Attention-deficit/hyperactivity Disorder Dimensions Research Articles

Examining ADHD and Cognitive Disengagement Syndrome Symptoms in Relation to Food Insecurity in Early Adolescents.

Approximately 13.8million U.S. households face food insecurity, which severely affects child development, with more than half of these households including children. Research links food insecurity to cognitive deficits and mental health challenges, highlighting the need for thorough understanding and intervention. Although existing studies have explored the association between food insecurity and internalizing symptomatology, less research has examined food insecurity in relation to attention-deficit/hyperactivity disorder (ADHD) symptoms. Further, no studies have explored the connection between food insecurity and cognitive disengagement syndrome (CDS) symptoms, closely related to ADHD symptoms. Despite extant research linking CDS to environmental factors, empirical attention to its potential association with food insecurity is notably lacking. Additionally, adolescents, almost twice as likely as younger children to experience household food insecurity, are likely more aware and respond differently to challenges during this developmental period. Accordingly, this study investigated the unique associations of parent-, teacher-, and youth self-reported ADHD dimensions and CDS symptoms in relation to parent-reported food insecurity in early adolescents (N = 136, ages 10-12). Controlling for age, sex, race, and medication use, no informant's ratings of ADHD symptom dimensions were uniquely related to food insecurity. In contrast, higher parent-, teacher-, and youth self-reported CDS symptoms were uniquely associated with greater food insecurity. This finding was robust to additional control of family income for teacher- and youth self-reported CDS symptoms. These findings highlight the complex link between food insecurity and mental health, suggest a connection with CDS symptoms, and stress the need to address food insecurity as a public health priority, especially in early adolescence.

Using Hot and Cool Measures to Phenotype and Predict Functional Outcomes Across Dimensions of ADHD and Typical Development in Adolescents.

Multiple pathway models propose that attention deficit hyperactivity disorder (ADHD) arises from dysfunction in separate systems comprised of a "cool" or cognitive pathway versus a "hot" or emotional/reward pathway. Interactions between these pathways and the degree of maturation may further determine functional outcomes for adolescents ranging from those diagnosed with ADHD to typical development (TD). We used a latent profile analysis on rating scales and behavioral task performance assessing emotion, irritability, impulsivity, risk-taking, future orientation, and processing speed (PS) to identify subgroups of TD adolescents and adolescents with ADHD (N = 152) based on the hot and cool pathway model. We identified four classes: 1) High-Complex Challenges; 2) Moderate-Mixed Challenges; 3) Non-Emotive Impulsivity; and 4) High Regulation and Control. A multiple pathway model of ADHD is supported with classes differing in degree of emotional lability and irritability, types of impulsivity, and ability to use future consequences to modulate impulsivity and PS. The classes differed regarding functional behavior, with the High-Complex class demonstrating the most severe functional challenges in academic-related functioning. The Moderate-Mixed class also displayed significant functional challenges but with moderate emotional lability and irritability ratings. The Non-Emotive Impulsivity class exhibited low emotionality and low irritability, yet high impulsivity with limited negative functional consequences, and was composed of a mix of ADHD and TD adolescents. Differences between classes suggest ADHD symptomatology may represent both categorical and dimensional differences. Precision health interventions may be more effective in addressing the specific challenges associated with the classes rather than a one-size-fits-all approach to treating ADHD.

Does Emotion-Related Impulsivity Relate to Specific ADHD Symptom Dimensions, and Do the Effects Generalize Across Comorbid Internalizing and Externalizing Syndromes?

Background: Recent work highlights the role of emotion dysregulation in the pathology of Attention-Deficit/Hyperactivity Disorder (ADHD). As such, emotion-related impulsivity (ERI), the trait-like tendency toward disinhibited thoughts (Pervasive Influence of Feelings, PIF) and actions (Feelings Trigger Action, FTA) during heightened emotional states, may be particularly relevant. We explored whether Inattention (IN) and Hyperactivity/Impulsivity (HI), two core symptom dimensions of ADHD, would relate to distinct facets of ERI, and whether externalizing and internalizing symptoms would moderate these relations. Method: Using structural equation modeling, we examined hypotheses among 364 adults recruited for high internalizing and externalizing symptoms. Results: We identified significant paths for FTA regressed on HI and PIF regressed on IN, supporting our hypotheses about main effects. Moderating paths were not significant. Conclusions: IN and HI correlate with distinct forms of ERI, These effects appear to generalize across co-occurring internalizing and externalizing symptoms. Theoretical and clinical implications are discussed.

The domain-variant indirect association between electrophysiological response to reward and ADHD presentations is moderated by dopaminergic polymorphisms

BackgroundUnderstanding the etiopathogenesis of attention-deficit/hyperactivity disorder (ADHD) may necessitate decomposition of the heterogeneous clinical phenotype into more homogeneous intermediate phenotypes. Reinforcement sensitivity is a promising candidate, but the exact nature of the ADHD-reward relation – including how, for whom, and to which ADHD dimensions atypicalities in reward processing are relevant – is equivocal. MethodsAims were to examine, in a carefully phenotyped sample of adolescents (N = 305; Mage = 15.30 years, SD = 1.07; 39.7% girls), whether functional dopaminergic polymorphisms implicated in both reward processing and ADHD (1) are differentially associated with event-related potentials (ERPs) of reward anticipation at distinct levels of ADHD risk (nno risk = 174, nat-risk = 131, ndiagnosed = 83); and (2) moderate the indirect effect of dispositional affectivity on the association between ERPs and ADHD domains. ResultsIn adolescents at-risk for or with ADHD, carrying a hypodopaminergic allele was associated with enhanced ERPs of attention allocation to cue and attenuated ERPs of anticipatory attention to feedback. No associations were observed in adolescents not at-risk for or without ADHD. Controlling for age and sex, both the negative indirect effect of positive affectivity (PA) on the association between ERPs and inattention and the positive indirect effect of PA on the association between ERPs and hyperactivity/impulsivity were supported only for those with high activity dopamine transporter (DAT) alleles. ConclusionsReward and affective processing are promising intermediate phenotypes relevant to disentangling ADHD developmental pathways. Consistent with developmental multifinality, through the successive effects of reward anticipation and positive affectivity, functional dopaminergic variants may confer protection against inattention or risk for hyperactivity/impulsivity.

Associations of UPPS-P negative urgency and positive urgency with ADHD dimensions: Moderation by lack of premeditation and lack of perseverance in men and women

The study examined how dimensions of Whiteside and Lynam's (2003) UPPS-P model of impulsivity (lack of premeditation, lack of perseverance, negative urgency, and positive urgency) were associated directly and interactively with the attention-deficit/hyperactivity disorder (ADHD) dimensions of inattention and hyperactivity/impulsivity in men and women separately. A total of 550 adults (men = 147, women = 403), ages ranging from 18 to 65 years, from the general community completed questionnaires covering the study variables. For women, there was support for the additive model for the prediction of inattention, and both inattention and hyperactivity/impulsivity were predicted by lack of premeditation × positive urgency. For men, inattention was predicted by lack of premeditation × negative urgency, and lack of premeditation × positive urgency. In all instances, low levels of premeditation reduced the relationships between the urgency dimensions and ADHD dimensions. The theoretical and clinical implications of the findings are discussed.

Inter-relationships between ADHD, ODD and impulsivity dimensions in emerging adults revealed by network analysis: extending the ‘trait impulsivity hypothesis’

BackgroundThe trait-impulsivity hypothesis posits impulsivity as the underlying substrate of Attention-deficit/hyperactivity disorder (ADHD) and Oppositional defiant disorder (ODD) symptom expressions. The current study applied network analysis to evaluate the inter-relationships of dimensions within ADHD (inattention and hyperactivity/impulsivity) and ODD (anger/irritable, vindictiveness, and argumentative/defiant behavior) with components of impulsivity as captured by the UPPS-P model (negative urgency, lack of premeditation, lack of perseverance, sensation seeking, and positive urgency). MethodA total of 324 emerging adults (women = 246) from the general community completed questionnaires covering these dimensions. ResultsOur findings showed that the ADHD and ODD dimensions were associated differentially with different types of impulsivity, in their unique patterns of network connectivities, a possibility that has had little attention in the trait-impulsivity hypothesis literature. ConclusionsThis study is the first to tease out the unique associations of the ADHD and ODD dimensions with different types of impulsivity, and in that way provide new contributions to our understanding of the existing trait impulsivity theory. Our findings would be especially relevant to those interested in understanding how different dimensions of trait impulsivity underly the ADHD and ODD dimensions.

Attention‐Deficit Hyperactivity Disorder Symptoms and Entrepreneurial Orientation: A Replication Note

There is a small body of literature linking attention‐deficit hyperactivity disorder (ADHD) and its symptoms to entrepreneurial manifestations. Some studies take a subclinical perspective by studying the presence of symptoms, while other studies take a clinical perspective by studying the formal diagnosis of ADHD. The entrepreneurial manifestations examined range from entrepreneurial intention to the choice to become self‐employed and from entrepreneurial orientation (EO) to entrepreneurial success. Despite its prominence in the entrepreneurship literature, to date only one study tested for a link with EO. The present study aims to replicate the relationship between ADHD symptoms and EO using a large data set of French small business owners. We do so by discriminating between the two dimensions of ADHD, namely attention‐deficit and hyperactivity, as well as the three dimensions of EO, namely innovativeness, proactiveness, and risk‐taking. We do not find a link between ADHD and EO, although we do find a positive link between ADHD and the risk‐taking subdimension of EO. Hyperactivity symptoms are positively related to EO, which is mainly driven by the subdimensions proactiveness and risk‐taking. We do not find a link between attention‐deficit symptoms and EO, though there is a negative link between attention‐deficit and proactiveness.

Emotion regulation difficulties, but not negative urgency, are associated with attention-deficit/hyperactivity disorder and eating disorder symptoms in undergraduate students

Eating disorders and attention deficit/hyperactivity disorder (ADHD) are highly comorbid. The majority of research on this comorbidity has focused on impulsivity, which is a shared vulnerability between ADHD and eating disorders characterized by binge eating. Less is known about which shared factors may contribute to the co-occurrence of other eating disorders (i.e., anorexia nervosa, restricting subtype) and ADHD. Furthermore, little research has focused on other potential overlapping vulnerabilities, though deficits in emotion regulation have been implicated as an additional shared vulnerability. The current study (N = 306 undergraduate students) uses path analysis to examine if emotion regulation difficulties and negative urgency (i.e., impulsivity during negative mood state) are unique or shared vulnerabilities for ADHD symptoms (inattention, hyperactivity-impulsivity) and eating disorder symptoms (bulimic symptoms, drive for thinness). Emotion regulation difficulties were uniquely associated with all dimensions of ADHD and eating disorder symptoms, and negative urgency was uniquely associated with global eating disorder symptoms, bulimic symptoms, and drive for thinness. These results suggest that emotion regulation difficulties are a shared vulnerability factor for the development of diverse presentations of ADHD and eating disorder symptoms, and may be an important prevention target. Additionally, our results support a unique relationship between negative urgency and drive for thinness. Future research should examine these associations prospectively and experimentally to determine directionality and inform preventative interventions for ADHD and eating disorders.

Sluggish Cognitive Tempo and ADHD Symptoms in a Nationally Representative Sample of U.S. Children: Differentiation Using Categorical and Dimensional Approaches

A nationally representative sample of U.S. children was used to determine the empirical and clinical differentiation of sluggish cognitive tempo (SCT) and attention-deficit/hyperactivity disorder (ADHD) symptoms using both categorical and dimensional approaches. Mothers of children (N = 2,056, M± SD age = 8.49 ± 2.15 years, 49.3% girls) completed measures of SCT, ADHD, oppositional defiant disorder (ODD), anxiety, depression, sleep difficulties, daily life executive functioning, conflicted shyness, friendship difficulties, and social and academic impairment. Scores greater than the top 5% on SCT and ADHD measures were used to create SCT-only (n = 53, 2.58%), ADHD-only (n = 93, 4.52%), SCT+ADHD (n = 49, 2.38%), and comparison (n = 1,861, 90.52%) groups. Fifty-two percent of the SCT group did not qualify for the ADHD group, whereas 65% of the ADHD group did not qualify for the SCT group. The SCT-only group had higher levels of anxiety, depression, conflicted shyness, and sleep difficulties than the ADHD-only group. In contrast, the ADHD-only group had greater executive functioning deficits and higher ODD than the SCT-only group. SCT-only and ADHD-only groups showed similar levels of friendship, social, and academic impairment. Similar findings emerged when using structural regression analyses to determine the unique clinical correlates of SCT and ADHD dimensions. This is only the second study to examine the distinction of clinically-elevated SCT from ADHD in a national sample of children and extends previous findings to a broader array of functional outcomes. Normative information on the SCT scale also provides a validated rating scale to advance research and clinical care.

Can the Social Behavior Questionnaire Help Meet the Need for Dimensional, Transdiagnostic Measures of Childhood and Adolescent Psychopathology?

Abstract. The shift toward transdiagnostic and dimensional approaches to psychopathology research has created a growing need for psychometric assessments that reflect this conceptualization. We aimed to test whether an omnibus measure of psychopathology, the Social Behavior Questionnaire (SBQ), has suitable properties to serve as a dimensional, transdiagnostic assessment. We used an item response theory (IRT) approach to evaluate the reliable ranges of measurement of the psychopathology dimensions measured by the SBQ. For the dimensions of attention-deficit hyperactivity disorder (ADHD), Prosociality, Internalizing, and Externalizing, the SBQ can provide a reliable measure for below average to very high levels in a normative sample.

Genetics of Adhd Dimensions

Attention-Deficit Hyperactivity Disorder (ADHD) is one of the most common and heritable childhood onset psychiatric conditions. The clinical phenotype is multidimensional with main symptoms being inattention and/or hyperactivity/impulsivity. As ADHD persists into adulthood (in up to ~80% of cases), some symptoms become more pronounced than others. Furthermore, the various aggregates of dimensions are associated with different clinical features (e.g. co-morbidities) and treatment outcomes of ADHD. So far, the biology behind such symptomatology of ADHD is far from understood. In this study, we aimed to explore the genetics of ADHD dimensions in children and their correlation with neuropsychiatric phenotypes in adulthood. The childhood sample consisted of 11,784 children from (1) Australia (N=4,000), (2) Canada (N=4,339) and (3) Norway (The Norwegian Mother Child Cohort (MoBa), N=3,445). ADHD dimensions were measured by the Strengths and Weaknesses of ADHD and Normal Behavior (SWAN) rating scale in Australia and Canada, and by Swanson, Nolan and Pelham, Teacher and Parent Rating Scale (SNAP) in Norway. The genetic similarity of SWAN and SNAP measures was assessed by LD regression. We also examined how genetic risk for ADHD symptoms correlated with neuropsychiatric phenotypes in adulthood, including schizophrenia, major depression disorder, bipolar disorder, Alzheimer’s disorder, subjective well-being, neuroticism and educational attainment. Overall, our preliminary results (N=3,445, SNAP data) suggest that the genetics of hyperactivity/impulsivity dimension in childhood show higher correlation with genetics of neuropsychiatric phenotypes in adulthood than that of childhood inattention, with strong contrasts between genetic correlations of hyperactivity/impulsivity and inattention with schizophrenia (h2=-0.115 and 0.0037), depressive symptoms (h2=0.483 and 0.278), subjective well-being (h2=-0.564 and -0.369), anxiety (h2=0.307 and 0.188) and Alzheimer's disease (h2=0.280 and 0.076). We will present the results from the full sample(N=11,784). Further exploration of how ADHD dimensions in childhood relate/lead to neuropsychiatric pathology in adulthood will aid our understanding of biological processes underlying ADHD symptomatology and, potentially, lead to better diagnosis, treatment and prevention options for ADHD.

Genetics of Attention Deficit Hyperactivity Disorder Across The Lifespan

Overall Abstract Attention Deficit Hyperactivity Disorder (ADHD) is the most commonly diagnosed childhood-onset neuropsychiatric condition, with impairing symptoms persisting into adulthood in the majority of cases. ADHD-diagnosed children, adolescents and adults share similar clinical features, co-morbidities and failures in major life domains. These associated problems increase the burden of disease and, consequently, global impairment, resistance to treatment and costs of illness. As most genetic studies on ADHD so far have been focusing on its childhood form only, there is limited knowledge about the genetics of ADHD at different ages, in clinical subgroups and across comorbid conditions. This symposium will present recent advances in our understanding of the genetics of ADHD and its major comorbid conditions across the lifespan. Speakers will address ADHD traits from a dimensional perspective using quantitative measures from national twin registry data, as well as unpublished genome wide molecular genetic data collected from large international multi-center clinical samples at different age groups. In this integrated symposium hosted by the International Multi-center persistent ADHD Collaboration (IMpACT), we will first present an updated review on ADHD heritability across the lifespan (presentation 1). We will then present a new international genome-wide association study of the adult form of ADHD (presentation 2), address genetic aspects of ADHD co-morbidity with adult obesity (presentation 3), and finally explore genetic correlations between ADHD dimensions in childhood and neuropsychiatric phenotypes in adulthood (presentation 4). As we gather more knowledge about ADHD, it is becoming clear that a full understanding of the disorder requires research from a lifetime perspective, integrating data from adults and children, using clinical samples as well as population registry data. Combination of different research traditions into a joint symposium will aid the exchange of information and future development of this important field.

M2 - ANALYZING THE ROLE OF COMMON EXOMIC VARIANTS ON MODULATING ADHD BEHAVIORS USING A BEHAVIORAL DYNAMIC APPROACH

Background Attention-Deficit/Hyperactivity Disorder (ADHD) is the most common behavioural disorder in school-aged children (3–6%). ADHD is characterized by developmentally inappropriate levels of attention, motor hyperactivity/impulsivity, or both. ADHD is a multifactorial highly heritable disorder, but its genetic underpinnings remain very difficult to unravel. This is mainly due to its multilayered phenotypic presentations (combination of several cognitive, emotional and motor traits), multiple environmental determinants and its complex genetic architecture. Our research group has been dissecting these various dimensions through a pharmaco-behavioural genetic study of ADHD while systematically collecting highly relevant environmental factors. Methods This unbiased and systematic approach will be deployed in two phases. First, we are using 179 children diagnosed with ADHD aged between 6–12 years and their parents to identify common exomic SNPs that are associated with ADHD or behavioural traits that are relevant for ADHD. This genotyping has already been completed through collaboration with the international ADHD genetic consortium. Preliminary results of this genotyping and its quality control indicate that there are over 20 000 eligible SNPs that can be analysed. In the second phase, 100 SNPs were selected according to a specific algorithm being developed (including criteria such as consistent association with ADHD across various behavioural relevant traits, functional relevance based on the role of the SNP in gene function or expression, the role of the gene in functional neural networks…) to be replicated in an independent sample of over 500 patients and their parents which are currently available in our laboratory. Results Preliminary results of this genotyping and its quality control indicate that there are over 20,000 eligible SNPs that can be analysed. In the second phase, 100 SNPs were selected according to a specific algorithm being developed (including criteria such as consistent association with ADHD across various behavioural relevant traits, functional relevance based on the role of the SNP in gene function or expression, the role of the gene in functional neural networks…). Discussion To our knowledge, this is the largest study attempting to unravel the genetic architecture of ADHD combining highly enriched behavioural dimensions of ADHD, pharmacological probes and a two-pronged whole exomic exploratory and a confirmatory steps. It is expected that this highly sophisticated approach will enable us to better understand the genetic of ADHD and its phenotypic variability.

The impact of depression, anxiety, neuroticism, and severity of Internet addiction symptoms on the relationship between probable ADHD and severity of insomnia among young adults

The aim of the present study was to evaluate the impact of depression, anxiety, neuroticism, and severity of Internet addiction symptoms (IAS) on the relationship between probable attention deficit/hyperactivity disorder (ADHD) and severity of insomnia among young adults. The study was conducted with online survey among 1010 volunteered university students in Ankara, people who are in the e-mail database of a company located in Istanbul that organizes e-sports tournaments and Turkish gamers from gaming forums. Scale scores were higher among the group with high probability of insomnia (n = 200, 19.8%). Also risk of high probability of insomnia was 2.7 times higher among those with probable ADHD. In linear regression analysis, both inattentiveness and hyperactivity/impulsivity dimensions of ADHD were related with the severity of insomnia, together with severities of anxiety, depression, neuroticism and IAS. Similarly, presence of probable ADHD was related with the severity of insomnia in ANCOVA, together with severities of anxiety, depression, neuroticism and IAS. These findings suggest that the presence of probable ADHD and the severity of ADHD symptoms are related with the severity of insomnia, even after controlling the depression, anxiety, neuroticism and IAS, which are all related with the severity of insomnia, among young adults.

Distinct dimensions defining the Adult ADHD Self-Report Scale: Implications for assessing inattentive and hyperactive/impulsive symptoms.

There has been growing interest in studying attention-deficit/hyperactivity disorder (ADHD) in adulthood as a result of research indicating that ADHD often persists into adulthood and frequently is comorbid with other psychiatric disorders. Adult ADHD symptoms are most commonly assessed via self-report, but prior research examining the structure of self-reported adult ADHD symptoms has yielded discrepant results. Explicating the factor structure of ADHD symptom measures is essential to determine if such self-report measures assess symptom dimensions showing distinctive relations with other psychopathology and psychosocial functioning. Consequently, we examined the structure of adult ADHD symptoms in a large sample of adult outpatients (N = 1,094). Symptoms were assessed via the Adult ADHD Self-Report Scale (ASRS; Kessler et al., 2005), which has become the most widely used self-report ADHD measure. Additionally, we extended prior research by examining the relations for emergent ADHD dimensions with other psychopathology and psychosocial impairment. Results indicated that the ASRS's items define a bifactor structure with specific dimensions of inattentiveness, motor hyperactivity/impulsivity, and verbal hyperactivity/impulsivity. Our results indicate that specific ADHD factors show distinctive relations in some ways. For example, verbal hyperactivity/impulsivity showed negative relations with major depressive disorder, whereas inattentiveness showed positive relations with major depression. These results highlight the need for future research determining the extent to which making distinctions among various ADHD symptom types (i.e., distinguishing motor and verbal hyperactivity/impulsivity) is empirically warranted and clinically useful. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Genetic and environmental contribution to the overlap between ADHD and ASD trait dimensions in young adults: a twin study.

Traits of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are strongly associated in children and adolescents, largely due to genetic factors. Less is known about the phenotypic and aetiological overlap between ADHD and ASD traits in adults. We studied 6866 individuals aged 20-28 years from the Swedish Study of Young Adult Twins. Inattention (IA) and hyperactivity/impulsivity (HI) were assessed using the WHO Adult ADHD Self-Report Scale-V1.1. Repetitive and restricted behaviours (RRB) and social interaction and communication (SIC) were assessed using the Autism-Tics, ADHD, and other Comorbidities inventory. We used structural equation modelling to decompose covariance between these ADHD and ASD trait dimensions into genetic and shared/non-shared environmental components. At the phenotypic level, IA was similarly correlated with RRB (r = 0.33; 95% Confidence Interval (CI) 0.31-0.36) and with SIC (r = 0.32; 95% CI 0.29-0.34), whereas HI was more strongly associated with RRB (r = 0.38; 95% CI 0.35-0.40) than with SIC (r = 0.24; 95% CI 0.21-0.26). Genetic and non-shared environmental effects accounted for similar proportions of the phenotypic correlations, whereas shared environmental effects were of minimal importance. The highest genetic correlation was between HI and RRB (r = 0.56; 95% 0.46-0.65), and the lowest was between HI and SIC (r = 0.33; 95% CI 0.23-0.43). We found evidence for dimension-specific phenotypic and aetiological overlap between ADHD and ASD traits in adults. Future studies investigating mechanisms underlying comorbidity between ADHD and ASD may benefit from exploring several symptom-dimensions, rather than considering only broad diagnostic categories.

Relationship of internet addiction severity with probable ADHD and difficulties in emotion regulation among young adults

The aim of the present study was to evaluate relationship of Internet addiction (IA) symptom severity with probable attention deficit/hyperactivity disorder (ADHD) and difficulties in emotion regulation, while controlling the effects of depression, anxiety and neuroticism. The study was conducted with online survey among 1010 volunteered participants of university students and/or amateur or professional gamers. Scale scores were higher among the group with high probability of ADHD (n = 190, 18.8%). In linear regression analysis, both Inattentiveness and hyperactivity/impulsivity dimensions of ADHD were related with the severity of IA symptoms, together with depression and non-accept dimension of the Difficulties in Emotion Regulation Scale (DERS). Similarly, presence of probable ADHD was related with the severity of IA symptoms in ANCOVA, together with depression, neuroticism and non-accept dimension of DERS. Participants were two different groups of non-clinical samples and all scales were self-rated. Also common comorbidities were not screened. Finally, since this study is cross-sectional the findings of this study cannot address the causal relationships among the primary constructs of interest. These findings suggest that the presence of probable ADHD is related with the severity of IA symptoms, together with the difficulties in emotion regulation, particularly non-accept dimension, depression and neuroticism among young adults.

Conners 3-Self-Report Scale: An empirical support to the dimensionality of the content scales.

The Conners' Rating Scales are one of the most used instruments for attention deficit/hyperactivity disorder (ADHD). Nonetheless, in the latest edition, the Inattention scale was not statistically supported. This study examined the dimensionality of the Italian version of the Conners 3-Self-Report scale testing both a five-factor structure including Inattention and a four-factor model combining Inattention and Learning Problems. Moreover, the generalizability of the detected structure through measurement invariance was verified. The Italian version of the scale was completed by 971 children (53% males, mean age: 12.76 years) randomly split in a calibration sample ( n = 464) and a validation sample ( n = 507). Confirmatory factor analyses detected a five-factor structure (i.e. Inattention, Hyperactivity/Impulsivity, Learning Problems, Defiance/Aggression, and Family Relations), and measurement invariance was confirmed. Findings provided statistical evidence for the Inattention subscale, supporting the Conners 3-Self-Report Scale as effectively aimed to assess the two dimensions of ADHD and its main comorbid difficulties.

Working Memory and Vigilance as Multivariate Endophenotypes Related to Common Genetic Risk for Attention-Deficit/Hyperactivity Disorder

Understanding the role of endophenotypes is essential for process models of psychopathology. This study examined which candidate cognitive endophenotypes statistically mediate common variant genetic risk for attention-deficit/hyperactivity disorder (ADHD). A case-control design using community-recruited volunteer children 7 to 11 years of age (n= 656, n= 435 ADHD), of whom 514 were of homogenous European ancestry for the primary models (n= 337 ADHD, 177 non-ADHD). Children were assessed with a multi-informant, best-estimate diagnostic procedure and laboratory measures of working memory, response inhibition, executive functioning, arousal/attention, temporal information processing, and processing speed. Latent variables were created for the candidate cognitive measures and for parent- and teacher-rated ADHD dimensions. Polygenic risk scores (PGS) were computed using a discovery sample of 20,183 individuals with ADHD and 35,191 controls from the Psychiatric Genetics Consortium. Cognitive measures that survived multiple testing correction for association with the PGS were evaluated for mediation with ADHD using structural equation models. Results were essentially identical in the homogeneous European ancestry subgroup (n= 514) and in the full sample (N= 656). For the European population, the PGS was associated with ADHD diagnosis (Nagelkerke R2= 0.045; β= 0.233, SE= 0.053, p= .000011) and multi-indicator dimensional ADHD latent variables by parent report (β= 0.185, SE= 0.043) and teacher report (β= 0.165, SE= 0.042). The PGS effect was statistically mediated by working memory (indirect effect, β= 0.101, SE= 0.029, 95% CI= 0.05, 0.16, p= .00049, 43% of genetic effect accounted for) and arousal/alertness (indirect effect β= 0.115, 95% CI= 0.04, 0.20, SE= 0.041, p= .005, 49% of genetic effect accounted for). This is the first clear demonstration from molecular genetic data that working memory and arousal regulation are promising cognitive endophenotypes for ADHD with regard to mediating genetic risk from common genetic variants.

Attention-Deficit/Hyperactivity Disorder and Very Preterm/Very Low Birth Weight: A Meta-analysis.

Although very preterm (VP), extremely preterm (EP), very low birth weight (VLBW), and extremely low birth weight (ELBW) newborns seem to have a higher risk of later attention-deficit/hyperactivity disorder (ADHD), the magnitude of the risk is not well-defined. To systematically review and meta-analyze the risk of VP/VLBW and EP/ELBW individuals to develop a ADHD categorical diagnosis or dimensional symptomatology compared with controls with normal weight and/or birth age. We used PsycINFO, Medline, Embase, and Cochrane databases. We selected cross-sectional, prospective, or retrospective studies with no time or language restriction. Independent reviewers screened and extracted data using predefined standard procedures. In 12 studies (N = 1787), researchers relying on a categorical diagnosis showed that both VP/VLBW and EP/ELBW subjects have a higher ADHD risk (odds ratio [OR] = 3.04 higher than controls; 95% confidence interval [CI] 2.19 to 4.21). In subgroup analyses, we demonstrated that the more extreme the cases, the higher the ORs (VP/VLBW: OR = 2.25 [95% CI 1.56 to 3.26]; EP/ELBW: OR = 4.05 [95% CI 2.38 to 6.87]). We drew data from 29 studies (N = 3504) on ADHD symptomatology and found significant associations with inattention (standardized mean difference [SMD] = 1.31, 95% CI 0.66 to 1.96), hyperactivity and impulsivity (SMD = 0.74, 95% CI 0.35 to 1.13), and combined symptoms (SMD = 0.55, 95% CI 0.42 to 0.68) when compared with controls. Heterogeneity was significantly high for all analyses involving the 3 ADHD dimensions. With our results, we provide evidence that VP/VLBW subjects have an increased risk of ADHD diagnosis and symptomatology compared with controls, and these findings are even stronger in the EP/ELBW group. Future researchers should address which risk factors related to prematurity or low birth weight lead to ADHD.