Attention-deficit/hyperactivity disorder (ADHD) and obesity are positively associated, with increasing evidence that they share genetic risk factors. Our aim was to examine whether these findings apply to both types of ADHD symptoms for female and male adolescents. We used data from 791 girl and 735 boy twins ages 16−17 years to examine sex-specific phenotypic correlations between the presence of ADHD symptoms and overweight/obese status. For correlations exceeding .20, we then fit bivariate twin models to estimate the genetic and environmental correlations between the presence of ADHD symptoms and overweight/obese status. ADHD symptoms and height/weight were parent- and self-reported, respectively. Phenotypic correlations were .30 (girls) and .08 (boys) for inattention and overweight/obese status and .23 (girls) and .14 (boys) for hyperactivity/impulsivity and overweight/obese status. In girls, both types of ADHD symptoms and overweight/obese status were highly heritable, with unique environmental effects comprising the remaining variance. Furthermore, shared genetic effects explained most of the phenotypic correlations in girls. Results suggest that the positive association of both types of ADHD symptoms with obesity may be stronger in girls than boys. Further, in girls, these associations may stem primarily from shared genetic factors.

Theoretical models of attention-deficit/hyperactivity disorder implicate neurocognitive dysfunction, yet neurocognitive functioning covers a range of abilities that may not all be linked with inattention. This study (a) investigated the single nucleotide polymorphism (SNP) heritability (h2SNP) of inattention and aspects of neurocognitive efficiency (memory, social cognition, executive function, and complex cognition) based on additive genome-wide effects; (b) examined if there were shared genetic effects among inattention and each aspect of neurocognitive efficiency; and (c) conducted an exploratory genome-wide association study to identify genetic regions associated with inattention. The sample included 3,563 participants of the Philadelphia Neurodevelopmental Cohort, a general population sample aged 8–21 years who completed the Penn Neurocognitive Battery. Data on inattention was obtained with the Kiddie Schedule of Affective Disorders (adapted). Genomic relatedness matrix restricted maximum likelihood was implemented in genome-wide complex trait analysis. Analyses revealed significant h2SNP for inattention (20%, SE = 0.08), social cognition (13%, SE = 0.08), memory (17%, SE = 0.08), executive function (25%, SE = 0.08), and complex cognition (24%, SE = 0.08). There was a positive genetic correlation (0.67, SE = 0.37) and a negative residual covariance (−0.23, SE = 0.06) between inattention and social cognition. No SNPs reached genome-wide significance for inattention. Results suggest specificity in genetic overlap among inattention and different aspects of neurocognitive efficiency.

Objectives: To examine the occurrence of and recovery from visual neglect-related symptoms with the focus on neglect laterality, ipsilateral orienting bias, and slowed processing speed in right hemisphere (RH) infarct patients during a 1-year follow-up. Furthermore, to propose guidelines for assessing processing speed alongside the Behavioural Inattention Test (BIT). Methods: We studied three RH patient groups: neglect (N+), mild left inattention (MLI+), and non-neglect (N−) patients, and healthy controls. The BIT with some additional analyses was conducted at the acute phase and at 6 and 12 months. Results: The N+ group’s BIT score increased and originally lateralized omissions became more evenly distributed during the follow-up. The N+ and MLI+ groups’ starting points were more rightward located than the healthy group’s at the acute phase and at 6, and partly at 12 months. Patient groups were slower than the controls in performing cancellation tests at the acute phase. The N+ and MLI+ groups remained slower than the controls throughout the follow-up. Conclusions: During the first year after RH infarct, originally left-sided manifestation of neglect shifted toward milder non-lateralized attentional deficit. Ipsilateral orienting bias and slowed processing speed appeared to be rather persistent neglect-related symptoms both in neglect patients and patients with initially milder inattention. We propose some effortless, tentative ways of examining processing speed and ipsilateral orienting bias alongside the BIT to better recognize these neglect-related symptoms, and highlight the need to assess and treat patients with initially milder inattention, who have been under-recognized and under-treated in clinical work. (JINS, 2018, 24, 617–628)

Right hemispheric damage (RHD) caused by strokes often induce attentional disorders such as hemispatial neglect. Most patients with neglect over time have a reduction in their ipsilesional spatial attentional bias. Despite this improvement in spatial bias, many patients remain disabled. The cause of this chronic disability is not fully known, but even in the absence of a directional spatial attentional bias, patients with RHD may have an impaired ability to accurately and precisely allocate their spatial attention. This inaccuracy and variable directional allocation of spatial attention may be revealed by repeated performance on a spatial attentional task, such as line bisection (LBT). Participants with strokes of their right versus left (LHD) hemisphere along with healthy controls (HC) performed 24 consecutive trials of 24 cm horizontal line bisections. A vector analysis of the magnitude and direction of deviations from midline, as well as their standard deviations (SD), were calculated. The results demonstrated no significant difference between the LHD, RHD and HC groups in overall spatial bias (mean bisection including magnitude and direction); however, the RHD group had a significantly larger variability of their spatial errors (SD), and made larger errors (from midline) than did the LHD and HC groups. There was a curvilinear relationship between the RHD participants’ performance variability and their severity of their inaccuracy. Therefore, when compared to HC and LHD, the RHD subjects’ performance on the LBT is more variable and inaccurate. (JINS, 2015, 21, 373–377)

Recently, there has been increased research into the etiology of the comorbidity between hyperactivity/inattention problems (HIP) and conduct problems (CP). However, the nature of the etiology of the comorbidity has remained unclear. Mothers of 507 pairs of twins, comprised of 221 monozygotic (MZ) and 286 dizygotic (DZ) twin pairs aged from 6 to 13 years (mean = 9.6 years; SD = 2.0 years), completed the HIP and the CP scale of the Strengths and Difficulties Questionnaire (SDQ) via a telephone interview. The phenotypic correlation between HIP and CP was 0.43 (p < .01). MZ and DZ twin correlations were, respectively, 0.48 (95%CI: 0.37–0.58) and 0.06 (95%CI: -0.06–0.19) for HIP and 0.38 (95%CI: 0.26–0.49) and 0.35 (95%CI: 0.25–0.45) for CP. The bivariate model-fitting results revealed additive genetic correlation of 1.0 (95% CI: 0.72–1.00), a complete overlap of additive genetic variance component between HIP and CP, supporting the importance of correlated additive genetic risk factors for the comorbid condition of HIP and CP. HIP was additionally influenced by non-additive genetic factors that did not contribute to the relationship between HIP and CP. There was a significant but moderate child-specific environmental correlation (r e = 0.37) between HIP and CP. CP was additionally influenced by shared family environmental influences. While the results of the present study are generally consistent with the findings from Western twin studies of the relationship between HIP and CP, they add a new finding to the extant literature by showing that it is additive rather than non-additive genetic factors that are responsible for the co-occurrence of HIP and CP.

Genome-wide association studies (GWAS) of attention-deficit/hyperactivity disorder (ADHD) offer the benefit of a hypothesis-free approach to measuring the quantitative effect of genetic variants on affection status. Generally the findings of GWAS relying on ADHD status have been non-significant, but the one study using quantitative measures of symptoms found SLC9A9 and SLC6A1 were associated with inattention and hyperactivity–impulsivity. Accordingly, we performed a GWAS using quantitative measures of each ADHD subtype measured with the Strengths and Weaknesses of ADHD and Normal Behaviour (SWAN) scale in two community-based samples. This scale captures the full range of attention and kinetic behavior; from high levels of attention and appropriate activity to the inattention and hyperactivity–impulsivity associated with ADHD within two community-based samples. Our discovery sample comprised 1,851 participants (mean age = 22.8 years [4.8]; 50.6% female), while our replication sample comprised 155 participants (mean age = 26.3 years [3.1]; 68.4% females). Age, sex, age × sex, and age2 were included as covariates and the results from each sample were combined using meta-analysis, then analyzed with a gene-based test to estimate the combined effect of markers within genes. We compare our results with markers that have previously been found to have a strong association with ADHD symptoms. Neither the GWAS nor subsequent meta-analyses yielded genome-wide significant results; the strongest effect was observed at rs2110267 (4.62 × 10−7) for symptoms of hyperactivity–impulsivity. The strongest effect in the gene-based test was for GPR139 on symptoms of inattention (6.40 × 10−5). Replication of this study with larger samples will add to our understanding of the genetic etiology of ADHD.

We examined whether externalizing problem behaviors (hyperactivity–impulsivity, aggressiveness, and inattention) predict illicit drug use independently, or whether their associations with drug use are mediated through cigarette smoking. We used a prospective longitudinal design within the FinnTwin12-17 study among Finnish adolescents with baseline at age 12 and follow-up surveys at ages 14 and 17. Path models were conducted with Mplus and included 1992 boys and 2123 girls. The outcome was self-reported ever use of cannabis or other illicit drugs at age 17. The predictors were: externalizing behaviors (hyperactivity–impulsivity, aggressiveness, and inattention) assessed by teachers and parents (age 12) and self-reported cigarette smoking (age 14). The findings differed across behavior studied. The association of hyperactivity–impulsivity with drug use was mostly mediated through earlier cigarette smoking. Concerning aggressiveness and inattention, the results were different among girls than boys. Among girls no significant mediation occurred, whereas among boys more consistent evidence on mediation was seen. Consistently in all models, the direct association of early cigarette smoking on drug use was strong and highly significant. We conclude that the associations of externalizing problem behaviors with illicit drug use are partially mediated through cigarette smoking. Although interventions targeting externalizing problem behaviors may protect adolescents from early onset smoking and subsequently experimenting with drugs, interventions to prevent cigarette smoking initiation are also important in reducing risk of later drug use.

This exploratory study investigated the screening of behaviour, and auditory processing and reading problems in the first school year, employing a sample of 74 children. A teacher behaviour risk index, which included (i) a Behaviour scale (internalising, externalising dimensions and inattention), (ii) a teacher Future Risk estimation, was found to be reliable and a valid predictor of behaviour, together with a parent-based behaviour scale, against the Personal-Social Behaviour sub-scale of the Pupil Rating Scale-Revised. Adding the teacher-based Behaviour scale to the child-based Performance Indicators in the Primary School (PIPS) did not assist reading assessment, however the PIPS scale was confirmed as a valid reading predictor. A teacher-based Central Auditory Processing Disorder (CAPD) scale was significantly correlated to teacher-based Inattention and Behaviour and, with the teacher-based Behaviour scale, significantly predicted reading. On its own it predicted reading better than phonological awareness. It was suggested that child behaviour, CAPD and reading profiles could facilitate joint parent-teacher at-risk referrals in Year 1, including mental health. Assistive listening devices were recommended to aid children's auditory processing. The study needs replication with larger samples.

Reviews of the literature on attention-deficit/hyperactivity disorder (ADHD) typically begin early in the twentieth century with the descriptions provided by paediatrician George Still. Physician Alexander Crichton, however, described all of the essential features of the Inattentive subtype of ADHD more than a century earlier than Still. This article presents a short biography of Crichton, looks at his 1798 publication describing attentional disorders in otherwise healthy individuals, contrasts his medical writing with the moralism of Still, and shows how his thoughts and observations are very much in accord with DSM-IV criteria for the Inattentive subtype of ADHD.

This study reports a cognitive-behavioural intervention implemented to increase academic performance of an 11-year-old boy with Attention-Deficit Disorder/Without Hyperactivity. The child was trained in the use of positive self-talk to reduce the cognitive distortions and deficiencies associated with his symptoms. Reports from the child, his parent and his teacher, together with objective measures and observations, were used to assess the efficacy of treatment in reducing symptoms and increasing academic performance. Results suggest an increase in academic performance with a greater improvement in productivity rather than in accuracy. These improvements could be related to the decreases in the problematic symptoms of in attention and anxiety. Unconditional conclusions cannot be drawn, however, about the effect of the intervention on impulsivity, because of the difficulties found in measuring this construct Improvements to overcome this problem and other modifications that may improve the overall validity of future studies are suggested.