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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]

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]

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: 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]

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]

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]

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]

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]

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]

Background Males show higher rates of attention deficit hyperactivity disorder ( ADHD) than do females. Potential explanations include genuine etiological differences or artifact. Methods 2,332 twin and sibling youth participated in behavioral and cognitive testing. Partially competing models of symptom severity distribution differences, the mean difference, and variance difference models, were tested within a randomly selected subsample. The Delta method was used to test for mediation of sex differences in ADHD symptom severity by processing speed, inhibition and working memory. Results The combined mean difference and variance difference models fully explained the sex difference in ADHD symptom severity. Cognitive endophenotypes mediated 14% of the sex difference effect. Conclusions The sex difference in ADHD symptom severity is valid and may be due to differing genetic and cognitive liabilities between the sexes. [ABSTRACT FROM AUTHOR]

Background: Attention-deficit/hyperactivity disorder (ADHD) and childhood-onset psychosis (COP) are chronic, heterogeneous disorders with symptoms that frequently co-occur, but the etiology of their comorbidity is unknown. Studies of each disorder indicate that both ADHD and COP are associated with a range of neuropsychological weaknesses, but few neuropsychological studies have directly compared groups with ADHD and COP. Methods: Groups with ADHD only (32 F, 48 M), COP only (5 F, 5 M), ADHD + COP (9 F, 21 M), and a control group with neither disorder (25 F, 44 M) completed a neuropsychological battery that included measures of verbal working memory, response inhibition, response speed and variability, and selective attention. Results: All three clinical groups exhibited significantly lower performance versus the control group on all neuropsychological measures, whereas the only significant difference between the clinical groups was a significantly larger weakness in verbal working memory in the groups with COP. Conclusions: The frequent co-occurrence between COP and ADHD may reflect shared neuropsychological weaknesses that are most pronounced on measures of working memory and response variability. [ABSTRACT FROM AUTHOR]

Background: Previous studies have identified significant variability in attention-deficit / hyperactivity disorder (ADHD) prevalence estimates worldwide, largely explained by methodological procedures. However, increasing rates of ADHD diagnosis and treatment throughout the past few decades have fuelled concerns about whether the true prevalence of the disorder has increased over time.Methods: We updated the two most comprehensive systematic reviews on ADHD prevalence available in the literature. Meta-regression analyses were conducted to test the effect of year of study in the context of both methodological variables that determined variability in ADHD prevalence (diagnostic criteria, impairment criterion and source of information), and the geographical location of studies.Results: We identified 154 original studies and included 135 in the multivariate analysis. Methodological procedures investigated were significantly associated with heterogeneity of studies. Geographical location and year of study were not associated with variability in ADHD prevalence estimates.Conclusions: Confirming previous findings, variability in ADHD prevalence estimates is mostly explained by methodological characteristics of the studies. In the past three decades, there has been no evidence to suggest an increase in the number of children in the community who meet criteria for ADHD when standardized diagnostic procedures are followed. [ABSTRACT FROM PUBLISHER]

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. [ABSTRACT FROM AUTHOR]

Background: Neurocognitive deficits associated with attention-deficit/hyperactivity disorder (ADHD) might be useful intermediate endophenotypes for determining specific genetic pathways that contribute to ADHD. Methods: This study administered 17 measures from prominent neuropsychological theories of ADHD (executive function, processing speed, arousal regulation and, motivation/delay aversion) in dizygotic (DZ) twin pairs discordant for ADHD and control twin pairs (ages 8–18 years) to compare performance between twins affected with ADHD (n = 266), their unaffected co-twins (n = 228), and control children from twin pairs without ADHD or learning difficulties (n = 332). Results: The ADHD subjects show significant impairment on executive function, processing speed, and response variability measures compared with control subjects. Unaffected co-twins of ADHD subjects are significantly impaired on nearly all the same measures as their ADHD siblings, even when subclinical symptoms of ADHD are controlled. Conclusions: Executive function, processing speed, and response variability deficits might be useful endophenotypes for genetic studies of ADHD. [Copyright &y& Elsevier]

Abstract: Despite considerable research, the validity of attention-deficit/hyperactivity disorder (ADHD) remains controversial. This paper summarizes the results of a comprehensive review of the internal and external validity of ADHD as defined in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Results indicate that for most individuals DSM-IV ADHD is a valid disorder in the sense that it is associated with significant impairment in social, academic, and occupational functioning and increased risk of accidental injury across the life span. Additional research is needed, however, to clarify the diagnostic validity of the hyperactive-impulsive type and the discriminant validity of the combined and inattentive subtypes. Other areas in need of further study include potential modifications to the diagnostic conceptualization of the inattentive subtype, developmental trajectories of the subtypes, and methods to address cross-informant diagnostic inconsistencies. Such research is likely to benefit from an etiologically informed approach to examining heterogeneity both across and within subtypes. [Copyright &y& Elsevier]

Behavioral genetic studies provide strong evidence that attention-deficit/hyperactivity disorder (ADHD) has a substantial genetic component. Yet, due to the complexity of the ADHD phenotype, questions remain as to the specific genes that contribute to this condition as well as the pathways from genes to behavior. Endophenotypes, or phenotypes that are more closely linked to the neurobiological substrate of a disorder, offer the potential to address these two issues simultaneously (Freedman, Adler, & Leonard, 1999). Thus far, potential endophenotypes for ADHD have not been systematically studied. The current paper reviews evidence supporting the use of deficits on neurocognitive measures of executive functions for this purpose. Such deficits are a correlate of ADHD and show preliminary evidence of heritability and association with relevant candidate genes. Nonetheless, studies that have assessed the familial and genetic overlap of neurocognitive impairments with ADHD have yielded inconsistent results. In order for executive function deficits to be used as an endophenotype for ADHD, we recommend greater attention to the neurocognitive heterogeneity of this disorder and to the precision of measurement of the neuropsychological tests employed. We also discuss empirical strategies that may be necessary to allow such research to progress prior to full resolution of the pathophysiological basis of ADHD. [ABSTRACT FROM AUTHOR]

Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable disorder with a multifactorial pattern of inheritance. For complex conditions such as this, biologically based phenotypes that lie in the pathway from genes to behavior may provide a more powerful target for molecular genetic studies than the disorder as a whole. Although their use in ADHD is relatively new, such “endophenotypes” have aided the clarification of the etiology and pathophysiology of several other conditions in medicine and psychiatry. In this article, we review existing data on potential endophenotypes for ADHD, emphasizing neuropsychological deficits because assessment tools are cost effective and relatively easy to implement. Neuropsychological impairments, as well as measures from neuroimaging and electrophysiological paradigms, show correlations with ADHD and evidence of heritability, but the familial or genetic overlap between these constructs and ADHD remains unclear. We conclude that these endophenotypes will not be a quick fix for the field but offer potential if careful consideration is given to issues of heterogeneity, measurement and statistical power. [Copyright &y& Elsevier]

Before assigning full etiologic validity to a psycopathologic disorder, disease theory suggests that a causal dysfunction in a mechanism within the affect individuals must be identified. Existing theories on attention-deficit/hyperactivity disorder (ADHD) suggest such dysfunctions in cognitive, neuropsychological, or motivational processes in the child. To date, researchers have tested these theories by comparing groups with DSM-defined ADHD to children without ADHD. Using executive functioning as an illustration of an issue that exists across all such theories, this article describes substantial overlaps in the group performance data. Thus only a subgroup may have executive deficits. Noted are other supportive data suggesting multiple pathways to ADHD. The article explores implications and recommends that future theory and research give more consideration to the probability that only a subset of behaviorally defined children will have a deficit in a given neurocognitive mechanism believed to contribute to the disorder. Creation of a provisional set of criteria in DSM-V for defining an “executive deficit type” could stimulate research to validate the first etiologic subtype of ADHD and spur the development of more sophisticated causal models, which in the longer term may give clinicians ways to target and tailor treatments. [Copyright &y& Elsevier]

Abstract: Attention Deficit Hyperactivity Disorder (ADHD) is a widely diagnosed psychiatric disorder of childhood that may continue to manifest itself during adulthood. Across adults and children, inattention appears to be the most developmentally stable symptomatology of ADHD. To determine the neural systems that may be linked to such symptoms, the association between brain activation in a group of young adults in the face of an attentional challenge (the Stroop task) and inattentive symptoms was examined with functional magnetic resonance imaging. The results implicated a broad array of brain regions that are linked to behaviors compromised in ADHD, including executive function/cognitive control (prefrontal cortex, dorsal striatum), reward and motivational circuitry (ventral striatum), and stimulus representation and timing (posterior cortex and cerebellum). Also implicating these regions as being important for the manifestation of ADHD symptoms, the variability in the size of the BOLD signal across individuals was significantly higher for the ADHD group than for the control group, and variability across the time series in individuals with ADHD was linked to symptom severity and behavioral performance. The results suggest that a diverse set of brain structures is linked to ADHD symptoms and that the variability of activation within these regions may contribute to compromised attentional control. [Copyright &y& Elsevier]

[Correction Notice: An Erratum for this article was reported in Vol 30(3) of Psychological Assessment (see record 2017-30273-001). In the article, the Table 1 item content was incorrectly ordered. The table, as well as text referencing Table 1 in the Results and Discussion, have been corrected in all versions of this article.] As interest in sluggish cognitive tempo (SCT) increases, a primary limitation for the field is the lack of a unified set of symptoms for assessing SCT. No existing SCT measure includes all items identified in a recent meta-analysis as optimal for distinguishing between SCT and attention-deficit/hyperactivity disorder (ADHD) inattention. This study evaluates a new self-report measure for assessing SCT in adulthood, the Adult Concentration Inventory (ACI), which was developed in response to the meta-analytic findings for assessing SCT. Using a large, multiuniversity sample (N = 3,172), we evaluated the convergent and discriminant validity and reliability of the ACI. We also evaluated the ACI measure of SCT in relation to self-reported demographic characteristics, daily life executive functioning, socioemotional adjustment (i.e., anxiety/depression, loneliness, emotion dysregulation, self-esteem), and functional impairment. Exploratory confirmatory factor analyses resulted in 10 ACI items demonstrating strong convergent and discriminant validity from both anxiety/depressive and ADHD inattentive symptom dimensions. SCT was moderately to-strongly correlated with daily life EF deficits, poorer socioemotional adjustment, and greater global functional impairment. Moreover, SCT remained uniquely associated in structural regression analyses with most of these external criterion domains above and beyond ADHD. Finally, when internalizing symptoms were also covaried, SCT, but not ADHD inattention, remained significantly associated with poorer socioemotional adjustment. These findings support the use of the ACI in future studies examining SCT in adulthood and make a major contribution in moving the field toward a unified set of SCT items that can be used across studies. (PsycINFO Database Record [ABSTRACT FROM AUTHOR]

Abstract: Optimized voxel-based morphometry (VBM) was used in the present study to investigate morphometric differences between young adults with combined type Attention Deficit/Hyperactivity Disorder (ADHD) and a well-matched control group. Investigations examined differences on a between-group whole brain level, as well as how individual differences in behavioral performance predicted grey matter differences. Although a whole brain analysis revealed no significant differences between ADHD and control individuals, ADHD but not control individuals exhibited reduced grey matter volume in the right inferior frontal gyrus (rIFG), predicted by poorer behavioral performance on all three measures. A subsequent region-of-interest approach revealed lower grey matter volume in the rIFG in ADHD compared to control individuals. These results suggest that young adults with ADHD show morphometric differences in inferior prefrontal regions, as compared to controls. These morphometric differences are related to disruptions in performance on behavioral tasks that frequently have been reported to be affected in individuals with ADHD. [Copyright &y& Elsevier]

Background: Attentional control difficulties in individuals with attention-deficit/hyperactivity disorder (ADHD) might reflect poor working memory (WM) ability, especially because WM ability and attentional control rely on similar brain regions. The current study examined whether WM ability might explain group differences in brain activation between adults with ADHD and normal control subjects during attentional demand. Methods: Participants were 20 adults with ADHD combined subtype with no comorbid psychiatric or learning disorders and 23 control subjects similar in age, IQ, and gender. The WM measures were obtained from the Wechsler Adult Intelligence Scale-III and Wechsler Memory Scale-Revised. Brain activation was assessed with functional magnetic resonance imaging (fMRI) while performing a Color-Word Stroop task. Results: Group differences in WM ability explained a portion of the activation in left dorsolateral prefrontal cortex (DLPFC), which has been related to the creation and maintenance of an attentional set for task-relevant information. In addition, greater WM ability predicted increased activation of brain regions related to stimulus-driven attention and response selection processes in the ADHD group but not in the control group. Conclusions: The inability to maintain an appropriate task set in young adults with combined type ADHD, associated with decreased activity in left DLPFC, might in part be due to poor WM ability. Furthermore, in individuals with ADHD, higher WM ability might relate to increased recruitment of stimulus-driven attention and response selection processes, perhaps as a compensatory strategy. [Copyright &y& Elsevier]

Abstract: Differences in neural activation during performance on an attentionally demanding Stroop task were examined between 23 young adults with ADHD carefully selected to not be co-morbid for other psychiatric disorders and 23 matched controls. A hybrid blocked/single-trial design allowed for examination of more sustained vs. more transient aspects of attentional control. Our results indicated neural dysregulation across a wide range of brain regions including those involved in overall arousal, top-down attentional control, response selection, and inhibition. Furthermore, this dysregulation was most notable in lateral regions of DLPFC for sustained attentional control and in medial areas for transient aspects of attentional control. Because of the careful selection and matching of our two groups, these results provide strong evidence that the neural systems of attentional control are dysregulated in young adults with ADHD and are similar to dysregulations seen in children and adolescents with ADHD. [Copyright &y& Elsevier]

Detection thresholds for two visual- and two auditory-processing tasks were obtained for 73 children and young adults who varied broadly in reading ability. A reading-disabled subgroup had significantly higher thresholds than a normal-reading subgroup for the auditory tasks only. When analyzed across the whole group, the auditory tasks and one of the visual tasks, coherent motion detection, were significantly related to word reading. These effects were largely independent of ADHD ratings; however, none of these measures accounted for significant variance in word reading after controlling for full-scale IQ. In contrast, phoneme awareness, rapid naming, and nonword repetition each explained substantial, significant word reading variance after controlling for IQ, suggesting more specific roles for these oral language skills in the development of word reading. [Copyright &y& Elsevier]