Objective: The Strengths and Weaknesses of ADHD Symptoms and Normal Behavior (SWAN) Rating Scale differs from previous parent reports of ADHD in that it was designed to also measure variability at ...the positive end of the symptom spectrum. Method: The psychometric properties of the SWAN were tested and compared with an established measure of ADHD, the Disruptive Behavior Rating Scale (DBRS). Results: The SWAN demonstrates comparable validity, reliability, and heritability to the DBRS. Furthermore, plots of the SWAN and DBRS reveal heteroscedasticity, which supports the SWAN as a preferred measure of positive attention and impulse regulation behaviors. Conclusion: The ability of the SWAN to measure additional variance at the adaptive end of the ADHD symptom dimensions makes it a promising tool for behavioral genetic studies of ADHD.
Reading comprehension is a foundational academic skill and significant attention has focused on reading development. This report is the first to examine the stability and change in genetic and ...environmental influences on reading comprehension across Grades 1 to 6. This developmental range is particularly important because it encompasses the timespan in which most children move from learning how to read to using reading for learning. Longitudinal simplex models were fitted separately for two independent twin samples (N = 706; N = 976). Results suggested that the shared environment contributed to variance in early but not later reading. Instead, stability in reading development was largely mediated by continuous genetic influences. Thus, although reading is clearly a learned skill and the environment remains important for reading development, individual differences in reading comprehension appear to be also influenced by a core of genetic stability that persists through the developmental course of reading.
Background
Attention‐deficit/hyperactivity disorder (ADHD) symptoms and mathematics ability are associated, but little is known about the genetic and environmental influences underlying this ...association.
Methods
Data came from more than 6,000 twelve‐year‐old twin pairs from the UK population‐representative Twins Early Development Study. Parents rated each twin's behaviour using a DSM‐IV‐based 18‐item questionnaire of inattentive and hyperactive–impulsive ADHD symptoms. Mathematics tests based on the UK National Curriculum were completed by each twin. The twins also completed standardised tests of reading and general cognitive ability. Multivariate twin model fitting was applied.
Results
Inattentive and hyperactive–impulsive ADHD symptoms were highly heritable (67% and 73% respectively). Mathematics ability was moderately heritable (46%). Mathematics ability and inattentiveness showed a significantly greater phenotypic correlation (rp = −.26) and genetic correlation (rA = −.41) than mathematics ability and hyperactivity–impulsivity (rp = −.18; rA = −.22). The genetic correlation between inattentiveness and mathematics ability was largely independent from hyperactivity‐impulsivity, and was only partially accounted for by genetic influences related to reading and general cognitive ability.
Conclusions
Results revealed the novel finding that mathematics ability shows significantly stronger phenotypic and genetic associations with inattentiveness than with hyperactivity–impulsivity. Genetic associations between inattentiveness and mathematics ability could only partially be accounted for by hyperactivity–impulsivity, reading and general cognitive ability. Results suggest that mathematics ability is associated with ADHD symptoms largely because it shares genetic risk factors with inattentiveness, and provide further evidence for considering inattentiveness and hyperactivity–impulsivity separately. DNA markers for ADHD symptoms (especially inattentiveness) may also be candidate risk factors for mathematics ability and vice versa.
How Specific Are Learning Disabilities? Peterson, Robin L.; McGrath, Lauren M.; Willcutt, Erik G. ...
Journal of learning disabilities,
11/2021, Letnik:
54, Številka:
6
Journal Article
Recenzirano
Odprti dostop
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.
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.
This article has 2 primary goals. First, a brief tutorial on behavioral and molecular genetic methods is provided for readers without extensive training in these areas. To illustrate the application ...of these approaches to developmental disorders, etiologically informative studies of reading disability (RD), math disability (MD), and attention-deficit hyperactivity disorder (ADHD) are then reviewed. Implications of the results for these specific disorders and for developmental disabilities as a whole are discussed, and novel directions for future research are highlighted.
Previous family and twin studies of RD, MD, and ADHD are reviewed systematically, and the extensive molecular genetic literatures on each disorder are summarized. To illustrate 4 novel extensions of these etiologically informative approaches, new data are presented from the Colorado Learning Disabilities Research Center, an ongoing twin study of the etiology of RD, ADHD, MD, and related disorders.
RD, MD, and ADHD are familial and heritable, and co-occur more frequently than expected by chance. Molecular genetic studies suggest that all 3 disorders have complex etiologies, with multiple genetic and environmental risk factors each contributing to overall risk for each disorder. Neuropsychological analyses indicate that the 3 disorders are each associated with multiple neuropsychological weaknesses, and initial evidence suggests that comorbidity between the 3 disorders is due to common genetic risk factors that lead to slow processing speed.
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.
This study
evaluated the internal structure and convergent and discriminant evidence for
the Colorado Learning Difficulties Questionnaire (CLDQ), a 20-item parent-report
rating scale that was ...developed to provide a brief screening measure for
learning difficulties. CLDQ ratings were obtained from parents of children in 2
large community samples and 2 samples from clinics that specialize in the
assessment of learning disabilities and related disorders (total
N = 8,004). Exploratory and confirmatory factor analyses
revealed 5 correlated but separable dimensions that were labeled
reading, math, social
cognition, social anxiety, and spatial
difficulties. Results revealed strong convergent and discriminant
evidence for the CLDQ Reading scale, suggesting that this scale may provide a
useful method to screen for reading difficulties in both research studies and
clinical settings. Results are also promising for the other 4 CLDQ scales, but
additional research is needed to refine each of these measures.
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.
Although higher SES risks are generally associated with poorer academic outcomes, this relation is not universal. The current study shows that high effortful control, low surgency, and low negative affect gradually help compensate for the academic disadvantages associated with SES constraints.
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.
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