A cross-sectional study to assess the prevalence of DSM-5 specific learning disorders in representative school samples from the second to sixth grade in Brazil

Mathematics Skills in Epilepsy: A Systematic Review and Meta-Analysis

Mathematics incorporates a broad range of skills, which includes basic early numeracy skills, such as subitizing and basic counting to more advanced secondary skills including mathematics calculation and reasoning. The aim of this review was to undertake a detailed investigation of the severity and pattern of early numeracy and secondary mathematics skills in people with epilepsy. Searches were guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Twenty adult studies and 67 child studies were included in this review. Overall, meta-analyses revealed significant moderate impairments across all mathematics outcomes in both adults (g= -0.676), and children (g= -0.593) with epilepsy. Deficits were also observed for specific mathematics outcomes. For adults, impairments were found for mathematics reasoning (g= -0.736). However, two studies found that mathematics calculation was not significantly impaired, and an insufficient number of studies examined early numeracy skills in adults. In children with epilepsy, significant impairments were observed for each mathematics outcome: early numeracy (g= -0.383), calculation (g= -0.762), and reasoning (g= -0.572). The gravity of impairments also differed according to the site of seizure focus for children and adults, suggesting that mathematics outcomes were differentially vulnerable to the location of seizure focus.

Evaluation of Retinal Nerve Fiber Layer, Ganglion Cell Thickness, and Macular Thickness in Children With Comorbid Specific Learning Disorder and Attention-Deficit Hyperactivity Disorder

PURPOSE

To investigate the changes in ocular optical coherence tomography (OCT) findings in the comorbidity of attention-deficit hyperactivity disorder (ADHD) and specific learning disorder (SLD).

METHODS

This study included 40 individuals diagnosed as having ADHD along with comorbid SLD, 40 individuals diagnosed as having only ADHD, and 40 individuals with no psychiatric disorders. OCT assessments were performed on eyes of the participants to obtain retinal nerve fiber layer (RNFL) thickness, ganglion cell complex (GCC) thickness, and macular thickness measurements.

RESULTS

In total, 240 eyes were evaluated. The right and left eyes were not significantly different in terms of RNFL, GCL, and macular thickness within groups (P > .05). RNFL thickness was measured and compared across four quadrants (superior, inferior, temporal, and nasal). Although these values were not significantly different between the groups (P > .05), RNFL was observed to be thinner in children with comorbid ADHD and SLD in all quadrants. Similarly, GCL and macular thickness measurements were also not different between the groups (P > .05).

CONCLUSIONS

Considering that retinal nerve fibers can be seen as an extension of the brain in the embryologic context, the results showed that OCT findings alone are not sufficient to detect the changes in ADHD and SLD comorbidity. The authors suggest that OCT is more useful in the etiology and follow-up of neurodegenerative diseases rather than neurodevelopmental disorders. [J Pediatr Ophthalmol Strabismus. 2024;61(2):128-136.].

Comorbidity between reading disability and ADHD in a community sample: Implications for academic, social, and neuropsychological functioning

To better understand the implications of comorbidity between reading disability (RD) and attention-deficit / hyperactivity disorder (ADHD), a sample of 225 participants with RD without ADHD, 139 participants with both RD and ADHD, and 1,502 children without reading or attentional difficulties was recruited through five large public school districts. In comparison to the group without RD or ADHD, both groups with RD exhibited elevations of comorbid internalizing and externalizing disorders and significant global, academic, and social impairment. However, the group with both RD and ADHD was most impaired on most measures, and analyses of neuropsychological measures indicate that the co-occurrence of RD and ADHD may be due at least in part to weaknesses in cognitive processing speed and working memory that are most severe in the comorbid group. These results indicate that psychoeducational assessments of RD should always screen for ADHD and other emotional and behavioral difficulties, and that when RD and ADHD co-occur interventions are likely to be needed for both disorders.

An approach for prevention planning based on the prevalence and comorbidity of neurodevelopmental disorders in 6-year-old children receiving primary care consultations on the island of Menorca

BACKGROUND

Few studies have estimated the real prevalence of neurodevelopmental disorders according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) in Spain and worldwide. However, there are disparate prevalence figures. We consider research in this field essential to improve early detection, secondary prevention, and health planning.

METHODS

The Minikid ADHD and TICS-Mini International Neuropsychiatric Interview for Children and Adolescents, the Autism Spectrum Quotient (Children's version, AQ- Child) and a protocol of general medical questions were administered for screening purposes. The PROLEXIA battery for children aged from 4 to 6 years was used for direct assessments. Parents provided information on emotional, medical, and school aspects. The final population evaluated using these tools consisted of 291 6-year-old subjects.

RESULTS

The overall risk of presenting with a neurodevelopmental disorder was 55.4%. A 23.4% risk of presenting with attention-deficit/hyperactivity disorder (ADHD) in any modality (inattentive, hyperactive-impulsive and combined), a 2.8% risk of developing autism spectrum disorder (ASD), a 30.6% risk of presenting with a learning disorder with reading difficulties, a 5.5% risk of tics and a 22.5% risk of language problems (incomprehensible language or minor language problems) were detected in the sample. The most common combination of disorders was learning and language difficulties, accounting for 6.9% of the sample. The second most frequent combination was the presence of learning and language difficulties and ADHD, accounting for 4.5% of the sample.

CONCLUSIONS

The prevalence of risks detected in our sample seems to be consistent with national and international studies. A significant proportion of our sample had never been previously diagnosed (85%), so early detection programs are recommended.

Neurodevelopmental disorders among Spanish school-age children: prevalence and sociodemographic correlates

BACKGROUND

Prevalence estimates of neurodevelopmental disorders (ND) are essential for treatment planning. However, epidemiological research has yielded highly variable rates across countries, including Spain. This study examined the prevalence and sociodemographic correlates of ND in a school sample of Spanish children and adolescents.

METHODS

The Child Behaviour Checklist/Teacher's Report Form/Youth Self-Report and the Conners' Rating Scales were administered for screening purposes. Additionally, teachers provided information on reading and writing difficulties. Subjects who screened positive were interviewed for diagnostic confirmation according to the Diagnostic and Statistical Manual of Mental Disorders criteria. The final population comprised 6834 students aged 5-17. Multivariate analyses were performed to determine the influence of gender, age, educational stage, school type, socioeconomic status (SES), and ethnicity on the prevalence estimates.

RESULTS

A total of 1249 (18.3%) subjects met criteria for at least one ND, although only 423 had already received a diagnosis. Specifically, the following prevalence rates were found: intellectual disabilities (ID), 0.63%; communication disorders, 1.05%; autism spectrum disorder (ASD), 0.70%; attention-deficit/hyperactivity disorder (ADHD), 9.92%; specific learning disorder (SLD), 10.0%; and motor disorders, 0.76%. Students of foreign origin and from low SES evidenced higher odds of having ID. Boys were more likely to display ASD or a motor disorder. Age, SES, and ethnicity were significant predictors for SLD, while communication disorders and ADHD were also associated with gender.

CONCLUSIONS

The prevalence of ND among Spanish students is consistent with international studies. However, a substantial proportion had never been previously diagnosed, which emphasise the need for early detection and intervention programmes.

Prevalence of Specific Learning Disorders (SLD) Among Children in India: A Systematic Review and Meta-Analysis

Background:

Specific learning disorders (SLD) comprise varied conditions with ongoing problems in one of the three areas of educational skills–reading, writing, and arithmetic–which are essential for the learning process. There is a dearth of systematic reviews focused exclusively on the prevalence of SLD in India. Hence, this study was done to estimate the prevalence of SLD in Indian children.

Methods:

A systematic search of electronic databases of MEDLINE, Embase, PsycINFO, and CINAHL was conducted. Two authors independently assessed the eligibility of the full-text articles. The third author reassessed all selected studies. A standardized data extraction form was developed and piloted. The pooled prevalence of SLDs was estimated from the reported prevalence of eligible studies, using the random-effects model.

Results:

Six studies of the systematic review included the diagnostic screening of 8133 children. The random-effects meta-analysis showed that the overall pooled prevalence of SLD in India was 8% (95% CI = 4–11). The tools used to diagnose SLD in the studies were the National Institute of Mental Health and Neurosciences (NIMHANS)-SLD index and the Grade Level Assessment Device (GLAD).

Conclusions:

Nearly 8% of children up to 19 years have SLD. There are only a few high-quality, methodologically sound, population-based epidemiological studies on this topic. There is a pressing need to have large population-based surveys in India, using appropriate screening and diagnostic tools. Constructing standardized assessment tools, keeping in view the diversity of Indian culture, is also necessary.

Discerning Developmental Dyscalculia and Neurodevelopmental Models of Numerical Cognition in a Disadvantaged Educational Context

Developmental Dyscalculia (DD) signifies a failure in representing quantities, which impairs the performance of basic math operations and schooling achievement during childhood. The lack of specificity in assessment measures and respective cut-offs are the most challenging factors to identify children with DD, particularly in disadvantaged educational contexts. This research is focused on a numerical cognition battery for children, designed to diagnose DD through 12 subtests. The aims of the present study were twofold: to examine the prevalence of DD in a country with generally low educational attainment, by comparing z-scores and percentiles, and to test three neurodevelopmental models of numerical cognition based on performance in this battery. Participants were 304 Brazilian school children aged 7–12 years of both sexes (143 girls), assessed by the Zareki-R. Performances on subtests and the total score increase with age without gender differences. The prevalence of DD was 4.6% using the fifth percentile and increased to 7.4% via z-score (in total 22 out of 304 children were diagnosed with DD). We suggest that a minus 1.5 standard deviation in the total score of the Zareki-R is a useful criterion in the clinical or educational context. Nevertheless, a percentile ≤ 5 seems more suitable for research purposes, especially in developing countries because the socioeconomic environment or/and educational background are strong confounder factors to diagnosis. The four-factor structure, based on von Aster and Shalev’s model of numerical cognition (Number Sense, Number Comprehension, Number Production and Calculation), was the best model, with significant correlations ranging from 0.89 to 0.97 at the 0.001 level.

Current state of knowledge on the prevalence of neurodevelopmental disorders in childhood according to the DSM-5: a systematic review in accordance with the PRISMA criteria

OBJECTIVE

To interpret the current evidence on the prevalence of neurodevelopmental disorders (NDDs) through a systematic review based on both DSM-5 (2013) and PRISMA criteria.

METHOD

Empirical studies complying with the PRISMA guidelines were identified from four databases (PubMed, Scopus, Science Direct, and ProQuest) and systematically reviewed. In total, 17 articles were selected for the study.

RESULTS

In the scientific literature, there have been only a few studies measuring the prevalence of NDDs according to the DSM-5 (2013) criteria in people under 18 years old. The reported prevalence rates were as follows: intellectual disability (ID), 0.63%; attention-deficit/hyperactivity disorder (ADHD), 5-11%; autism spectrum disorder (ASD), 0.70-3%; specific learning disorder (SLD), 3-10%; communication disorders (CDs), 1-3.42%; and motor disorders (MDs), 0.76-17%. Although there is extensive literature on specific disorders, NDDs have rarely been assessed as a whole. All of the reviewed studies support the idea that such disorders can be considered chronic, heterogeneous, underdiagnosed conditions and that comorbidity of multiple NDDs is the norm. Likewise, it is estimated that the prevalence of the most studied disorders, such as ADHD, ASD and SLD, remains stable over time and is consistent in different cultures, ages, ethnicities and sexes.

CONCLUSION

The studies reviewed lead us to conclude that the prevalence rate of NDDs fluctuates globally between 4.70 and 88.50%; these variations depend on methodological aspects such as estimation procedures, as well as on sociocontextual phenomena. It is also important to consider that the prevalence found is probably highly influenced by the activity of the countries in the diagnosis and training of professionals who care for children and adolescents. Hence, there is a need for a secondary intervention in the fields of public health and education to minimize socioemotional consequences, prevent academic failure, and reduce the economic cost to society.

The Cognitive Profile of Math Difficulties: A Meta-Analysis Based on Clinical Criteria

Math difficulties (MD) manifest across various domain-specific and domain-general abilities. However, the existing cognitive profile of MD is incomplete and thus not applicable in typical settings such as schools or clinics. So far, no review has applied inclusion criteria according to DSM or ICD, summarized domain-specific abilities or examined the validity of response time scores for MD identification. Based upon stringent clinical criteria, the current meta-analysis included 34 studies which compared cognitive performances of a group with MD (n = 680) and a group without MD (n = 1565). Criteria according to DSM and ICD were applied to identify MD (percentile rank ≤ 16, age range 8–12 years, no comorbidities/low IQ). Effect sizes for 22 abilities were estimated and separated by their level and type of scoring (AC = accuracy, RT = response time). A cognitive profile of MD was identified, characterized by distinct weaknesses in: (a) computation (calculation [AC], fact retrieval [AC]), (b) number sense (quantity processing [AC], quantity-number linking [RT], numerical relations [AC]), and (c) visual-spatial short-term storage [AC]. No particular strength was found. Severity of MD, group differences in reading performance and IQ did not significantly moderate the results. Further analyses revealed that (a) effects are larger when dealing with numbers or number words than with quantities, (b) MD is not accompanied by any weakness in abilities typically assigned to reading, and (c) weaknesses in visual-spatial short-term storage emphasize the notion that number and space are interlinked. The need for high-quality studies investigating domain-general abilities is discussed.

Working memory and arithmetic impairments in children with FMR1 premutation and gray zone alleles

Expansive mutations in familial mental retardation 1 (FMR1) gene have been associated with different phenotypes. Full mutations are associated with intellectual disability and autism spectrum disorder; premutations are associated with math learning difficulties and working memory impairments. In gray zone, neuropsychological development has not yet been described.

Objectives

This study aimed to describe the frequency of FMR1 premutation and gray zone alleles in a school population sample representing a broad spectrum of variation in math achievement and detail school achievement and cognitive performance in the children identified with FMR1 premutation or gray zone alleles.

Methods

We described a two-phase study. In the first phase, 2,195 school-age children were screened for math achievement. In the second phase, 378 children with normal intelligence were neuropsychologically assessed and genotyped for FMR1. Of these, 121 children (61 girls) performed below percentile 25 in mathematics (MD group) and 257 children (146 girls) performed above percentile 25 (control group).

Results

Four pupils presented expanded alleles, one premutation and three gray zone alleles. The girl with the premutation and one boy with a gray zone allele presented impairments in working memory and arithmetic performance below percentile 6, compatible with the diagnosis of developmental dyscalculia. These children's difficulties were not associated with inaccuracy of nonsymbolic number representations or literacy impairments. Dyscalculia in these children seems to be associated mainly with working memory impairments.

Conclusions

FMR1 expansions in the gray zone may contribute to dyscalculia in otherwise healthy and normally intelligent children.

The prevalence of the academic learning difficulties: An observation tool

This study seeks to develop an effective observation tool to determine the prevalence of various academic learning difficulties among school students at the primary level in Sana'a City, Yemen. A measure comprising of 34 items has been processed by the EFA and CFA for contriving ALD's psychometric properties. The study sample comprised 714 students between 6 - 14 years of age. The study's findings revealed that the observation tool under development could measure the prevalence of various academic learning difficulties to a great extent with accuracy. The learning difficulties were classified under five categories based on observation scores. The observed raw scores were standardised after taking the standard deviation from the sample's mean value into consideration. The study's findings suggested that the gender and grade of the subjects affected academic learning difficulties significantly. A brief discussion of the educational implications of these findings has also been presented.

Cognitive Profiles in the WISC-V of Children with ADHD and Specific Learning Disorders

Attention Deficit Hyperactivity Disorder (ADHD) has a high comorbidity with specific learning disorders (SLD). Children with ADHD and children with SLD show specific cognitive deficits. This study aims to examine similarities and differences between cognitive profiles of children with ADHD + SLD, children with SLD only, and a control group to find out whether specific or shared deficits can be identified for the groups. We compared the WISC-V profiles of 62 children with ADHD and SLD (19 girls, M-age = 10.44; SD = 2.44), 35 children with SLD (13 girls, M-age = 10.21; SD = 2.11) and 62 control children without ADHD or SLD (19 girls, M-age = 10.42; SD = 2.39). The ADHD + SLD group performed worse than the control group in the WISC-V indices WMI, PSI, FSIQ, AWMI, CPI and worse than the SLD group in these indices and the VCI, NVI and GAI. Therefore, compared to children with SLD, children with ADHD + SLD did not show specific impairments in any particular cognitive domain but rather non-specific impairment in almost all indices. Hence, the WISC-V is suited to depict the cognitive strength and weaknesses of an individual child as a basis for targeted intervention.

Reading and comprehension: phoniatric assessment in students with reading difficulties

INTRODUCTION

Reading is a highly refined skill that encompasses two main components: decoding graphic symbols and understanding the written message. These aspects generally develop together, but reading comprehension is a much more complex process, sustained not only by the identification of written words and vocabulary but also by language systems, such as syntax and general knowledge. Although there is a well-established technique for performing the phoniatric assessment, there is no common use of tests that assess reading comprehension or the association of this information with other assessment data.

OBJECTIVE

The objective of this study is, in the context of the phoniatric consultation, to evaluate the reading and retelling in children with relevant reading difficulties and to correlate the decoding and comprehension problems with the alterations observed in auditory and visual perceptual tests, pointing out the evidence that best contributed to the differential diagnosis of these subjects.

METHODS

Starting from a population of 301 children enrolled in the 4th and 5th grades of elementary school, 13 children with evident reading and writing difficulties were evaluated regarding the reading and retelling tasks and separated into groups according to the problem of decoding, fluency, and comprehension. Reading performance was correlated with the performance in visual and auditory perceptual tests and based on the similarity analysis, the tests considered to be the most relevant in the diagnosis process of these children were identified.

RESULT

The results suggest that the tasks: naming of figures, repetition of numbers in reverse order, figure copying, syllabic synthesis, phonemic synthesis, rhyme, and phonemic manipulation altogether contribute to diagnosis and multidisciplinary intervention aspects.

CONCLUSION

Some tasks are more relevant to the diagnostic process of children with complaints of learning difficulties in reading.

The quandary of diagnosing mathematical difficulties in a generally low performing population

Brazilian students' mathematical achievement was repeatedly observed to fall below average levels of mathematical attainment in international studies such as PISA.

Objective

In this article, we argue that this general low level of mathematical attainment may interfere with the diagnosis of developmental dyscalculia when a psychometric criterion is used establishing an arbitrary cut-off (e.g., performance<percentile 10) may result in misleading diagnoses.

Methods

Therefore, the present study evaluated the performance of 706 Brazilian school children from 3^rd to 5^th grades on basic arithmetic operations addition, subtraction, and multiplication.

Results

In line with PISA results, children presented difficulties in all arithmetic operations investigated. Even after five years of formal schooling, less than half of 5^th graders performed perfectly on simple addition, subtraction, or multiplication problems.

Conclusions

As such, these data substantiate the argument that the sole use of a psychometric criterion might not be sensible to diagnose dyscalculia in the context of a generally low performing population, such as Brazilian children of our sample. When the majority of children perform poorly on the task at hand, it is hard to distinguish atypical from typical numerical development. As such, other diagnostic approaches, such as Response to Intervention, might be more suitable in such a context.

Rise Time Perception, Phonological Processing, and Reading in Brazilian Portuguese-Speaking Schoolchildren

BACKGROUND/AIMS

Studies of people with dyslexia have pointed to the ability to perceive the amplitude envelope rise time ("beat" perception) as a possible cause of phonological processing (PhP) difficulties in this population. However, there are very few studies about the relationships between such skills in the non-dyslexic school population.

METHODS

We investigated the influence of the beat perception ability on PhP and reading skills of 93 Brazilian Portuguese-speaking schoolchildren from the 3rd to the 5th year, with data on reading, phonological awareness (PhA), lexical access, phonological operational memory, and perception of amplitude envelope rise time. To verify the possible effects of age, gender, and school grade on the tasks in the study, we directly included these variables in the models.

RESULTS

Modeling structural equations showed that beat perception did not influence PhP or reading skills, but only the tasks of repetition of words and pseudowords. These tasks may be related because of the demand for phonological working memory necessary to perform the beat perception task rather than a possible connection between this and phonological abilities, as reported in the literature.

CONCLUSION

We suspect beat perception could be of relevance only for subjects with altered reading and/or a deficit in PhP. Further studies will indicate whether the rise time of the amplitude envelope is an essential acoustic clue only for those individuals whose PhA ability is not fully present.

Effects of transcranial stimulation in developmental neurocognitive disorders: A critical appraisal

Non-invasive brain stimulation (NIBS) has been highlighted as a powerful tool to promote neuroplasticity, and an attractive approach to support cognitive remediation. Here we provide a systematic review of 26 papers using NIBS to ameliorate cognitive dysfunctions in three prevalent neurodevelopmental disorders: Attention-Deficit/Hyperactivity Disorder (ADHD), Developmental Dyslexia and Developmental Dyscalculia. An overview of the state of research shows a predominance of studies using repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) techniques, and an unequal distribution among clinical conditions. Regarding the utility of NIBS, the results are promising but also ambiguous. Twenty-three papers reported beneficial effects, but many of these effects were found only once or were only partially replicated and some studies even reported detrimental effects. Furthermore, most studies differed in at least one core aspect, the NIBS applied, the questionnaires and cognitive tests conducted, or the age group investigated, and sample sizes were mostly small. Hence, further studies are needed to rigorously examine the potential of NIBS in the remediation of cognitive functions. Finally, we discuss potential caveats and future directions. We reason that if adequately addressing these challenges NIBS can be feasible, with potential benefits in treating neurodevelopmental disorders.

The 100 Top-Cited Studies on Dyslexia Research: A Bibliometric Analysis

Background: Citation analysis is a type of quantitative and bibliometric analytic method designed to rank papers based on their citation counts. Over the last few decades, the research on dyslexia has made some progress which helps us to assess this disease, but a citation analysis on dyslexia that reflects these advances is lacking. Methods: A retrospective bibliometric analysis was performed using the Web of Science Core Collection database. The 100 top-cited studies on dyslexia were retrieved after reviewing abstracts or full-texts to May 20th, 2021. Data from the 100 top-cited studies were subsequently extracted and analyzed. Results: The 100 top-cited studies on dyslexia were cited between 245 to 1,456 times, with a median citation count of 345. These studies were published in 50 different journals, with the "Proceedings of the National Academy of Sciences of the United States of America" having published the most (n = 10). The studies were published between 1973 and 2012 and the most prolific year in terms of number of publications was 2000. Eleven countries contributed to the 100 top-cited studies, and nearly 75% articles were either from the USA (n = 53) or United Kingdom (n = 21). Eighteen researchers published at least two different studies of the 100 top-cited list as the first author. Furthermore, 71 studies were published as an original research article, 28 studies were review articles, and one study was published as an editorial material. Finally, "Psychology" was the most frequent study category. Conclusions: This analysis provides a better understanding on dyslexia and may help doctors, researchers, and stakeholders to achieve a more comprehensive understanding of classic studies, new discoveries, and trends regarding this research field, thus promoting ideas for future investigation.

[Intelligence structure and clinical features of school-age children with attention deficit hyperactivity disorder and specific learning disorder]

OBJECTIVE

To study the intelligence structure and clinical features of children with attention deficit hyperactivity disorder (ADHD) and specific learning disorder (SLD).

METHODS

A retrospective analysis was performed on 88 school-age children with ADHD. According to the presence or absence of SLD, they were divided into two groups: simple ADHD group with 45 children and ADHD+SLD group with 43 children. Intelligence structure and clinical features were compared between the two groups.

RESULTS

Compared with the simple ADHD group, the ADHD+SLD group had significantly lower verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), and full intelligence quotient (FIQ) (P<0.05), significantly lower scores of VIQ factors (including information, similarities, arithmetic, and recitation) (P<0.05), and significantly lower scores of PIQ factors (including picture completion, picture arrangement, block design, and object assembly) (P<0.05). The development of SLD was negatively correlated with FIQ, VIQ, and PIQ. It was also negatively correlated with the scores of intelligence structure factors (including information, similarities, arithmetic, recitation, picture completion, picture arrangement, block design, and object assembly) (P<0.05).

CONCLUSIONS

Children with ADHD and SLD have poorer FIQ, VIQ, and PIQ than those with ADHD alone, which mainly manifests as the weak abilities of most intelligence structure factors. It is necessary to pay attention to the management and intervention of SLD in school-age children with ADHD.

The effects of sex on prevalence and mechanisms underlying neurodevelopmental disorders

Neurodevelopmental disorders occur more frequently in boys than in girls and often differ in presentation between the sexes. The sex differences in prevalence and presentation of autism spectrum disorder, intellectual disability, communication disorders, specific learning disabilities, attention deficit/hyperactivity disorder, Tourette's syndrome, and epilepsy are discussed, as well as sex differences in the patterns of comorbidities between these disorders. Prominent theories have been proposed to explain sex biases. These include genetic factors, sex hormones, sociological factors, cognitive differences between the sexes, and environmental insult. Despite the large body of research reviewed in this chapter, many aspects of sex-related effects in neurodevelopmental disorders remain poorly understood.

Associations between Learning and Behavioral Difficulties in Second-Grade Children

Learning and behavioral difficulties often emerge during the first years of primary school and are one of the most important issues of concern for families and schools. The study was aimed at investigating the co-occurrence of difficulties between academic learning and emotional-behavioral control in typically developing school children and the moderating role of sex. A sample of 640 second-grade school children participated in the study. This study used the Strengths and Difficulties Questionnaire to measure the emotional and behavioral difficulties and a battery of objective and standardized tests to evaluate the learning skills in children. In this sample 7% to 16% of children performed below the normal range in reading and/or arithmetic tests. Mixed models showed that children’s hyperactive behaviors were positively related to both reading and math difficulties, and emotional problems correlated negatively with reading accuracy. The more children displayed behavioral difficulties, the more they were exposed to the risk of worsening reading and math performance, especially for girls. The result that among different emotional-behavioral problems within the school setting, hyperactivity behaviors and emotional difficulties are related to learning difficulties with a moderate effect of sex, needs to be taken into account in screening and prevention programs for learning difficulties in order to not disregard the complexity of the associated profiles.

The prevalence and comorbidity rates of specific learning disorder among primary school children in Turkey

Purpose: The aim of the present study was to investigate the prevalence of specific learning disorder (SLD), comorbid disorders, and risk factors in primary school children for the first time in two-stage design in Turkey.Materials and methods: Participants were 1041 pupils in 28 primary schools and aged from 7 to 11. The Mathematics, Reading, Writing Assessment Scale (MOYA) teacher and parent forms were used in the screening stage and parents and teachers of each child completed MOYA. Ninety-five children were screen positive and eighty-three of these children participated in the interview. SLD diagnoses were based on DSM V criteria. Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL) was used for the comorbid psychiatric disorders.Results and conclusions: The prevalence rate of the SLD was 6.6%, impairment in reading was 4%, in mathematics was 3.6%, and in written expression was 1.8%. About 62.75% of children with SLD had one or more comorbid diagnoses. ADHD was the most common comorbid mental disorder in SLD (54.9%). SLD prevalence was higher among males. The prevalence of SLD in primary school children in Turkey is consistent with previous studies.

Self-reported specific learning disorders and risk factors among Hungarian adolescents with functional abdominal pain disorders: a cross sectional study

BACKGROUND

Despite its increasing clinical significance and diagnostic challenges, little is known about functional abdominal pain disorders (FAPDs) in Central-Eastern Europe. In this paper, the prevalence and potential sociodemographic correlates of FAPDs among Hungarian adolescents are explored.

METHODS

A cross-sectional, nationwide, questionnaire study in a representative sample of 657 adolescents has been conducted. With a response rate of 80.2%, 522/527 (99.1%) questionnaires were eligible for data analysis (N = 267, 51.1% girls, mean age 14.8, SD 2.4 years). The questionnaire included sociodemographic variables (age, sex, place of residence, marital status of the parents, family income, religion, educational level of parents), questions regarding self-reported specific learning disorders and the Questionnaire for Paediatric Gastrointestinal Symptoms Rome ΙΙΙ Edition.

RESULTS

The prevalence of FAPDs was 11.9% (N = 62). FAPDs were significantly associated with female sex. Living in a county town showed a negative correlation with FAPD. Adolescents with self-reported arithmetic learning disorders had an 8.7-fold likelihood of FAPD (OR, 8.7; 95% CI (3.5-21.9). Adolescent girls reported pain in all subtypes of FAPDs more frequently than adolescent boys except functional abdominal pain syndrome. The most prevalent FAPD was abdominal migraine (N = 32, 6.1%), followed by irritable bowel syndrome (N = 24, 4.6%).

CONCLUSIONS

The prevalence of FAPDs in Hungary is similar to that reported worldwide, however, contrary to international data, abdominal migraine is the most frequently encountered FAPD in Hungary. In addition to well-known correlates of FAPDs, such as female sex and place of residence, arithmetic learning disorders have also been identified as correlating with the prevalence of FAPDs. Our results suggest culture-specific differences in the distribution of FAPDs, and confirm the significance of school performance indicators such as specific learning disorders as a correlate of FAPDs.

ADHD Is Comorbid to Migraine in Childhood: A Population-Based Study

Objective: Recurrent headaches and ADHD are prevalent in the pediatric population. Herein, we assess if ADHD is comorbid to headaches overall, to headache subtypes (e.g., migraine), and to headache frequency. Method: Informed consent and analyzable data were obtained for 5,671 children aged 5 to 12 years (65.9% of the target sample). Parents and teachers were interviewed using validated questionnaires based on the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5). Relative risks were modeled using univariate and multivariate analyses. Results: As contrasted to nonheadache controls, the prevalence of ADHD was significantly higher in children with migraine (p < .001) but not in those with tension-type headaches. In children with migraine, risk of ADHD increased as a function of headache frequency (p < .05). Conclusion: Migraine and frequent migraine are comorbid to ADHD. Future studies should focus on the impact of the association on the burden to the children and their families.

An Epidemiological Study of Chinese Children with Developmental Dyslexia

OBJECTIVE

The epidemiological studies of Chinese developmental dyslexia (DD) in China are still limited. The current study aimed to investigate the prevalence rate, risk factors, and psychiatric comorbidities of Chinese DD in Guangzhou, a city in South China.

METHOD

A total of 1661 students from second to fifth grades were recruited. The dyslexic students were identified by evaluating learning disability through the Pupil Rating Scale-Revised Screening for Learning Disability (PRS) scale by the head teachers and word recognition through the standard test. Students with a PRS score of <65 received the Raven's test, and those with intelligence quotient scores below 80 in the Raven's test were excluded. Psychiatric comorbidities were assessed by the Strength and Difficulties Questionnaire completed by parents.

RESULTS

The prevalence rate of Chinese DD was 4.9% in Guangzhou city. There were significant differences in gender, the paternal educational level, and reading experience before the age of 6 years between the DD group and the non-DD group. Male gender (odds ratio [OR] = 4.17), low paternal educational level (p = 0.045), and lack of reading experience before the age of 6 years (OR = 1.99) were the risk factors for DD. The DD cases had a higher risk of hyperactivity and inattention (OR = 3.21).

CONCLUSION

This study showed that the prevalence rate of DD was 4.9% in Guangzhou city. Male gender, low paternal educational level, and lack of reading experience before the age of 6 years were the risk factors for Chinese DD. The high comorbidity rate of hyperactivity and inattention in the Chinese DD population needs further evaluation.

Persistent Effects of Musical Training on Mathematical Skills of Children With Developmental Dyscalculia

Musical training (MT) is perceived as a multi-sensory program that simultaneously integrates visual, aural, oral, and kinesthetic senses. Furthermore, MT stimulates cognitive functions in a ludic way instead of tapping straight into the traditional context of school learning, including mathematics. Nevertheless, the efficacy of MT over mathematics remains understudied, especially concerning longstanding effects. For this reason, this longitudinal study explored the impact of MT on numerical cognition and abstract visual reasoning using a double-blind and quasi-experimental design. We assessed two groups of children from primary schools, namely one with developmental dyscalculia [DD; n = 22] and another comprising typically developing children [TD; n = 22], who concomitantly underwent MT. Numerical cognition measurement was carried out at four different time points: Baseline (pre-MT assessment), mid-test (after 7 weeks of MT), post-test (after 14 weeks of MT), and follow-up (10 weeks after the end of MT). Significant interactions were found between time and group for numerical cognition performance, in which the DD group showed higher scores in number comprehension, number production at mid-test, and calculation at post-test compared to baseline. A key finding was that number production, number comprehension, and calculation effects were time-resistant for the DD group since changes remained on follow-up. Moreover, no significant differences over time were found for abstract visual reasoning for both groups. In conclusion, the findings of this study showed that MT appears to be a useful tool for compensatory remediation of DD.

Comorbidities Between Specific Learning Disorders and Psychopathology in Elementary School Children in Germany

Children with reading and/or spelling disorders have increased rates of behavioral and emotional problems and combinations of these. Some studies also find increased rates of attention-deficit/hyperactivity disorder (ADHD), conduct disorder, anxiety disorder, and depression. However, the comorbidities of, e.g., arithmetic disorders with ADHD, anxiety disorder, and depression have been addressed only rarely. The current study explored the probability of children with specific learning disorders (SLD) in reading, spelling, and/or arithmetic to also have anxiety disorder, depression, ADHD, and/or conduct disorder. The sample consisted of 3,014 German children from grades 3 and 4 (mean age 9;9 years) who completed tests assessing reading, spelling as well as arithmetic achievement and intelligence via a web-based application. Psychopathology was assessed using questionnaires filled in by the parents. In children with a SLD we found high rates of anxiety disorder (21%), depression (28%), ADHD (28%), and conduct disorder (22%). Children with SLD in multiple learning domains had a higher risk for psychopathology and had a broader spectrum of psychopathology than children with an isolated SLD. The results highlight the importance of screening for and diagnosing psychiatric comorbidities in children with SLD.

The Child Evaluation Checklist (CHECK): A Screening Questionnaire for Detecting Daily Functional "Red Flags" of Underrecognized Neurodevelopmental Disorders among Preschool Children

Background

Early identification of invisible comorbid neurodevelopmental disorders, such as specific learning disorders, attention deficit hyperactive disorders, and developmental coordination disorders, is crucial to improving children's daily functional deficits related to executive functions. However, a practical questionnaire to address parents' concerns is lacking.

Aims

To develop a reliable and valid assessment tool that can identify young children at risk for invisible underrecognized neurodevelopmental disorders. This article describes the development and standardization of the Child Evaluation Checklist (CHECK).

Methods and Procedures

Participants were 186 children aged 3 to 6 years: 91 with suspected invisible neurodevelopmental disorders, and 95 controls with typical development. Parents completed a demographic questionnaire, the CHECK, and the Behavior Rating Inventory of Executive Function-Preschool Version (BRIEF-P).

Outcomes and Results

The CHECK's construct validity indicated high internal consistency for each part (Part A: α = .94; Part B: α = .90) and moderate-to-high consistency for each of Part A's four factors. Significant correlations, as well as significant group differences, were found between the CHECK factors and BRIEF-P scores.

Conclusions and Implications

Use of the CHECK allows for timely identification of suspicious ("red flags") invisible neurodevelopmental disorders. It may support parents' sufficient awareness and knowledge to refer their children for comprehensive evaluation and intervention.

The Diagnosis and Treatment of Dyscalculia

BACKGROUND

3-7% of all children, adolescents, and adults suffer from dyscalculia. Severe, persistent difficulty performing arithmetical calculations leads to marked impairment in school, at work, and in everyday life and elevates the risk of comorbid mental disorders. The state of the evidence underlying various methods of diagnosing and treating this condition is unclear.

METHODS

Systematic literature searches were carried out from April 2015 to June 2016 in the PsycInfo, PSYNDEX, MEDLINE, ProQuest, ERIC, Cochrane Library, ICTRP, and MathEduc databases. The main search terms on dyscalculia were the German terms "Rechenstörung," "Rechenschwäche," and "Dyskalkulie" and the English terms "dyscalculia," "math disorder, and "math disability." The data from the retrieved studies were evaluated in a meta-analysis, and corresponding recommendations on the diagnosis and treatment of dyscalculia were jointly issued by the 20 societies and associations that participated in the creation of this guideline.

RESULTS

The diagnosis of dyscalculia should only be made if the person in question displays below-average mathematical performance when seen in the context of relevant information from the individual history, test findings, clinical examination, and further psychosocial assessment. The treatment should be directed toward the individual mathematical problem areas. The mean effect size found across all intervention trials was 0.52 (95% confidence interval [0.42; 0.62]). Treatment should be initiated early on in the primary-school years and carried out by trained specialists in an individual setting; comorbid symptoms and disorders should also receive attention. Persons with dyscalculia are at elevated risk of having dyslexia as well (odds ratio [OR]: 12.25); the same holds for attention deficit/hyperactivity disorder and for other mental disorders, both internalizing (such as anxiety and depression) and externalizing (e.g., disorders characterized by aggression and rule-breaking).

CONCLUSION

Symptom-specific interventions involving the training of specific mathematical content yield the best results. There is still a need for high-quality intervention trials and for suitable tests and learning programs for older adolescents and adults.

Distinct effects of visual and auditory temporal processing training on reading and reading-related abilities in Chinese children with dyslexia

This study aimed to examine the effects of temporal processing training on the reading abilities of Chinese children with dyslexia. In total, 69 Chinese children with dyslexia in grades three through six were recruited in Taiwan. The children were divided into the following three equal groups: (1) auditory temporal processing training group, (2) visual temporal processing training group, and (3) control group with no specific training. The participants in both training groups received instruction with identical durations (30-40 min), intensities (12 times in total), and frequencies (three to four times per week). The participants in the control group were asked to independently surf some specified websites using devices similar to those used by the two experimental groups for an identical duration, intensity, and frequency. Our results indicated that the two groups who received temporal processing training exhibited significant correlations among Chinese character reading, rapid naming, and corresponding reading-related abilities, while visual temporal processing served as a significant predictor of Chinese character reading ability even if all background data, reading-related abilities, and auditory temporal processing were introduced first. Additionally, significant interactions were found between the Groups and Tested sessions in all the measures, except for phonological awareness, confirming the distinct effects of different temporal processing on most measures involved in this study. Further simple main effects revealed that only those who received the visual temporal processing training gained benefits in the corresponding reading-related ability (i.e., orthographic knowledge) and far-transfer to Chinese character reading.

Assessment of Psychiatric Comorbidity and WISC-R Profiles in Cases Diagnosed with Specific Learning Disorder According to DSM-5 Criteria

Introduction

In this study, the frequency of psychiatric comorbidity in children and adolescents who were diagnosed with specific learning disorder, the factors that affect the frequency of comorbidity, the subtypes of specific learning disorder and the effects on cognitive profile have been investigated.

Methods

Our study was performed among 80 cases with the age range 6-15 years who diagnosed with specific learning disorder Child and Adolescent Psychiatry Department between January and June 2015. In the study, DSM-IV Based Screening and Evaluation Scale for Child and Adolescent Behavioral Disorders, Specific Learning Disability Evaluation Scale and the WISC-R test were performed. During the interview, reading-writing-math abilities evaluation list (error analysis) was performed in order to define the specific learning disorder subgroup and to evaluate the detailed error profile of the specific learning disorder subgroup. Kiddie Schedule for Affective Disorders and Schizophrenia for School-age Children-Present and Lifetime Turkish Version (KSADS) was performed to detect psychiatric comorbidity diagnoses.

Results

92.5% of the cases have a comorbid psychiatric disorder. The most frequent psychiatric comorbidity was attention deficit hyperactivity disorder (82.3%), followed by specific phobia (46.3%), oppositional defiant disorder (26.3%), enuresis (25%) and tic disorders (22.5%). Psychiatric comorbidity is detected more often in patients with specific learning disorder accompanied by attention deficit and hyperactivity disorder. The most frequent subtype of specific learning disorder is combined type disorder consisting of reading, writing and math disorder (37.5%). The WISC-R score of the patients who had math disorder were found to be lower than the others, and also it was detected that they learned reading and writing later, and have more comorbid psychiatric disorders.

Conclusion

The results of our study indicate that associated psychiatric disorders are frequent with specific learning disorder. Specific learning disorder should not be considered as a single disorder, but should be assessed and treated with comorbid psychiatric disorders.

The prevalence of specific learning disorder in mathematics and comorbidity with other developmental disorders in primary school-age children

Mathematics difficulties are common in both children and adults, and they can have a great impact on people's lives. A specific learning disorder in mathematics (SLDM or developmental dyscalculia) is a special case of persistent mathematics difficulties, where the problems with maths cannot be attributed to environmental factors, intellectual disability, or mental, neurological or physical disorders. The aim of the current study was to estimate the prevalence rate of SLDM, any gender differences in SLDM, and the most common comorbid conditions. The DSM-5 provides details regarding these only for specific learning disorders in general, but not specifically for SLDM. We also compared the prevalence rates obtained on the basis of the DSM-IV and DSM-5 criteria. We investigated the performance of 2,421 primary school children on standardized tests of mathematics, English, and IQ, and several demographic factors over the primary school years. We applied the DSM-5 diagnostic criteria to identify children with a potential diagnosis of SLDM. Six per cent of our sample had persistent, severe difficulties with mathematics, and, after applying the exclusion criteria, 5.7% were identified as having an SLDM profile. Both persistent maths difficulties and consistently exceptionally high performance in maths were equally common in males and females. About half of the children with an SLDM profile had some form of language or communication difficulty. Some of these children also had a diagnosis of autism, social, emotional, and behavioural difficulties or attention deficit and hyperactivity disorder. Our findings have important implications for research and intervention purposes, which we discuss in the study.

Characterization of two familial cases presenting with a syndromic specific learning disorder and carrying (17q;21q) unbalanced translocations

Chromosomal microarray (CMA) can detect pathogenic copy number variations in 15–20% of individuals with intellectual disability and in 10% of patients with autism spectrum disorders. The diagnostic rate in specific learning disorders (SLD) is unknown. Our study emphasizes the usefulness of CMA in the diagnostic workout assessment of familial SLD.

Early vulnerabilities for psychiatric disorders in elementary schoolchildren from four Brazilian regions

PURPOSE

The purpose of the study is to identify early vulnerabilities for psychiatric disorders among Brazilian elementary school children, controlling for familial and community adversities.

METHODS

This is a cross-sectional study examining the association between child psychiatric disorders and potential early vulnerabilities (disability, low intellectual quotient, and negative dimensions of the temperament trait self-directedness (low resourcefulness, low purposefulness, low enlightened second nature), controlling for the potential confounders: familial and community adversities.

SAMPLE

Four probabilistic samples of second-to-sixth grade students from public schools in four towns from different Brazilian regions (N = 1620). The following instruments were applied: the K-SADS-PL (to assess child/adolescent psychiatric disorders); the Ten-Question Screen (to measure child disability); three structured questions used as proxy of self-directedness; and the reduced version of the WISC-III to measure IQ. To evaluate familial/community adversities: Self-Report Questionnaire-SRQ-20 (to assess maternal/primary caretaker anxiety/depression); questions derived from structured questionnaires (to measure child abuse, marital physical violence, neighborhood violence); Brazilian Association of Research Companies questionnaire (to evaluate poverty/socioeconomic status). Trained psychologists interviewed mothers/primary caretakers and evaluated children/adolescents individually.

RESULTS

A final logistic regression model showed that children/adolescents with low resourcefulness, low purposefulness, low enlightened second nature, lower IQ and disability were more likely to present any child psychiatric disorders.

CONCLUSION

Early vulnerabilities such as low IQ, presence of disability, and dimensions of temperament were associated with psychiatric disorders among Brazilian elementary school children, after controlling for familial and ecological confounders. These early vulnerabilities should be considered in mental health prevention/intervention programs in low-middle-income countries like Brazil.

Reading and Writing Skills in Children With Specific Learning Disabilities With and Without Developmental Coordination Disorder

This pilot study is to investigate the influence of a developmental coordination disorder (DCD) comorbidity in a group of children with learning disability (LD). Reading and writing were assessed to investigate if the coexistence of a motor impairment can worsen writing quality, speed, and reading accuracy. A sample of 33 LD children (aged 7-11 years) was divided in two subgroups, on the base of their scores on the Movement Assessment Battery for Children: LD-only (n = 14) and LD with a comorbidity for DCD (LD-DCD, n = 19). No differences were found in handwriting speed, but significant differences were found in handwriting quality: LD-DCD children showed a worst performance. Reading words and nonwords accuracy was more impaired in LD-only children than in LD-DCD children. Group differences suggest a poorer phonological decoding of the LD-only sample, whereas worst cursive handwriting legibility scores are typical of the motor-impaired subgroup.

Cortical responses to tone and phoneme mismatch as a predictor of dyslexia? A systematic review

Evidence from event-related-potential (ERP) studies has repeatedly shown differences in the perception and processing of auditory stimuli in children with dyslexia compared to control children. The mismatch negativity (MMN) - an ERP component reflecting passive auditory change detection ability - has been found to be reduced, not only in children with a diagnosis of dyslexia, but also in infants and preschool children at risk of developing dyslexia. However, the results are controversial due to the different methods, age of the children and stimuli used. The aim of the present review is to summarize and evaluate the MMN research about at-risk children in order to identify risk factors that discriminate between children with and without dyslexia risk and to analyze if the MMR (the abbreviation refers to positive and negative mismatch responses) correlates with later reading and spelling ability. A literature search yielded 17 studies reporting MMR to speech or non-speech stimuli in children at risk of dyslexia. The results of the studies were inconsistent. Studies measuring speech MMR often found attenuated amplitudes in the at-risk group, but mainly in very young children. The results for older children (6-7years) and for non-speech stimuli are more heterogeneous. A moderate positive correlation of MMR amplitude size with later reading and spelling abilities was consistently found. Overall, the findings of this review indicate that the MMR can be a valuable part of early dyslexia identification, which can enable efficient support and intervention for a child before the first problems appear.

The Probable Prevalence and Sociodemographic Characteristics of Specific Learning Disorder in Primary School Children in Edirne

Introduction

The aim of this study was to research the probable prevalence of Specific Learning Disorder (SLD) in primary school children in Edirne City and the relationships with their sociodemographic characteristics.

Methods

The sample of our study was composed of 2,174 children who were educated in primary schools in second, third, and fourth grades in the academic year 2013-2014 in Edirne City. The teachers and parents of these children were given Specific Learning Difficulties Symptom Scale, Learning Disabilities Symptoms Checklist (teacher and parent forms), and sociodemographic data forms to fill in. Binary logistic regression analysis was used to assess the risk factors for SLD.

Results

Our study revealed that the probable prevalence of SLD was 13.6%; 17% for boys and 10.4% for girls. Reading impairment was 3.6%, writing impairment was 6.9%, and mathematic impairment was 6.5%. We determined that consanguineous marriages, low income, history of neonatal jaundice were found as risks for SLD; born by caesarean, developmental delay of walking, and history of neonatal jaundice were found as risks for mathematic impairment. A history of learning difficulties of parents was a risk factor for forming SLD and subtypes.

Conclusion

Our findings were consistent with other study results about the prevalence of SLD. The relationships between the probable prevalence rates and sociodemographic data were discussed.

Does the late positive component reflect successful reading acquisition? A longitudinal ERP study

Developmental dyslexia is a reading disorder that is associated with deficits in phonological processing, where the exact neural basis for those processing deficits remains unclear. In particular, disagreement exists whether degraded phonological representations or an impaired access to the phonological representations causes these deficits. To investigate this question and to trace changes in neurophysiology during the process of reading acquisition, we designed a longitudinal study with event related potentials (ERPs) in children between kindergarten and second grade. We used an explicit word processing task to elicit the late positive component (LPC), which has been shown to reflect phonological processing. A brain-wide analysis of the LPC with an electrode-wise application of mixed effects models showed significantly attenuated amplitudes in the left temporo-parietal region in dyslexic children. Since these differences were only present in the word and not in the picture (i.e. control) condition, the attenuated amplitudes might reflect impaired access to the phonological representations of words. This was further confirmed by the longitudinal development, which showed a rapid increase in amplitude at the beginning of reading instruction and a decrease with continuing automatization, possibly pointing to a progression from grapheme-phoneme parsing to whole word reading. Our longitudinal study provides the first evidence that it is possible to detect neurophysiological differences in the LPC between children with dyslexia and control children in both preliterate and very early stages of reading acquisition, providing new insights about the neurophysiological development and a potential marker of later reading problems.

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First longitudinal study of the late positive component (LPC)

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Left temporo-parietal LPC differs between control and dyslexic children.

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LPC increase at reading acquisition and decrease with automatization in typical readers.

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Dyslexic children do not show this neurophysiological course of development.

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Findings might indicate an impaired access to phonological representations.

Spoken Word Recognition Enhancement Due to Preceding Synchronized Beats Compared to Unsynchronized or Unrhythmic Beats

The relation between rhythm and language has been investigated over the last decades, with evidence that these share overlapping perceptual mechanisms emerging from several different strands of research. The dynamic Attention Theory posits that neural entrainment to musical rhythm results in synchronized oscillations in attention, enhancing perception of other events occurring at the same rate. In this study, this prediction was tested in 10 year-old children by means of a psychoacoustic speech recognition in babble paradigm. It was hypothesized that rhythm effects evoked via a short isochronous sequence of beats would provide optimal word recognition in babble when beats and word are in sync. We compared speech recognition in babble performance in the presence of isochronous and in sync vs. non-isochronous or out of sync sequence of beats. Results showed that (a) word recognition was the best when rhythm and word were in sync, and (b) the effect was not uniform across syllables and gender of subjects. Our results suggest that pure tone beats affect speech recognition at early levels of sensory or phonemic processing.

[Learning disorders in ADHD: How are they related?]

Learning difficulties in general and learning disabilities in particular are almost constant in attention deficit disorder with or without hyperactivity (ADHD). Despite a major research effort, the extent and diversity of these comorbid events still raise many questions about the exact nature of their pathogenetic condition (simple consequences of ADHD or specific related disorders?) and consequently the best way to support them. This article aims to present a brief review of the current data.

Poor stimulus discriminability as a common neuropsychological deficit between ADHD and reading ability in young children: a moderated mediation model

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is frequently associated with poorer reading ability; however, the specific neuropsychological domains linking this co-occurrence remain unclear. This study evaluates information-processing characteristics as possible neuropsychological links between ADHD symptoms and RA in a community-based sample of children and early adolescents with normal IQ (⩾70).

METHOD

The participants (n = 1857, aged 6-15 years, 47% female) were evaluated for reading ability (reading single words aloud) and information processing [stimulus discriminability in the two-choice reaction-time task estimated using diffusion models]. ADHD symptoms were ascertained through informant (parent) report using the Development and Well-Being Assessment (DAWBA). Verbal working memory (VWM; digit span backwards), visuospatial working memory (VSWM, Corsi Blocks backwards), sex, socioeconomic status, and IQ were included as covariates.

RESULTS

In a moderated mediation model, stimulus discriminability mediated the effect of ADHD on reading ability. This indirect effect was moderated by age such that a larger effect was seen among younger children.

CONCLUSION

The findings support the hypothesis that ADHD and reading ability are linked among young children via a neuropsychological deficit related to stimulus discriminability. Early interventions targeting stimulus discriminability might improve symptoms of inattention/hyperactivity and reading ability.