and withdrawn behaviors, as well as an increased likelihood of attention problems among children with VLD. No significant association was found between nonverbal LD (NVLD) and any type of behavior problem. Furthermore, there was a significant interaction between VLD and the intervention, in which the odds of internalizing behavior problems were greater among children with VLD. No interaction effect of the intervention occurred for any type of behavior problem among children with NVLD.

CONCLUSIONS

These findings provide evidence that distinct differences exist for different learning disability subtypes with regards to behavioral outcomes and the effects of early intervention services among 8-year-old children.

Characteristics of the sensory-motor, verbal and cognitive abilities of preschool boys with attention deficit/hyperactivity disorder combined type

The purpose of this study is to clarify the characteristics of sensory-motor, verbal and cognitive abilities of preschool boys with attention-deficit/hyperactivity disorder (ADHD) in order to provide information for their treatment and education at preschool age by teachers and professionals. For this purpose, 46 Japanese boys with ADHD-combined type (ADHD-C) whose ages ranged from 45 to 72 months were examined using the Japanese version of the Miller Assessment for Preschoolers (JMAP), and were compared with 46 Japanese boys matched for age and gender in the normative samples that served as the standardizations for the JMAP. The results showed that the ADHD-C group was significantly lower than the normative sample group both on the Total score and on each Index score (P < 0.01) with the exception of the Non-verbal Index. In particular, the number of boys with ADHD-C scoring below the 5th percentile on the Foundation Index (i.e. fundamental sensory-motor tests) was the highest among all index scores. The ADHD-C group had significantly lower scores than the normative sample group in equilibrium, postural control, fine motor of hand and tongue, motor praxis, articulation, memory related to the comprehension of long sentences, and visual construction. Because fundamental sensory-motor abilities were notably lower in the ADHD-C group than in the normative sample group, it is suggested that preschool boys with ADHD-C should be examined and treated for sensory-motor disabilities.

Diagnosing children's writing disabilities: different tests give different results

Writing problems are common in children with clinical disorders. However, there are significant intra-individual differences between the ability to spell words, construct sentences, and compose text. Therefore, achievement tests measuring different writing skills may not be consistent in identifying children who have these various writing disabilities. Our study compared scores on the Woodcock-Johnson Written Language subtests (which measure the ability to produce single words and single sentences) with scores on the Wechsler Individual Achievement Test Written Expression subtest (which assesses compositional writing skills) in 54 children referred by their teachers to a school psychologist for writing problems. The Woodcock-Johnson only identified 35% of children as having significant writing problems, whereas the Wechsler test identified 78%. Our study suggests that the latter is more likely than the Woodcock-Johnson to identify students who have problems in compositional writing.

Asymmetric deterioration of spatial awareness with diminishing levels of alertness in normal children and children with ADHD

BACKGROUND

There is growing literature suggesting that some children diagnosed with attention deficit hyperactivity disorder (ADHD) can show a significant bias in attention away from left space. Here we examine mechanisms that may underpin these effects in both clinical and non-clinical child populations. Unilateral spatial inattention (unilateral neglect) is a commonly reported consequence of stroke in adults. Although for most patients the problem is relatively transient, persistent forms of neglect are almost exclusively associated with right hemisphere lesions. It has been suggested that this chronicity may result from co-existing disruption to right hemisphere dominant systems that mediate alertness. Here we present two studies examining the relationship between sustained attention and left spatial awareness in childhood.

METHOD

In the first, normal children without the ADHD diagnosis were administered a non-spatial test of sustained attention/alertness. Children who performed poorly at this task, relative to their more attentive peers, showed a modest but reliable delay in awareness of left-sided visual information. Furthermore, attention towards the left declined for both groups as a function of time-on-task, suggesting a significant within-subject modulatory effect of alertness on spatial awareness. The second study examines this relationship in children referred to clinical services for attention problems. Irrespective of their final diagnosis, children were divided into two groups according to their performance in sustained attention/alertness tasks.

RESULTS

The results suggest that, regardless of the children's clinical diagnosis, diminished sustained attention/alertness levels formed the strongest predictor of relatively delayed awareness of information presented within left visual space. Two children within this group exhibited signs of hitherto undetected spatial neglect as severe as that observed in some brain-injured adults.

CONCLUSIONS

Clinical and theoretical implications are discussed.

Delinquency, hyperactivity, and phonological awareness: a comparison of adolescents with ODD and ADHD

The incidence of reading disabilities in children with attention deficit hyperactivity disorder (ADHD) has been found at a higher proportion than would be expected by chance. This study explored the relationship between reading problems-comprehension and phonological awareness, and externalizing behaviors-hyperactivity (ADHD), and oppositional defiant disorder (ODD). One hundred boys from Central Texas area alternative education schools between the ages of 11 and 15 were grouped by categories: ADHD-Combined Type (ADHD:C), ODD only, a combination of ADHD:C and ODD, and children without either ADHD or ODD. Results indicated that there were no significant differences among the four groups in terms of reading skills. However, findings suggest a significant negative linear relationship between hyperactivity and reading skills. Application of these findings is discussed.

Similarities and differences in Wechsler Intelligence Scale for Children--Third Edition (WISC-III) profiles: support for subtest analysis in clinical referrals

Our study supports the reliability and validity of profile analysis in children with neurobiological disorders. Three mutually exclusive WISC-III profiles were identified that characterized the majority of children with autism (low coding or Freedom from Distractibility Index with low Comprehension), attention deficit hyperactivity disorder and learning disability (low Coding or FDI without low comprehension), and brain injury (low Performance without low Coding or FDI). The profiles suggest attention, writing, and performance speed deficits in autism, ADHD, and LD; global visual-motor problems in brain injury; and specific difficulty with language comprehension and social reasoning in autism. Children with anxiety, depression, and behavior disorders did not exhibit distinct profiles. Our profile analysis is based on the simple rank ordering of standard scores. The profiles are clinically useful because they may alert clinicians to certain diagnostic possibilities, they reveal characteristic strengths and weaknesses that have implications for educational intervention, and they are consistent with preliminary WISC-IV data.

An epidemiological study of number processing and mental calculation in Greek schoolchildren

The aim of this study was to validate and standardize an instrument for the diagnosis of developmental dyscalculia (mathematics disorder) in a Greek population and to obtain relevant epidemiological data. We used the Neuropsychological Test Battery for Number Processing and Calculation in Children (NUCALC) in a community sample of 240 students ages 7 to 11 years from urban and rural schools. There were no differences between genders in arithmetical performance; however, the effects of grade and socioeconomic level were significant. Prevalence was higher in the rural than in the urban area. A cross-cultural comparison of the Greek data with those obtained with the same instrument in other countries in schoolchildren of the same age was performed.

Ability profiles in children with autism: influence of age and IQ

To understand the effect of IQ and age on ability in children with autism, psychological data were analyzed for 164 3- to 15-year-olds with autism (IQs 14-143). As age increased, so did IQ, which probably reflects both an actual increase in IQ over time and the likelihood that brighter children are diagnosed later. Early in life, 67 percent had normal motor and delayed speech milestones. Verbal IQ continued to lag behind non-verbal IQ during the preschool years. By school age, the gap between verbal and non-verbal IQs had closed. Visual reasoning exceeded graphomotor scores for all children, and surpassed IQ for most. Graphomotor scores were significantly below IQ for both high-IQ groups. For school-age children with low IQs, math, spelling, and writing scores were consistent with IQ and reading was above IQ. School-age children with high IQs had average reading, math, and spelling scores and a weakness in writing.

Three-year course of learning disorders in special education students classified as behavioral disorder

OBJECTIVE

To investigate the 3-year course of learning disorders (LDs) and academic achievement in a sample of students with psychiatric disorders who were newly classified by the special education category of behavioral disorder (BD).

METHOD

The occurrence of four definitions for LD (both discrepancy and low achievement) based on the WISC-R and the Woodcock-Johnson Psychoeducational Battery was followed in 81 students with BD from the time of their enrollment in BD classes to their first reevaluation after 3 years. Odds ratios (ORs) were used to measure stability of LDs in these students.

RESULTS

The prevalence of any LD was 64.2% at baseline and 61.7% at follow-up. Most of the 10 possible LD categories showed significant ORs, and the average OR was 21.9. At follow-up after 3 years, students both with and without LD at baseline had approximately the same achievement standard scores in reading and mathematics, but a significantly lower score for written language. Standard scores for the students without LD consistently were significantly higher than the scores for students with comorbid LD.

CONCLUSION

LDs in this unique sample of students with psychiatric disorders remained common and generally stable over the first 3 years.

Separating genuine cases of reading disability from reading deficits caused by predominantly inattentive ADHD behavior

Conventional methods of differentiating reading disability (RD) caused by deficits in decoding skills or comprehension from poor reading performance caused by inconsistent attention associated with attention-deficit/hyperactivity disorder (ADHD) have produced equivocal results. This study presents a model of differential diagnosis of attentional problems and RD that differs from these conventional approaches. The new diagnostic procedure uses intraindividual differences seen in the performance of at-risk learners on tasks related to reading that vary in their sensitivity to the sustained attention required for successful performance. The hypothesis is that children with inconsistent attention would perform more poorly on tests that require sustained attention, such as listening comprehension, than on tests that are more tolerant of inattention, such as reading comprehension. Such differences would not be seen in the test scores of children who have only RD, because their performance is determined more by the difficulty level of the reading tests than by the degree of sensitivity of the task to attention. The validity of this new model was evaluated by determining the capability of the differences seen in the scores of tests that differ in their sensitivity to sustained attention to predict the degree of inconsistency in sustained attention as measured by a continuous performance test. The data obtained from 39 children who are at risk for RD suggest that this is a viable model.