Search

Proficient reading requires critical phonological processing skill that interacts with both genetic and environmental factors. However, the precise nature of the relationships between phonological processing and genetic and environmental factors are poorly understood. We analyzed data from the Genes, Reading and Dyslexia (GRaD) Study on 1419 children ages 8–15 years from African-American and Hispanic-American family backgrounds living in North America. The analyses showed that phonological awareness mediated the relationship between DCDC2-READ1 and reading outcomes when parental education and socioeconomic status was low. The association between READ1 and reading performance is complex, whereby mediation by phonological awareness was significantly moderated by both parental education and socioeconomic status. These results show the importance of home environment and phonological skills when determining associations between READ1 and reading outcomes. This will be an important consideration in the development of genetic screening for risk of reading disability. [ABSTRACT FROM AUTHOR]

To better understand the implications of comorbidity between reading disability (RD) and attention‐deficit/hyperactivity disorder (ADHD), a sample of 225 participants with RD but 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. Reading disability (RD) is a common childhood disorder that is defined by significant and unexpected underachievement in reading. In addition to specific difficulties in reading, many individuals with RD also meet criteria for at least one other disorder, a phenomenon known as comorbidity. To better understand the implications of comorbidity between RD and attention‐deficit/hyperactivity disorder (ADHD), a sample of 225 participants with RD but 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. Results indicated that RD is associated with elevations of emotional and behavioral symptoms, significant academic and psychosocial difficulties. However, the group with both RD and ADHD was most impaired on most of these 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 executive functions that are most severe in the group with both disorders. 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. [ABSTRACT FROM AUTHOR]

This paper reviews three studies investigating the relationship between brain regions involved in executive control and those involved in reading comprehension in typically‐developing teens. In the first study, three regions of posterior left lateral prefrontal cortex (i.e., precentral gyrus, inferior frontal junction, inferior frontal gyrus) were consistently activated across three task domains: reading comprehension, numerical estimation, and executive processes in working memory, suggesting these regions exert domain‐general executive control. In a second study, brain activity in the precentral gyrus during reading comprehension was found to be associated with individual differences in reading achievement. A subsequent investigation indicated that while all three prefrontal regions exhibit greater connectivity to the angular gyrus during reading comprehension compared to symbol identification, each also exhibits unique connectivity to distinct posterior regions implicated in reading processes. Hence, reading difficulties during adolescence may arise, in part, from difficulties in executive control over processing in language‐related brain regions. This review paper discusses research that examines the degree to which executive processes implemented by prefrontal brain regions are involved during reading comprehension. Three investigations are discussed: one focused on methods for clearly identifying such regions; a second examining the degree to which activation in these areas is associated with individual differences in reading proficiency, and third examining the functional connectivity of these regions with language‐related posterior brain regions. [ABSTRACT FROM AUTHOR]

This study examined whether domain-general cognitive weaknesses in processing speed (PS) or executive functioning (EF) moderate the relation between word reading scores and anxiety such that lower word reading scores in combination with lower cognitive scores are associated with higher anxiety symptoms. The sample consisted of 755 youth ages 8–16 who were recruited as part of the Colorado Learning Disabilities Research Center twins study. Lower scores on PS (R 2 =.007, p =.014), EF (R 2 =.009, p =.006), and word reading (R 2 =.006–.008, p =.010–.032) were associated with higher anxiety scores. In addition, the word reading × cognitive interactions were significant such that lower scores on PS (R 2 =.010, p =.005) or EF (R 2 =.013, p =.010) combined with lower word reading were associated with higher-than-expected anxiety symptoms. Results suggest that weaknesses in PS, EF, and word reading are modestly associated with higher anxiety symptoms, and these anxiety symptoms may be compounded in youth with both PS or EF weaknesses and word reading difficulties. These findings can guide assessment approaches for identifying youth with word reading challenges who may be at increased risk for anxiety. [ABSTRACT FROM AUTHOR]

Genetics researchers increasingly combine data across many sources to increase power and to conduct analyses that cross multiple individual studies. However, there is often a lack of alignment on outcome measures when the same constructs are examined across studies. This inhibits comparison across individual studies and may impact the findings from meta-analysis. Using a well-characterized genotypic (brain-derived neurotrophic factor: BDNF) and phenotypic constructs (working memory and reading comprehension), we employ an approach called Rosetta, which allows for the simultaneous examination of primary studies that employ related but incompletely overlapping data. We examined four studies of BDNF, working memory, and reading comprehension with a combined sample size of 1711 participants. Although the correlation between working memory and reading comprehension over all participants was high, as expected (ρ = 0.45), the correlation between working memory and reading comprehension was attenuated in the BDNF Met/Met genotype group (ρ = 0.18, n.s.) but not in the Val/Val (ρ = 0.44) or Val/Met (ρ = 0.41) groups. These findings indicate that Met/Met carriers may be a unique and robustly defined subgroup in terms of memory and reading comprehension. This study demonstrates the utility of the Rosetta method when examining complex phenotypes across multiple studies, including psychiatric genetic studies, as shown here, and also for the mega-analysis of cohorts generally. [ABSTRACT FROM AUTHOR]

The relationship between the p factor and cognition in youth has largely focused on general cognition (IQ) and executive functions (EF). Another cognitive construct, processing speed (PS), is dissociable from IQ and EF, but has received less research attention despite being related to many different mental health symptoms. The present sample included 795 youth, ages 11–16 from the Colorado Learning Disabilities Research Center (CLDRC) sample. Confirmatory factor analyses tested multiple p factor models, with the primary model being a second-order, multi-reporter p factor. We then tested the correlation between the p factor and a latent PS factor. There was a significant, negative correlation between the p factor and PS (r(87) = -0.42, p <.001), indicating that slower processing speed is associated with higher general mental health symptoms. This association is stronger than previously reported associations with IQ or EF. This finding was robust across models that used different raters (youth and caregiver) and modeling approaches (second-order vs. bifactor). Our findings indicate that PS is related to general psychopathology symptoms. This research points to processing speed as an important transdiagnostic construct that warrants further exploration across development. [ABSTRACT FROM AUTHOR]

Objective: Self-determination theory suggests that the satisfaction and frustration of basic psychological needs--autonomy, competence, relatedness--are uniquely associated with overall well-being. Undergraduates with attentiondeficit/hyperactivity disorder (ADHD) experience more academic-related impairment and are less likely to graduate. Thus, well-being is important to understand and aim to improve in these students. Method: Students at four universities (N = 2,197) completed a survey and reported previous diagnoses, ADHD symptoms, and psychological need satisfaction and frustration. Group differences were explored via t-tests; associations were explored via structural equation modeling. Results: The ADHD group reported lower satisfaction and higher frustration across all psychological needs. Inattention and hyperactivity/impulsivity were uniquely associated with aspects of need fulfillment beyond the impact of comorbid symptoms. Sex differences emerged such that women with ADHD had the lowest overall need satisfaction. Conclusions: Addressing need fulfillment, both satisfaction and frustration, in interventions with undergraduates with clinical/subclinical levels of ADHD may optimize treatment effectiveness. [ABSTRACT FROM AUTHOR]

Previous studies have shown that Attention-Deficit/Hyperactivity disorder (ADHD) is marked by impairments in academic functioning in reading, writing, and mathematics. Yet, virtually no studies have examined academic functioning in terms of both basic skills (e.g., word recognition, handwriting/spelling, arithmetic calculations) and more complex advanced skills (e.g., reading comprehension, writing composition, and mathematical problem-solving) within the same sample. In the present study, 518 children with ADHD were compared to a control group of 851 children without ADHD (ages 8–18) and assessed on a comprehensive battery of reading, writing, and math assessments. It was hypothesized that ADHD diagnostic status would uniquely predict performance on advanced skill measures even after controlling for performance on basic skills in that academic domain. ADHD status was associated with worse performance across all academic tests. Results also indicated that ADHD independently predicted performance for measures of writing composition and one measure of reading comprehension, even after controlling for performance on basic skills in those domains. However, ADHD did not independently predict mathematical problem-solving performance. These findings add to the literature on ADHD and academic functioning and indicate that inattention may weaken skills necessary for effective reading comprehension and writing composition. [ABSTRACT FROM AUTHOR]

This study investigated the relationship between mathematics difficulties and psychopathology in a large community sample (N = 881) of youth (8–18 years of age) in the United States. The primary aims of the study were to (a) test the associations between mathematics difficulties and specific components of internalizing, externalizing, attention, and social problems; (b) examine potential age and gender differences; and (c) investigate the longitudinal relationship between mathematics and psychopathology using 5-year follow-up data. Results indicated that individuals with mathematics difficulties exhibited elevations in most dimensions of psychopathology, including anxiety, depression, externalizing behaviors, attention problems, and social problems. Furthermore, mathematics impairment was associated with internalizing problems, rule-breaking behaviors, inattention, and social problems even after controlling for comorbid reading difficulties. Results suggested that the associations between mathematics and psychopathology are generally similar in males and females. Finally, preliminary longitudinal evidence suggested that initial mathematics difficulties predicted elevations of conduct disorder, rule-breaking behavior, inattention, hyperactivity, and social problems at follow-up, with several of these associations remaining significant even after controlling for initial reading. In contrast, there was no significant association between initial mathematics ability and internalizing symptoms at follow-up, demonstrating some amelioration of internalizing symptoms over time. [ABSTRACT FROM AUTHOR]

Previous work suggests that symptoms of attention-deficit/hyperactivity disorder (ADHD) are associated with procrastination in college students, but relatively little is known about markers that account for this relation. In the present study, we examined the relation between ADHD symptoms and procrastination and whether indirect effects through emotion regulation and self-esteem independently and/or serially account for this relation. Five hundred ninety-five college students (79.5% female; 84.7% white; 94.3% between 18 and 22 years of age) completed a variety of online self-report measures assessing ADHD symptoms, emotion dysregulation, self-esteem, and procrastination. Difficulties in emotion regulation and self-esteem partially accounted for the relation between ADHD symptoms and procrastination individually in simple mediation models as well as together in a serial mediation model. These results are consistent with previous literature linking ADHD symptoms to greater difficulties in emotion regulation, lower self-esteem, and more frequent procrastination. This work suggests that improving emotion regulation skills and self-esteem in college students with symptoms of ADHD should be an important goal of treatment, but future work using longitudinal data is needed to gain a better understanding of the temporal relations among these variables. [ABSTRACT FROM AUTHOR]

It has become clear in recent years that reading, while relying on domain-specific language processing regions, also involves regions that implement executive processes more broadly. Such executive control is generally considered to be implemented by prefrontal regions, which exert control via connectivity that allows them to modulate processing in target brain regions. The present study examined whether three previously identified and distinct executive control regions in the pFC [Wang, K., Banich, M. T., Reineberg, A. E., Leopold, D. R., Willcutt, E. G., Cutting, L. E., et al. Left posterior prefrontal regions support domain-general executive processes needed for both reading and math. Journal of Neuropsychology, 14, 467–495, 2020] show similar patterns of functional connectivity (FC) during a reading comprehension task as compared with a symbol identification condition. Our FC results in a sample of adolescents (n = 120) suggest all three regions commonly show associations with activity in "classic" left hemisphere reading areas, including the angular and supramarginal gyri, yet each exhibits differential connectivity as well. In particular, precentral regions show differential FC to parietal portions of the dorsal language stream, the inferior frontal junction shows differential FC to middle temporal regions of the right hemisphere and other regions involved in semantic processing, and portions of the inferior frontal gyrus show differential FC to an extensive set of right hemisphere prefrontal regions. These results suggest that prefrontal control over language-related regions occurs in a coordinated yet discrete manner. [ABSTRACT FROM AUTHOR]

Objective: In the last decade, there has been an increase in research that aims to parse heterogeneity in attention deficit hyperactivity disorder (ADHD). The current study tests heritability of latent class neuropsychological subtypes. Method: Latent class analysis was used to derive subtypes in a sample of school-age twins (N = 2,564) enriched for elevated ADHD symptoms. Results: Five neuropsychological profiles replicated across twin 1 and twin 2 datasets. Latent class membership was heritable overall, but heritability varied by profile and was lower than heritability of ADHD status. Variability in neuropsychological performance across domains was the strongest predictor of elevated ADHD symptoms. Neuropsychological profiles showed distinct associations with age, psychiatric symptoms and reading ability. Conclusion: Neuropsychological profiles are associated with unique neurocognitive presentations, but are not strong candidate endophenotypes for ADHD diagnosis. [ABSTRACT FROM AUTHOR]

The current study utilized a large, unselected sample of adolescent twins to examine whether processing speed (PS) is an important shared predictor that accounts for covariance among reading, math, ADHD, and rapid naming (RN). The best fitting model included correlated but distinguishable latent measures of PS, RN, reading, math, inattention, hyperactivity/impulsivity, and academic fluency. PS was a shared predictor across all outcomes, while RN was uniquely associated with reading, fluency, and (albeit weakly) math. The results add to a growing literature suggesting that PS and RN may be important components of comprehensive neuropsychological models of academics, ADHD, and their covariation. [ABSTRACT FROM AUTHOR]

Despite historical emphasis on "specific" learning disabilities (SLDs), academic skills are strongly correlated across the curriculum. Thus, one can ask how specific SLDs truly are. To answer this question, we used bifactor models to identify variance shared across academic domains (academic g), as well as variance unique to reading, mathematics, and writing. Participants were 686 children ages 8 to 16. Although the sample was overselected for learning disabilities, we intentionally included children across the full range of individual differences in this study in response to growing recognition that a dimensional, quantitative view of SLD is more accurate than a categorical view. Confirmatory factor analysis identified five academic domains (basic reading, reading comprehension, basic math, math problem-solving, and written expression); spelling clustered with basic reading and not writing. In the bifactor model, all measures loaded significantly on academic g. Basic reading and mathematics maintained variance distinct from academic g, consistent with the notion of SLDs in these domains. Writing did not maintain specific variance apart from academic g, and evidence for reading comprehension-specific variance was mixed. Academic g was strongly correlated with cognitive g (r =.72) but not identical to it. Implications for SLD diagnosis are discussed. [ABSTRACT FROM AUTHOR]

Attention-deficit/hyperactivity disorder (ADHD) is characterized by inattentive, hyperactive, and impulsive behaviors. Impairment in individuals diagnosed with ADHD is significant; one such domain of impairment is achieving a college education. College students with ADHD tend to have lower grade point averages, take longer to graduate, and have higher dropout rates than individuals without ADHD. Those with ADHD may be inadequately prepared for college. College readiness can be broken into self-determination, academic skills, and daily living skills, all of which are possible areas of deficit for individuals with ADHD, given their common characteristics. In the current study, we examined differences in college readiness in undergraduates with and without ADHD. In general, students with ADHD were found to be less prepared for college than those without ADHD, and specific areas of unpreparedness were identified. The findings support the need for intervention for students with ADHD before or early in their college careers. Further research on specific skill deficits and ameliorative steps is needed. [ABSTRACT FROM AUTHOR]

This paper extends the understanding of the relation between ADHD and reading comprehension, through examining how this relation differs depending on the quantile an individual falls in for each. Samples from three twin projects around the United States were used (Florida Twin Project, Colorado component of International Longitudinal Twin Study of Early Reading Development, & Western Reserve Reading and Math Projects). Phenotypic analysis using quantile regression showed relations between ADHD related behaviors and reading comprehension to be stronger in the lower quantiles of reading comprehension in two of three samples. A new method was developed extending this analysis into the bivariate genetic space. Results of this quantile genetic analysis revealed that overlapping common environmental influences accounted for a larger proportion of variance in the lower quantiles of these variables in two of three samples. Finally, in all three samples the phenotypic relation was strongest when shared environmental influences accounted for a larger proportion of the overall variance. [ABSTRACT FROM AUTHOR]

This study examined whether strong cognitive skills (i.e. vocabulary, rapid naming, verbal working memory [VWM], and processing speed [PS]) contributed to resilience in single-word reading skills in children at risk for reading difficulties because of low phonological awareness scores (PA). Promotive factors were identified by main effects and protective factors through PA x cognition interactions. This study included 1,807 children ages 8–16. As predicted, all cognitive skills were significantly related to reading, consistent with promotive effects. A significant, but small effect PA x vocabulary interaction (R2 change =.002, p =.00038) was detected but its form was not consistent with a classic protective effect. Rather, the PA x vocabulary interaction was consistent with a "skill-enhancement" pattern, such that children with strong PA and vocabulary skills had better than expected reading. This study provides a framework for reading resilience research and directs attention to promotive mechanisms underlying reading success. [ABSTRACT FROM AUTHOR]

Sluggish cognitive tempo (SCT) is marked by impairments across social, emotional, and academic functioning, but few studies have examined the association between SCT and neuropsychological functioning. The present study examined the associations between SCT and measures of processing speed, executive function, attention, and reaction time. From a larger sample of 8,238 children and adolescents, a subsample of 928 children were overselected for symptoms of SCT or attention-deficit/hyperactivity disorder (ADHD) and compared to a matched control sample of 652 individuals without elevations of ADHD or SCT (age range = 5.9–15.4 years). Multiple regression analyses revealed that symptoms of SCT were independently associated with deficits in nearly all domains assessed by a battery of neuropsychological assessments, including slower processing speed, poorer working memory, decreased inhibition, poorer vigilance, and increased reaction time. Further, weaknesses in all five of these domains remained significant even after symptoms of ADHD-inattention, anxiety, and depression were controlled. These findings add to literature that supports the validity of SCT as a symptom profile separate from ADHD-inattention symptoms. [ABSTRACT FROM AUTHOR]

Evidence-based practice in psychology (EBPP) has long focused on treatment, but evidence-based psychological assessment (EBPA) is also crucial given the important role of accurate and reliable diagnostic practices in treatment planning. In terms of the diagnosis of attention-deficit/hyperactivity disorder (ADHD), EBPA practices are well-established for children, and more recently for adults, but for college students in particular there are special considerations that warrant attention. College students with symptoms of ADHD have some challenges that are unique, and thus the assessment and diagnosis of ADHD in these students is unique. The aim of this review is not to cover all EBPA strategies for diagnosing ADHD in emerging adult college students; rather, we will focus on the unique considerations at play in college ADHD assessment. These include (a) conceptual matters such as the appropriateness of the DSM-5 criteria for college students, the limitations of our understanding of ADHD this population because of a lack of diversity in research studies, and the issue of late-identified ADHD; and (b) practical matters, such as specific documentation needs, how to gather and interpret self- and other-report of symptoms, how to assess impairment, and alternate explanations for ADHD-like symptoms in college students. [ABSTRACT FROM AUTHOR]

Objective: ADHD and anxiety symptoms are highly comorbid in childhood. While worse functional outcomes are typically expected for children with comorbid ADHD and anxiety symptoms, an emerging body of literature has suggested that anxiety symptoms may actually contribute to compensatory effects for executive functioning (EF) skills in children with ADHD symptoms. However, the results of studies investigating this claim have been quite mixed, possibly due to the use of smaller sample sizes and cross-sectional datasets. The current study extends the previous literature by examining the possible compensatory effects of anxiety symptoms in the context of ADHD symptoms on EF abilities (e.g., working memory [WM] and inhibition) both cross-sectionally and longitudinally in a large, well-validated sample. Participants and Methods: 547 children and adolescents (8-16 years) were included from a population-based sample of twins (CLDRC sample) with enrichment for reading and attention challenges. Participants were retested at a second time point approximately 5 years later. ADHD symptoms (inattention and hyperactivity-impulsivity) were measured by a DSM-based ADHD rating scale, anxiety symptoms were measured by the RCMAS, inhibition was measured by stop-signal reaction time (SSRT), and working memory was measured by Digit Span Backwards (WISC/WAIS-R/III). Covariates included age and sex assigned at birth. Multiple regression models examined cross-sectional and longitudinal associations between ADHD (inattention and H-I) symptoms, anxiety symptoms, and the interaction between ADHD and anxiety symptoms on WM and inhibition abilities. Results: As expected, higher anxiety, inattention, and H-I symptoms were generally associated with lower inhibition and WM abilities both cross-sectionally and longitudinally. While no significant interactions between ADHD and anxiety symptoms were identified cross-sectionally at Time 1, significant interactions between Time 1 ADHD and anxiety symptoms predicted Time 2 inhibition scores. An inattention x anxiety interaction (p=.002) and a H-I x anxiety (p=.016) interaction significantly predicted Time 2 inhibition. Simple slopes analysis confirmed a compensatory interaction pattern, where ADHD symptoms showed a stronger association with inhibition weaknesses in children without anxiety symptoms compared to those with anxiety symptoms. This suggests that anxiety symptoms may be serving as a compensatory factor for children with ADHD symptoms as compared to their peers without ADHD symptoms. Conclusions: These findings help clarify a previously mixed literature. Our findings suggest that the compensatory effect of anxiety symptoms on inhibition abilities in children with ADHD symptoms may be a developmental mechanism that takes time to emerge. The fact that the compensatory effect may take time to emerge may explain conflicting results within prior cross-sectional samples. These findings also have implications for research investigating the link between ADHD symptoms and EF abilities, as anxiety symptoms may be an important moderator to consider when attempting to explain why the correlation between ADHD symptoms and EF abilities is often weaker than expected. Finally, clinical implications for this work help to provide empirical evidence to support anecdotal experiences reported by individuals with ADHD and the clinicians who assess them, who often report that anxiety symptoms help them to improve EF performance. [ABSTRACT FROM AUTHOR]

Substantial evidence has suggested that reading and math are supported by executive processes (EP). However, to date little is known about which portion of the neural system underpinning domain‐general executive skills works to support reading and math. In this study, we aimed to answer this question using fMRI via two complementary approaches. First, imaging data were acquired whilst a sample of 231 adolescents performed each of three separate tasks designed to assess reading comprehension, numerical magnitude estimation, and EP in working memory (WM), respectively. With careful task designs and conjunction analyses, we were able to isolate cross‐domain brain activity specifically related to EP, as opposed to lower‐level domain‐general processes (e.g., visual processing). Second, the meta‐analytic tool Neurosynth was used to independently identify brain regions involved reading, math, and EP. Using a combination of forward and reverse statistical inference and conjunction analyses, we again isolated brain regions specifically supporting domain‐general EP. Results from both approaches yielded overlapping activation for reading, math, and EP in the left ventrolateral prefrontal cortex, left inferior frontal junction, and left precentral gyrus. This pattern suggests that posterior regions of the prefrontal cortex, rather than more central regions such as mid‐DLPFC, play a leading role in supporting domain‐general EP utilized by both reading and math. [ABSTRACT FROM AUTHOR]

The objective was to determine the proportion of trait (consistency across occasions) and occasion-specific variance in sluggish cognitive tempo (SCT), attention deficit/hyperactivity disorder (ADHD)–inattention (IN), ADHD–hyperactivity/impulsivity (HI), and oppositional defiant disorder (ODD) symptom ratings. A single trait factor-multiple state factors model was applied to parent ratings of SCT, ADHD-IN, ADHD-HI, and ODD symptoms for 978 children (50% female) across prekindergarten (M = 4.90 years), kindergarten (M = 6.27 years), 1st-grade (M = 7.42 years), 2nd-grade (M = 8.45 years), and 4th-grade (M = 10.45 years) assessments. For the prekindergarten assessment, SCT, ADHD-IN, ADHD-HI, and ODD contained more occasion-specific than trait variance (54%, 64%, 56%, and 55% occasion-specific variance, respectively). In contrast, SCT, ADHD-IN, ADHD-HI, and ODD contained more trait than occasion-specific variance for the kindergarten through 4th-grade assessments (62%–72%, 65%–68%, 71%–75%, and 60%–69% trait variance, respectively). SCT, ADHD-IN, ADHD-HI, and ODD are slightly to moderately more state-like than trait-like during the prekindergarten developmental period but are more stable traits than fluctuating states from kindergarten to 4th grade. Findings indicate that, particularly after children start formal schooling, these psychopathology dimensions are primarily stable traits; implications for assessment are discussed. [ABSTRACT FROM AUTHOR]

Emerging research has identified sluggish cognitive tempo (SCT) as a construct separate from ADHD predominately inattentive presentation. The present study explores the longitudinal stability of SCT over a period of 7 years, specifically the independent effects of SCT on behavioural and academic outcomes concurrently over a 3-year period. A sample of 639 twins, aged 6–12 years, participating in the Western Reserve Reading and Math Project (WRRMP) were assessed at seven annual home visits. The WRRMP sample is an unselected sample of twins representative of the general population of typically developing school-age children. The current investigation will focus on parent and teacher reports which assess attention deficit hyperactive/impulsive disorder (ADHD) and standardized achievement measures which assess academic outcomes. Over periods longer than 1 or 2 years, SCT does not display good longitudinal stability (r <.60). SCT also does not have consistent significant independent effects on academic outcomes once the effects of ADHD were controlled for. Over a 7-year period, SCT does not demonstrate consistent longitudinal stability. SCT significantly predicts social problems, internalizing behaviours, and anxious/depressive behaviours after the effects of ADHD are controlled for. SCT has no significant independent effects on cognitive or educational outcomes after the effects of inattentive ADHD are controlled for. [ABSTRACT FROM AUTHOR]

Objective: Approximately 5% of adults have ADHD. Despite recommendations regarding the diagnosis of emerging adults, there is not a strong consensus regarding the ideal method for diagnosing ADHD in both emerging and mature adults. We were interested in determining whether a threshold of four, five, or six ADHD symptoms would be associated with significantly different levels of functional impairment and be more or less indicative of a potential ADHD diagnosis.Method: We examined the relation between functional impairment and these ADHD symptom thresholds in 2,577 college students.Results: Our findings suggest that none of these symptom thresholds are differentially better at predicting functional impairment.Conclusion: The Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) threshold of five symptoms for ages 17 years and older is not necessarily predictive of ADHD-related impairment in college students and may not be preferable to other thresholds. Options for resolving this diagnostic dilemma are discussed. [ABSTRACT FROM AUTHOR]

We examined the predictive value of early spelling for later reading performance by analyzing data from 970 U.S. children whose spelling was assessed in the summer following the completion of kindergarten (M age = 6 years; 3 months). The word reading performance of most of the children was then tested after the completion of Grade 1 (age 7;5), Grade 2 (8;5), Grade 4 (10;5), and Grade 9 (15;5). A computer-scored measure of postkindergarten spelling was a significant predictor of later reading performance even after taking into account postkindergarten phonological awareness, reading, and letter-sound knowledge and prekindergarten vocabulary. The results suggest that, by the end of kindergarten, spelling is more than just a proxy for phonological awareness and letter-sound knowledge. Given the information that spelling provides, it should be considered for inclusion when screening children for future literacy problems. [ABSTRACT FROM AUTHOR]

Background Rapid automatised naming (RAN) and rapid alternating stimulus (RAS) are reliable predictors of reading disability. The underlying biology of reading disability is poorly understood. However, the high correlation among RAN, RAS and reading could be attributable to shared genetic factors that contribute to common biological mechanisms. Objective To identify shared genetic factors that contribute to RAN and RAS performance using a multivariate approach. Methods We conducted a multivariate genome-wide association analysis of RAN Objects, RAN Letters and RAS Letters/Numbers in a sample of 1331 Hispanic American and African-American youth. Follow-up neuroimaging genetic analysis of cortical regions associated with reading ability in an independent sample and epigenetic examination of extant data predicting tissue-specific functionality in the brain were also conducted. Results Genome-wide significant effects were observed at rs1555839 (p=4.03x10-8) and replicated in an independent sample of 318 children of European ancestry. Epigenetic analysis and chromatin state models of the implicated 70 kb region of 10q23.31 support active transcription of the gene RNLS in the brain, which encodes a catecholamine metabolising protein. Chromatin contact maps of adult hippocampal tissue indicate a potential enhancer-promoter interaction regulating RNLS expression. Neuroimaging genetic analysis in an independent, multiethnic sample (n=690) showed that rs1555839 is associated with structural variation in the right inferior parietal lobule. Conclusion This study provides support for a novel trait locus at chromosome 10q23.31 and proposes a potential gene-brain-behaviour relationship for targeted future functional analysis to understand underlying biological mechanisms for reading disability. [ABSTRACT FROM AUTHOR]

Previous studies within the United States suggest there are cultural and contextual influences on how attention-deficit/hyperactivity disorder (ADHD) symptoms are perceived. If such influences operate within a single country, they are likely to also occur between countries. In the current study, we tested whether country differences in mean ADHD scores also reflect cultural and contextual differences, as opposed to actual etiological differences. The sample for the present study included 974 participants from four countries tested at two time points, the end of preschool and the end of second grade. Consistent with previous research, we found lower mean ADHD scores in Norway and Sweden in comparison with Australia and the United States, and we tested four explanations for these country differences: (a) genuine etiological differences, (b) slower introduction to formal academic skills in Norway and Sweden than in the United States and Australia that indicated a context difference, (c) underreporting tendency in Norway and Sweden, or (d) overreporting tendency in the United States and Australia. Either under- or overreporting would be examples of cultural differences in the perception of ADHD symptoms. Of these explanations, results of ADHD measurement equivalence tests across countries rejected the first three explanations and supported the fourth explanation: an overreporting tendency in the United States and Australia. These findings indicate that parental reporting of ADHD symptoms is more accurate in Norway and Sweden than in Australia and the United States, and, thus, have important clinical and educational implications for how parental reporting informs an ADHD diagnosis in these countries. [ABSTRACT FROM AUTHOR]

The causes that individuals attribute to reading outcomes shape future behaviors, including engagement or persistence with learning tasks. Although previous reading motivation research has examined differences between typical and struggling readers, there may be unique dynamics related to varying levels of reading and attention skills. Using latent profile analysis, we found 4 groups informed by internal attributions to ability and effort. Reading skills, inattention, and hyperactivity/impulsivity were investigated as functional correlates of attribution profiles. Participants were 1,312 youth (8–15 years of age) of predominantly African American and Hispanic racial/ethnic heritage. More adaptive attribution profiles had greater reading performance and lower inattention. The reverse was found for the least adaptive profile with associations to greater reading and attention difficulties. Distinct attribution profiles also existed across similar-achieving groups. Understanding reading-related attributions may inform instructional efforts in reading. Promoting adaptive attributions may foster engagement with texts despite learning difficulties and, in turn, support reading achievement. [ABSTRACT FROM AUTHOR]

Current definitions of specific learning disability (SLD) identify a heterogeneous population that includes individuals with weaknesses in reading, math, or writing, and these academic difficulties often co‐occur in many of the same individuals. The Colorado Learning Disabilities Research Center (CLDRC) is an interdisciplinary, multisite research program that uses converging levels of analysis to understand the genetic and environmental etiology, neuropsychology, and developmental outcomes of SLDs in reading (RD), math (MD), and writing (WD), along with the comorbidity between these SLDs and other developmental disorders. The latest results from the CLDRC twin study suggest that shared genetic influences contribute to the significant covariance between all aspects of reading (word reading, reading fluency, and reading comprehension) and math (calculations, math fluency, and word problems), and distinct genetic or environmental influences also contribute to weaknesses in each specific academic domain. RD and MD are associated with a range of negative outcomes on both concurrent measures and measures of functional outcomes completed 5 years after the twins were first assessed. Over the next several years the CLDRC will continue to expand on this work by administering a comprehensive test battery that includes measures of all dimensions of academic achievement that are described in current definitions of SLD and incorporating these measures in new neuroimaging and molecular genetic studies. [ABSTRACT FROM AUTHOR]

Sluggish cognitive tempo (SCT) is separable from attention-deficit/hyperactivity disorder (ADHD) and other psychopathologies, and growing evidence demonstrates SCT to be associated with impairment in both children and adults. However, it remains unclear how SCT should optimally be conceptualized. In this article, we argue that multiple models of psychopathology should be leveraged to make substantive advances to our understanding of SCT. Both categorical and dimensional approaches should be used, including the Diagnostic and Statistical Manual of Mental Disorders (DSM) nosology, the Research Domain Criteria (RDoC) initiative, and hierarchical models of psychopathology. Studies are needed to determine whether individuals categorized with SCT can be reliably identified and differentiated from individuals without SCT in pathophysiological, neuropsychological, behavioral, and daily life functioning. Studies are also needed to evaluate the validity and utility of SCT as a transdiagnostic and dimensional construct. In considering SCT as a dimensional and potentially transdiagnostic construct, we describe ways in which SCT might be examined within the RDoC framework, including negative valence systems, cognitive systems, and arousal/regulatory systems, as well as within hierarchical models of psychopathology. Conceptualizing SCT within both categorical and dimensional models of psychopathology will help to better understand the causes, developmental pathways, and clinical implications of SCT, both as a construct in its own right and also in relation to other psychopathologies. [ABSTRACT FROM AUTHOR]

Objective: There is increasing interest in examining a general psychopathology factor (p factor) in children and adolescents. In previous work, the relationship between the p factor and cognition in youth has largely focused on general intelligence (IQ) and executive functions (EF). Another cognitive construct, processing speed (PS), is dissociable from these cognitive constructs, but has received less research attention despite being related to many different mental health symptoms. This study aimed to examine the association between a latent processing speed factor and the p factor in youth. Participants and Methods: The present sample included 795 youth, ages 11-16 from the Colorado Learning Disability Research Center (CLDRC) sample. Confirmatory factor analyses tested multiple p factor models, with the primary model being a novel second-order, multireporter p factor where caregivers reported on externalizing symptoms (oppositional defiant disorder and conduct disorder modules from the Diagnostic Interview for Children and Adolescents [DICA]; aggression, delinquency, and attention problems subscales from the Child Behavior Checklist; and inattentive and hyperactive/impulsive subscales from the Disruptive Behavior Rating Scale) and youth self-reported on internalizing symptoms (Child Depression Inventory, generalized anxiety module from the DICA, and withdrawn, anxious/depression, and somatic subscales from the Youth Self Report). We then tested the correlation between the p factor and a latent PS factor. The latent PS factor was composed of WISC Symbol Search, WISC Coding, Colorado Perceptual Speed Test, and Identical Pictures Test. Three secondary p factor models were examined for comparison to previous literature, including (1) a bifactor, multi-reporter model, (2) a second-order model with just caregiver-report, and (3) a bifactor model with just caregiver-report. Results: There was a significant, negative correlation between the p factor and PS (r=-0.42, p<.001), indicating that slower processing speed is associated with higher general mental health symptoms. This finding was robust across models that used different raters (youth and caregiver-report vs. caregiver-report only) and modeling approaches (second-order vs. bifactor). This association is stronger than previously reported associations with IQ or EF in the p factor literature. Further, in this sample, we found that the association between PS and the p factor was robust to covariation for general cognition, whereas the correlation between general cognition and the p factor was fully accounted for by PS. Conclusions: Our findings indicate that PS is related to general psychopathology symptoms, expanding the existing literature relating PS to specific, distinct disorders by showing that PS is related to what is shared across psychopathology. As cognition and psychopathology both undergo significant development across childhood and adolescence, elucidating neurodevelopmental mechanisms that relate to risk for a broad range of symptoms may be critical to informing early intervention and prevention approaches. This research points to processing speed as an important transdiagnostic construct that warrants further attention and exploration across development. [ABSTRACT FROM AUTHOR]

Environmental factors play a key role in the development of Attention-Deficit/Hyperactivity Disorder (ADHD), but the long-term effects of these factors are still unclear. This study analyses data from 1024 monozygotic (identical) twins in Australia, the United States, and Scandinavia who were assessed for ADHD in Preschool, Kindergarten, Grade 1, and Grade 2. Differences within each twin pair were used as a direct measure of non-shared environmental effects. The Trait-State-Occasion (TSO) model developed by Cole et al. (Psychological Methods, 10, 3-20, 2005) was used to separate the non-shared environmental effects into stable factors, and transient factors that excluded measurement error. Stable factors explained, on average, 44 % and 39 % of the environmental variance in hyperactive-impulsive and inattentive symptoms, respectively. Transient effects explained the remaining 56 % and 60 % of variance. The proportion of stable variance was higher than expected based on previous research, suggesting promise for targeted interventions if future research identifies these stable risk factors. [ABSTRACT FROM AUTHOR]

Disorders of reading, math, and attention frequently co-occur in children. However, it is not yet clear which cognitive factors contribute to comorbidities among multiple disorders and which uniquely relate to one, especially because they have rarely been studied as a triad. Thus, the present study considers how reading, math, and attention relate to phonological awareness, numerosity, working memory, and processing speed, all implicated as either unique or shared correlates of these disorders. In response to findings that the attributes of all three disorders exist on a continuum rather than representing qualitatively different groups, this study employed a dimensional approach. Furthermore, we used both timed and untimed academic variables in addition to attention and activity level variables. The results supported the role of working memory and phonological awareness in the overlap among reading, math, and attention, with a limited role of processing speed. Numerosity was related to the comorbidity between math and attention. The results from timed variables and activity level were similar to those from untimed and attention variables, although activity level was less strongly related to cognitive and academic/attention variables. These findings have implications for understanding cognitive deficits that contribute to comorbid reading disability, math disability, and/or attention-deficit/hyperactivity disorder. [ABSTRACT FROM AUTHOR]

A population-based longitudinal sample of 489 twin pairs was assessed at six time points over ten years to examine the measurement invariance and stability of attention-deficit/hyperactivity disorder (ADHD) symptoms, as well as the developmental relations between inattention (IN), hyperactivity-impulsivity (HI), and multiple aspects of functional impairment. Parent ratings of ADHD symptoms and functional impairment were obtained in preschool and after the completion of kindergarten, first, second, fourth, and ninth grades. Results of the temporal and sex invariance models indicated that parent ratings of the 18 ADHD symptoms function in the same manner for females and males from early childhood into adolescence. In addition to establishing this prerequisite condition for the interpretation of longitudinal and between-sex differences in the IN and HI symptom dimensions, cross-lagged models indicated that both IN and HI were associated with increased risk for both concurrent and future overall, social, and recreational impairment, whereas only IN was uniquely associated with later academic impairment. Taken together, the current results demonstrate that IN and HI are highly stable from preschool through ninth grade, invariant between females and males, and indicative of risk for impairment in multiple areas, thereby providing strong support for the validity of the symptom dimensions among both sexes. [ABSTRACT FROM AUTHOR]

Background: Sluggish cognitive tempo (SCT) is distinct from attention‐deficit/hyperactivity disorder inattention (ADHD‐IN) and concurrently associated with a range of impairment domains. However, few longitudinal studies have examined SCT as a longitudinal predictor of adjustment. Studies to date have all used a relatively short longitudinal time span (6 months to 2 years) and only rating scale measures of adjustment. Using a prospective, multi‐method design, this study examined whether SCT and ADHD‐IN were differentially associated with functioning over a 10‐year period between preschool and the end of ninth grade. Methods: Latent state‐trait modeling determined the trait variance (i.e. consistency across occasions) of SCT and ADHD‐IN across four measurement points (preschool and the end of kindergarten, first grade, and second grade) in a large population‐based longitudinal sample (N = 976). Regression analyses were used to examine trait SCT and ADHD‐IN factors in early childhood as predictors of functioning at the end of ninth grade (i.e. parent ratings of psychopathology and social/academic functioning, reading and mathematics academic achievement scores, processing speed and working memory). Results: Both SCT and ADHD‐IN contained more trait variance (Ms = 65% and 61%, respectively) than occasion‐specific variance (Ms = 35% and 39%) in early childhood, with trait variance increasing as children progressed from preschool through early elementary school. In regression analyses: (a) SCT significantly predicted greater withdrawal and anxiety/depression whereas ADHD‐IN did not uniquely predict these internalizing domains; (b) ADHD‐IN uniquely predicted more externalizing behaviors whereas SCT uniquely predicted fewer externalizing behaviors; (c) SCT uniquely predicted shyness whereas both SCT and ADHD‐IN uniquely predicted global social difficulties; and (d) ADHD‐IN uniquely predicted poorer math achievement and slower processing speed whereas SCT more consistently predicted poorer reading achievement. Conclusions: Findings of this study – from the longest prospective sample to date – provide the clearest evidence yet that SCT and ADHD‐IN often differ when it comes to the functional outcomes they predict. [ABSTRACT FROM AUTHOR]

Copyright of Reading Research Quarterly is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Eleven loci with prior evidence for association with reading and language phenotypes were sequenced in 96 unrelated subjects with significant impairment in reading performance drawn from the Colorado Learning Disability Research Center collection. Out of 148 total individual missense variants identified, the chromosome 7 genes CCDC136 and FLNC contained 19. In addition, a region corresponding to the well-known DYX2 locus for RD contained 74 missense variants. Both allele sets were filtered for a minor allele frequency ≤0.01 and high Polyphen-2 scores. To determine if observations of these alleles are occurring more frequently in our cases than expected by chance in aggregate, counts from our sample were compared to the number of observations in the European subset of the 1000 Genomes Project using Fisher's exact test. Significant P values were achieved for both CCDC136/FLNC ( P = 0.0098) and the DYX2 locus ( P = 0.012). Taken together, this evidence further supports the influence of these regions on reading performance. These results also support the influence of rare variants in reading disability. [ABSTRACT FROM AUTHOR]

Competent reading requires various skills beyond those for basic word reading (i.e., core language skills, rapid naming, phonological processing). Contributing "higher-level" or domain-general processes include information processing speed and executive functions (working memory, strategic problem solving, attentional switching). Research in this area has relied on largely Caucasian samples, with limited representation of children from racial or ethnic minority groups. This study examined contributions of executive skills to reading competence in 761 children of minority backgrounds. Hierarchical linear regressions examined unique contributions of executive functions (EF) to word reading, fluency, and comprehension. EF contributed uniquely to reading performance, over and above reading-related language skills; working memory contributed uniquely to all components of reading; while attentional switching, but not problem solving, contributed to isolated and contextual word reading and reading fluency. Problem solving uniquely predicted comprehension, suggesting that this skill may be especially important for reading comprehension in minority youth. Attentional switching may play a unique role in development of reading fluency in minority youth, perhaps as a result of the increased demand for switching between spoken versus written dialects. Findings have implications for educational and clinical practice with regard to reading instruction, remedial reading intervention, and assessment of individuals with reading difficulty. [ABSTRACT FROM AUTHOR]

The current study tested a multiple-cognitive predictor model of word reading, math ability, and attention in a community-based sample of twins ages 8 to 16 years (N = 636). The objective was to identify cognitive predictors unique to each skill domain as well as cognitive predictors shared among skills that could help explain their overlap and thus help illuminate the basis for comorbidity of related disorders (reading disability, math disability, and attention deficit hyperactivity disorder). Results indicated that processing speed contributes to the overlap between reading and attention as well as math and attention, whereas verbal comprehension contributes to the overlap between reading and math. There was no evidence that executive functioning skills help account for covariation among these skill domains. Instead, specific executive functions differentially related to certain outcomes (i.e., working memory to math and inhibition to attention). We explored whether the model varied in younger versus older children and found only minor differences. Results are interpreted within the context of the multiple deficit framework for neurodevelopmental disorders. [ABSTRACT FROM AUTHOR]

Background Males are diagnosed with dyslexia more frequently than females, even in epidemiological samples. This may be explained by greater variance in males' reading performance. Methods We expand on previous research by rigorously testing the variance difference theory, and testing for mediation of the sex difference by cognitive correlates. We developed an analytic framework that can be applied to group differences in any psychiatric disorder. Results Males' overrepresentation in the low performance tail of the reading distribution was accounted for by mean and variance differences across sex. There was no sex difference at the high performance tail. Processing speed ( PS) and inhibitory control partially mediated the sex difference. Verbal reasoning emerged as a strength in males. Conclusions Our results complement a previous finding that PS partially mediates the sex difference in symptoms of attention deficit/hyperactivity disorder ( ADHD), and helps explain the sex difference in both dyslexia and ADHD and their comorbidity. [ABSTRACT FROM AUTHOR]

Socioeconomic risks ( SES risks) are robust risk factors influencing children's academic development. However, it is unclear whether the effects of SES on academic development operate universally in all children equally or whether they vary differentially in children with particular characteristics. The current study aimed to explore children's temperament as protective or risk factors that potentially moderate the associations between SES risks and academic development. Specifically, latent growth modeling ( LGM) was used in two longitudinal datasets with a total of 2236 children to examine how family SES risks and children's temperament interactively predicted the development of reading and math from middle childhood to early adolescence. Results showed that low negative affect, high effortful control, and low surgency mitigated the negative associations between SES risks and both reading and math development in this developmental period. These findings underline the heterogeneous nature of the negative associations between SES risks and academic development and highlight the importance of the interplay between biological and social factors on individual differences in development. [ABSTRACT FROM AUTHOR]

There is significant comorbidity between attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD). The conclusions of studies that examined the causes of comorbidity between ADHD and CD conflict, with some researchers finding support for the three independent disorders model and others finding support for the correlated risk factors model. We tested these models and eleven alternative hypotheses using the same analytical approach. The participants were 110 monozygotic twin pairs and 181 dizygotic twin pairs recruited from the Colorado Learning Disabilities Research Center Twin Study. The three independent disorders model did not fit the data, whereas the correlated risk factors model fit the data well. Several other comorbidity models fit the data as well as or better than the correlated risk factors model. The results suggest that correlated risk factors are a better explanation for the comorbidity between ADHD and CD than a third, independent ADHD+CD subtype. [ABSTRACT FROM AUTHOR]

Because of recent concerns about the replication of published results in the behavioral and biomedical sciences (Ioannidis, PLoS Medicine, Vol. 2, 2005, p. e124; Open Science Collaboration, Science, Vol. 349, 2015, p. 943; Pashler & Wagenmakers, Perspectives on Psychological Science, Vol. 7, 2012, pp. 528–530), we have conducted a replication of our recently published analyses of longitudinal reading performance and attention deficit-hyperactivity disorder data from twin pairs selected for reading difficulties (Wadsworth et al., Twin Research and Human Genetics, Vol. 18, 2015, pp. 755–761). Results obtained from univariate and bivariate (DeFries & Fulker, Behavior Genetics, Vol. 15, 1985, pp. 467–473; Acta Geneticae Medicae et Gemellologiae: Twin Research, Vol. 37, 1988, pp. 205–216) analyses of data from a subset of twin pairs tested in the International Longitudinal Twin Study of Early Reading Development at post-4th grade, and its continuation into high school at post-9th grade, were compared to those from our previous report. Similar measures of reading performance, the same measures of inattention and hyperactivity/impulsivity, and similar selection criteria were used in the two studies. In general, the patterns of results obtained from these two independent studies were highly similar. Thus, these results clearly illustrate the principle that findings from studies in quantitative behavioral genetics often replicate (Plomin et al., Perspectives on Psychological Science, Vol. 11, 2016, pp. 3–23). [ABSTRACT FROM PUBLISHER]

Background Although multiple cross-sectional studies have shown symptoms of sluggish cognitive tempo ( SCT) and attention-deficit/hyperactivity disorder ( ADHD) to be statistically distinct, studies have yet to examine the temporal stability and measurement invariance of SCT in a longitudinal sample. To date, only six studies have assessed SCT longitudinally, with the longest study examining SCT over a 2-year period. The overall goals of this study were to assess the 10-year longitudinal stability and interfactor relationships of ADHD and SCT symptoms among a community sample of children. Methods Confirmatory factor analysis was used to assess the temporal invariance of ADHD and SCT symptoms in a large population-based longitudinal sample (International Longitudinal Twin Study of Early Reading Development) that included children assessed at preschool and after kindergarten, first, second, fourth, and ninth grades ( n = 489). Latent autoregressive models were then estimated to assess the stability of these constructs. Results Results demonstrated invariance of item loadings and intercepts from preschool through ninth grades, as well as invariance of interfactor correlations. Results further indicated that both ADHD and SCT are highly stable across these years of development, that these symptom dimensions are related but also separable, and that hyperactivity/impulsivity and SCT are both more strongly correlated with inattention than with each other and show differential developmental trajectories. Specifically, even in the presence of latent simplex analyses providing support for the developmental stability of these dimensions, linear comparisons indicated that that mean levels of hyperactivity/impulsivity decreased with time, inattentive ratings were generally stable, and SCT tended to increase slightly across development. Conclusions This study adds to the current literature by being the first to systematically assess and demonstrate the temporal invariance and stability of ADHD and SCT across a span of 10 years. [ABSTRACT FROM AUTHOR]

Background Evidence that different neuropsychiatric conditions share genetic liability has increased interest in phenotypes with 'cross-disorder' relevance, as they may contribute to revised models of psychopathology. Cognition is a promising construct for study; yet, evidence that the same cognitive functions are impaired across different forms of psychopathology comes primarily from separate studies of individual categorical diagnoses versus controls. Given growing support for dimensional models that cut across traditional diagnostic boundaries, we aimed to determine, within a single cohort, whether performance on measures of executive functions (EFs) predicted dimensions of different psychopathological conditions known to share genetic liability. Methods Data are from 393 participants, ages 8-17, consecutively enrolled in the Longitudinal Study of Genetic Influences on Cognition (LOGIC). This project is conducting deep phenotyping and genomic analyses in youth referred for neuropsychiatric evaluation. Using structural equation modeling, we examined whether EFs predicted variation in core dimensions of the autism spectrum disorder, bipolar illness, and schizophrenia (including social responsiveness, mania/emotion regulation, and positive symptoms of psychosis, respectively). Results We modeled three cognitive factors (working memory, shifting, and executive processing speed) that loaded on a second-order EF factor. The EF factor predicted variation in our three target traits, but not in a negative control (somatization). Moreover, this EF factor was primarily associated with the overlapping (rather than unique) variance across the three outcome measures, suggesting that it related to a general increase in psychopathology symptoms across those dimensions. Conclusions Findings extend support for the relevance of cognition to neuropsychiatric conditions that share underlying genetic risk. They suggest that higher-order cognition, including EFs, relates to the dimensional spectrum of each of these disorders and not just the clinical diagnoses. Moreover, results have implications for bottom-up models linking genes, cognition, and a general psychopathology liability. [ABSTRACT FROM AUTHOR]

Background Reading disability (RD) and language impairment (LI) are heritable learning disabilities that obstruct acquisition and use of written and spoken language, respectively. We previously reported that two risk haplotypes, each in strong linkage disequilibrium (LD) with an allele of READ1, a polymorphic compound short tandem repeat within intron 2 of risk gene DCDC2, are associated with RD and LI. Additionally, we showed a non-additive genetic interaction between READ1 and KIAHap, a previously reported risk haplotype in risk gene KIAA0319, and that READ1 binds the transcriptional regulator ETV6. Objective To examine the hypothesis that READ1 is a transcriptional regulator of KIAA0319. Methods We characterised associations between READ1 alleles and RD and LI in a large European cohort, and also assessed interactions between READ1 and KIAHap and their effect on performance on measures of reading, language and IQ. We also used family-based data to characterise the genetic interaction, and chromatin conformation capture (3C) to investigate the possibility of a physical interaction between READ1 and KIAHap. Results and conclusions READ1 and KIAHap show interdependence--READ1 risk alleles synergise with KIAHap, whereas READ1 protective alleles act epistatically to negate the effects of KIAHap. The family data suggest that these variants interact in trans genetically, while the 3C results show that a region of DCDC2 containing READ1 interacts physically with the region upstream of KIAA0319. These data support a model in which READ1 regulates KIAA0319 expression through KIAHap and in which the additive effects of READ1 and KIAHap alleles are responsible for the trans genetic interaction. [ABSTRACT FROM AUTHOR]

Approximately 60% of children with reading difficulties (RD) meet criteria for at least one co-occurring disorder. The most common of these, attention deficit-hyperactivity disorder (ADHD), occurs in 20–40% of individuals with RD. Recent studies have suggested that genetic influences are responsible. To assess the genetic etiologies of RD and the comorbidity of RD and two ADHD symptom dimensions –– inattention (IN) and hyperactivity/impulsivity (H/I) –– we are conducting the first longitudinal twin study of RD and ADHD. Data from twin pairs in which at least one member of the pair met criteria for proband status for RD at initial assessment, and were reassessed 5 years later, were subjected to DeFries-Fulker (DF) analysis. Analyses of reading composite data indicated that over 60% of the proband deficit at initial assessment was due to genetic influences, and that reading deficits at follow-up were due substantially to the same genetic influences. When a bivariate DF model was fitted to reading performance and IN data, genetic influences accounted for 60% of contemporaneous comorbidity and over 60% of the longitudinal relationship. In contrast, analysis of the comorbidity between reading performance and H/I indicated that common genetic influences accounted for only about 20% of the contemporaneous and about 10% of the longitudinal relationships. Results indicate that (1) genetic influences on RD are substantial and highly stable; (2) the comorbidity between RD and IN is due largely to genetic influences, both contemporaneously and longitudinally; and (3) genetic influences contribute significantly less to the comorbidity between RD and H/I. [ABSTRACT FROM PUBLISHER]