Genetic Support for the Dual Nature of Attention Deficit Hyperactivity Disorder: Substantial Genetic Overlap Between the Inattentive and Hyperactive–impulsive Components

Objective Attention deficit hyperactivity disorder (ADHD) is a common, complex and highly heritable disorder, characterised by inattentive, impulsive and overactive behaviour. Evidence for the heritability of ADHD measures in twin population samples has come from the analysis of total scores that combine inattentive and hyperactive–impulsive symptoms subscales. This study investigated, in a community sample, the aetiology of ADHD-like traits and the aetiological overlap between the two dimensions that define the ADHD disorder. Materials and Methods Parents of 6,222 approximately 8-year-old twin pairs from the Twins Early Development Study (TEDS) population sample completed the two subscales of the Conners’ 18-item DSMIV checklist, a screening instrument for ADHD symptoms. Results Both subscales were highly heritable (hyperactive–impulsive: 88%; inattentive: 79%). Bivariate genetic modelling indicated substantial genetic overlap between the two components; however, there were significant independent genetic effects. Conclusions These findings suggest that many genes associated with the hyperactivity–impulsivity dimension will also be associated with the inattentive dimension but that there is significant genetic heterogeneity as well. These results provide genetic support for combining the two behavioural dimensions that define ADHD, but also suggest that some symptom-specific genes will also be identified. Correspondence and reprint requests to Gráinne McLoughlin, SGDP Centre, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, Tel: +44(0) 207-848-5261; Email: g.mcloughlin@iop.kcl.ac.uk.     

Seemingly Anomalous WISC-IV Full Scale IQ Scores in the American and Canadian Standardization Samples

The American and Canadian standardization samples for the fourth edition of the Wechsler Intelligence Scale for Children were used to ascertain the prevalence of “seemingly anomalous” Full Scale IQ (FSIQ) scores for all possible sums of scaled scores combinations of the Verbal Comprehension Index, Perceptual Reasoning Index, Working Memory Index, and Processing Speed Index. About 1% of FSIQ scores in both samples were anomalous (that is, fell outside the range of the four indices). Interestingly, the prevalence of anomalous scores was higher at the extremes of the FSIQ distribution. Moreover, anomalous FSIQ scores occurring above or below the mean of the FSIQ distribution (that is, 100) were larger or smaller, respectively, than any of the four indices. Furthermore, if the range of the four indices did contain the FSIQ (the non-anomalous case), when the FSIQ was below or above 100 it tended to be located distally in the half-segment of the range furthest below or above 100, respectively. A non-technical intuitive analogy from Olympic sports and a statistical explanation for the findings are provided. Important implications for practitioners are also presented. Portions of this paper were presented March 17, 2006 at the 20th annual Joseph R. Royce Research Conference, Department of Psychology, University of Alberta, Edmonton, Alberta.     

Generalizability in the Mediation Effects of Parental Expectations on Children’s Cognitive Ability and Self-concept

Previous research involving Hong Kong Chinese parents and their children showed that parental home involvement, beliefs of their children’s cognitive ability and their expectations for academic achievement mediated the relationship between their children’s cognitive ability and school achievement scores. This mediation effect was interpreted as the cognitive-affect model of academic achievement. The current research confirms the generalizability of the findings and tests the hypothesis that there are cultural differences in the mediation effects with the inclusion of non-Chinese students and their parents as a comparison group. The responses from 103 Chinese speaking (CS) and 163 non-Chinese speaking (NCS) primary students and parents from two schools in Hong Kong were analyzed using structural equation modeling. Student measures included self-concept, cognitive ability and academic achievement in mathematics, English and Chinese. Parent measures included home involvement, beliefs of their child’s cognitive ability and expectations of academic success. Initial model showed that parental expectations mediate the link between cognitive ability and academic achievement for both CS and NCS groups, with parental involvement predicting English achievement for only the NCS group. After the inclusion of academic self-concept, the model showed that CS parental expectations also mediate the link between self-concept and academic achievement. However, the model showed that the parental expectations of NCS play a lesser role in mediating the link between academic self-concept and their children’s academic achievement. Despite the differences, the results provide evidence for the generalizability of the cognitive-affect model.     

The impact of the “Attachment and Biobehavioural Catch-Up” program on attachment related parent behavior—A systematic review

“Attachment and Biobehavioural Catch-Up” (ABC) is a 10 session home visiting program, grounded in attachment theory. It aims to improve child emotion regulation, attachment and behavioral outcomes through changing caregivers’ attachment related behaviors. There is increasing evidence with respect to the effectiveness of ABC in producing positive child outcomes, but the intervention's direct effect on parent outcomes remains unclear. This review examined the association of ABC with attachment related parent outcomes. The PubMed, EMBASE, PyschINFO and SCOPUS databases were searched for relevant studies in August 2021, and again in April 2022. The eligibility criteria for included studies were (1) infants aged 0–27 months at time of the ABC intervention, (2) “at risk” parents, (3) controlled trials published in peer-reviewed journals and (4) utilized a measure of attachment related parent outcomes. Eleven eligible studies were included. The findings showed ABC had a significant small to medium effect on a variety of attachment related parent outcomes among parents presenting with multiple psychosocial risk factors. “Sensitivity” was measured most frequently, with small to medium main effect sizes recorded at follow-up, compared to controls. Implications for the clinical effectiveness of the ABC program in community settings are discussed. Future research should clarify who ABC is most effective for and how it compares to similar interventions.     

Use of the "Mental Health Inventory - 5" with Portuguese 10-15 years old

The present study describes the psychometric properties of the Portuguese version of the Mental Health Inventory-5 for use with young adolescents. A sample of 367 Portuguese students (aged 10-15 years) completed the Portuguese-language versions of Mental Health Inventory-5 (MHI-5; Berwick et al., 1991), Children's Hope Scale (CHS; Snyder et al., 1997), Students' Life Satisfaction Scale (SLSS; Huebner, 1991a), and Global Self-Worth Sub-scale (Harter, 1985). Analysis of readability, reliability (internal consistency and 1-year stability), factor structure, and criterion-related validity suggested that the MHI-5 can be appropriately used in this age group. Implications of the findings are discussed.     

Do girls and boys perceive themselves as equally engaged in school? The results of an international study from 12 countries

This study examined gender differences in student engagement and academic performance in school. Participants included 3420 students (7th, 8th, and 9th graders) from Austria, Canada, China, Cyprus, Estonia, Greece, Malta, Portugal, Romania, South Korea, the United Kingdom, and the United States. The results indicated that, compared to boys, girls reported higher levels of engagement in school and were rated higher by their teachers in academic performance. Student engagement accounted for gender differences in academic performance, but gender did not moderate the associations among student engagement, academic performance, or contextual supports. Analysis of multiple-group structural equation modeling revealed that perceptions of teacher support and parent support, but not peer support, were related indirectly to academic performance through student engagement. This partial mediation model was invariant across gender. The findings from this study enhance the understanding about the contextual and personal factors associated with girls' and boys' academic performance around the world.     

I act,therefore I am: Athletic identity and the health action process approach predict sport participation among individuals with acquired physical disabilities

ObjectiveThe study had two objectives 1) to test the fit of the Health Action Process Approach (HAPA) model for sport participation among individuals with acquired physical disabilities and 2) to estimate the extent to which athletic identity predicts intentions to engage in sport within the context of HAPA.DesignProspective cohort of 82 women and 19 men with acquired permanent disabilities (M_age = 44.0; M_{years post-injury} = 16.2; %_{in sport} = 61.7%).MethodAll HAPA indicators and athletic identity were assessed at baseline and sport participation was assessed using the Leisure Time Physical Activity Questionnaire for People with Spinal Cord Injury two weeks later. Structural equation modelling was used to test the HAPA model.ResultsThe HAPA constructs explained 15% of the variance in sport participation and 18% of the variance when athletic identity was added to the model. Instrumental (β = .21), affective (β = .15), and negative outcome expectancies (β = ?.20) were significant predictors of intentions to participate in sport, as was athletic identity (β = .25). Intentions to participate in sport significantly predicted planning (β = .54) yet there was no direct relationship between planning and sport participation (β = ?.008; p > .05). When the relationship between planning and maintenance self-efficacy was reversed, planning had a significant indirect effect on sport participation through maintenance self-efficacy (β = .33).ConclusionThe HAPA model is a good predictive model for sport participation among those with acquired physical disabilities; furthermore, athletic identity accounts for additional variance in sport participation. These constructs can be valuable components of sport promotion programs for this population.