A review of executive function deficits in autism spectrum disorder and attention-deficit/hyperactivity disorder

The bidirectional association between sleep problems and autism spectrum disorder: a population-based cohort study

Background

Sleep difficulties are prevalent in children with autism spectrum disorder (ASD). The temporal nature of the association between sleep problems and ASD is unclear because longitudinal studies are lacking. Our aim is to clarify whether sleep problems precede and worsen autistic traits and ASD or occur as a consequence of the disorder.

Methods

Repeated sleep measures were available at 1.5, 3, 6, and 9 years of age in 5151 children participating in the Generation R Study, a large prospective birth cohort in the Netherlands. Autistic traits were determined with the Pervasive Developmental Problems score (PDP) of the Child Behavior Checklist (CBCL) at 1.5 and 3 years and the Social Responsiveness Scale (SRS) at 6 years. This cohort included 81 children diagnosed with ASD.

Results

Sleep problems in early childhood were prospectively associated with a higher SRS score, but not when correcting for baseline PDP score. By contrast, a higher SRS score and an ASD diagnosis were associated with more sleep problems at later ages, even when adjusting for baseline sleep problems. Likewise, a trajectory of increasing sleep problems was associated with ASD.

Conclusions

Sleep problems and ASD are not bidirectionally associated. Sleep problems do not precede and worsen autistic behavior but rather co-occur with autistic traits in early childhood. Over time, children with ASD have an increase in sleep problems, whereas typically developing children have a decrease in sleep problems. Our findings suggest that sleep problems are part of the construct ASD.

Metacognitive Aspects of Executive Function Are Highly Associated with Social Functioning on Parent-Rated Measures in Children with Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is characterized by social dysfunction. Even though executive dysfunction has been recognized as important in understanding ASD, the findings are inconsistent. This might be due to different definitions of executive function (EF), which part of EF that has been studied, structured vs. unstructured tasks, inclusion of different moderators (age, IQ, sex) and different diagnostic categories within the spectrum. The main finding is that people with ASD have more EF difficulties than normal controls and more difficulties on open-end tasks than on structured cognitive tasks. Since some EF difficulties may not be observable in a laboratory setting, informant measures might have higher ecological validity than neuropsychological tests. Evidence suggests that executive dysfunctions are associated with social impairments, but few studies have investigated the details of this relationship, and it remains unclear what types of EF deficits are relevant for the social problems of individuals with ASD. Here we investigated which EF domains were associated with various domains of social function on parent-rated measures. A total of 86 children and adolescents with a diagnosis of ASD were included and tested for general cognitive abilities. Parents completed the Behavior Rating Inventory of Executive Function (BRIEF) and the Social Responsiveness Scale (SRS). Multiple regression analysis revealed significant associations between SRS scores and age, sex, total IQ and the BRIEF indexes. The Metacognition Index from the BRIEF added significantly to the prediction of the SRS total score and the subscales Social Communication, Social Motivation and Autistic Mannerisms. The findings suggest that metacognitive aspects of EF are of particular importance for social abilities in children and adolescents with ASD. Earlier research has shown that typically developing (TD) children have a different relationship between EF and social function than children with ASD. They found that in TD children the EF domain related to behavioral regulation was most important to social function. The results from the current study may have implications for understanding the cognitive components of the social problems that define ASD, and may be relevant in developing more targeted clinical EF interventions related to core ASD dysfunctions.

Cross-Disorder Cognitive Impairments in Youth Referred for Neuropsychiatric Evaluation

OBJECTIVES

Studies suggest that impairments in some of the same domains of cognition occur in different neuropsychiatric conditions, including those known to share genetic liability. Yet, direct, multi-disorder cognitive comparisons are limited, and it remains unclear whether overlapping deficits are due to comorbidity. We aimed to extend the literature by examining cognition across different neuropsychiatric conditions and addressing comorbidity.

METHODS

Subjects were 486 youth consecutively referred for neuropsychiatric evaluation and enrolled in the Longitudinal Study of Genetic Influences on Cognition. First, we assessed general ability, reaction time variability (RTV), and aspects of executive functions (EFs) in youth with non-comorbid forms of attention-deficit/hyperactivity disorder (ADHD), mood disorders and autism spectrum disorder (ASD), as well as in youth with psychosis. Second, we determined the impact of comorbid ADHD on cognition in youth with ASD and mood disorders.

RESULTS

For EFs (working memory, inhibition, and shifting/ flexibility), we observed weaknesses in all diagnostic groups when participants' own ability was the referent. Decrements were subtle in relation to published normative data. For RTV, weaknesses emerged in youth with ADHD and mood disorders, but trend-level results could not rule out decrements in other conditions. Comorbidity with ADHD did not impact the pattern of weaknesses for youth with ASD or mood disorders but increased the magnitude of the decrement in those with mood disorders.

CONCLUSIONS

Youth with ADHD, mood disorders, ASD, and psychosis show EF weaknesses that are not due to comorbidity. Whether such cognitive difficulties reflect genetic liability shared among these conditions requires further study. (JINS, 2018, 24, 91-103).

Development of the Supported Employment, Comprehensive Cognitive Enhancement, and Social Skills program for adults on the autism spectrum: Results of initial study

The population of adults on the autism spectrum continues to increase, and vocational outcomes are particularly poor. Longitudinal studies of adults with autism spectrum and without intellectual disability have shown consistent and persistent deficits across cognitive, social, and vocational domains, indicating a need for effective treatments of functional disabilities as each impact employment. This initial pilot study is an open trial investigation of the feasibility, acceptability, and initial estimates of outcomes for the newly developed Supported Employment, Comprehensive Cognitive Enhancement, and Social Skills intervention, a manualized "soft skills" curriculum, to enhance both cognitive and social development in adults with autism spectrum. A total of eight adults with autism spectrum, without intellectual disability (78% males), participated in the study. Results support the original hypothesis that adults with autism spectrum can improve both cognitive (i.e. executive functioning) and social cognitive (i.e. social thinking and social communication) abilities. Further Supported Employment, Comprehensive Cognitive Enhancement, and Social Skills was found to be feasible, acceptable, and highly satisfactory for participants and parents. Employment rates more than doubled post-intervention, with an increase from 22% to 56% of participants employed. Conclusion is that Supported Employment, Comprehensive Cognitive Enhancement, and Social Skills has promise as an intervention that can be easily embedded into exiting supported employment vocational training programs to improve cognitive, social, and vocational outcomes.

Early executive dysfunction in ASD: Simple versus complex skills

Despite the strong evidence of executive function (EF) impairment in Autism Spectrum Disorder (ASD), findings in the preschool period have been inconsistent. Whereas some research has supported an early deficit, many studies have not found early differences in EF. The present study assessed simple and complex components of three EF abilities: working memory, inhibition, and shifting, using a novel battery, the Preschool EF Battery (PEFB; Garon, Smith & Bryson, Child Neuropsychology, 20, 713-736, 2014). Previous research has indicated that the PEFB is sensitive to age differences in typically developing (TD) children aged 18-60 months. Current participants were 34 preschoolers (M = 54.79 months) diagnosed with ASD and 255 TD preschoolers (M = 42.98 months). Results indicated significant differences between the two groups in the three EF abilities, but specific findings were moderated by mental and chronological age. The findings highlight the importance of testing simpler EF skills in very young children with ASD. Autism Res 2018, 11: 318-330. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

Given that executive functions (EF) have been found to predict various outcomes such as academic ability and occupational success, sensitive early assessment is important. The current study suggests the presence of early EF deficits in preschool children with autism spectrum disorder. The study highlights the importance of considering how EF develops during early life in typically developing children in order to design sensitive EF measures.

Specificity of executive function and theory of mind performance in relation to attention-deficit/hyperactivity symptoms in autism spectrum disorders

Background

Individuals with autism spectrum disorder (ASD) frequently demonstrate symptoms of attention-deficit/hyperactivity disorder (ADHD). Previous findings in children with ASD have suggested that these symptoms are associated with an impairment in executive function (EF) abilities. However, studies rarely considered this association within a single framework that controls for other related factors such as Theory of Mind (ToM) abilities and ASD symptoms.

Methods

We used structural equation modeling to explore the relations among EF, ToM, and symptoms of ASD and ADHD, using data from a population-based sample of 100 adolescents with ASD and full-scale IQ ≥ 50 (the Special Needs and Autism Project (SNAP) cohort). The study used a multi-measure and multi-informant approach, where performance of inhibition, planning, switching, and working memory tasks indexed EF and performance on tasks involving mentalizing indexed ToM. Measures of ASD and ADHD symptoms included parent and teacher reports and direct observation of the children. Shared source of symptom reporting was accounted for with a parental rating latent factor indexed by symptom measures reported by parents.

Results

Impairments in EF abilities were specifically associated with ADHD symptoms while impaired ToM was specifically associated with ASD symptoms, when accounting for the associations of each cognitive domain with the other factors. ASD and ADHD symptom latent factors were also correlated, but this association became nonsignificant once the shared source of reporting from parents was accounted for and within a model that also controlled for the correlated pathway between EF and ToM factors. The specific relations between the cognitive domains and behavioral symptoms remained even after controlling for IQ.

Conclusions

In this ASD sample, symptoms of ADHD and ASD are underpinned by separate cognitive domains. The association between EF and ToM impairments is a likely partial explanation for the co-occurrence of ADHD symptoms in ASD, but the role of shared reporting effects is also important and supports the inclusion of independent informants and objective measures in future research.

Atypical age-dependency of executive function and white matter microstructure in children and adolescents with autism spectrum disorders

Executive function (EF) performance is associated with measurements of white matter microstructure (WMS) in typical individuals. Impaired EF is a hallmark symptom of autism spectrum disorders (ASD) but it is unclear how impaired EF relates to variability in WMS. Twenty-one male youth (8-18 years) with ASD and without intellectual disability and twenty-one typical male participants (TP) matched for age, intelligence quotient, handedness, race and parental socioeconomic status were recruited. Five EF domains were assessed and several DTI-based measurements of WMS [fractional anisotropy (FA), mean diffusivity (MD) and radial diffusivity (RD)] were estimated for eighteen white matter tracts. The ASD group had lower scores for attention (F = 8.37, p = 0.006) and response inhibition (F = 13.09, p = 0.001). Age-dependent changes of EF performance and WMS measurements were present in TP but attenuated in the ASD group. The strongest diagnosis-by-age effect was found for forceps minor, left anterior thalamic radiation and left cingulum angular bundle (all p's ≤ 0.002). In these tracts subjects with ASD tended to have equal or increased FA and/or reduced MD and/or RD at younger ages while controls had increased FA and/or reduced MD and/or RD thereafter. Only for TP individuals, increased FA in the left anterior thalamic radiation was associated with better response inhibition, while reduced RD in forceps minor and left cingulum angular bundle was related to better problem solving and working memory performance respectively. These findings provide novel insight into the age-dependency of EF performance and WMS in ASD, which can be instructive to cognitive training programs.

Impact of juvenile chronic stress on adult cortico-accumbal function: Implications for cognition and addiction

Repeated exposure to stress during childhood is associated with increased risk for neuropsychiatric illness, substance use disorders and other behavioral problems in adulthood. However, it is not clear how chronic childhood stress can lead to emergence of such a wide range of symptoms and disorders in later life. One possible explanation lies in stress-induced disruption to the development of specific brain regions associated with executive function and reward processing, deficits in which are common to the disorders promoted by childhood stress. Evidence of aberrations in prefrontal cortex and nucleus accumbens function following repeated exposure of juvenile (pre- and adolescent) organisms to a variety of different stressors would account not only for the similarity in symptoms across the wide range of childhood stress-associated mental illnesses, but also their persistence into adulthood in the absence of further stress. Therefore, the goal of this review is to evaluate the current knowledge regarding disruption to executive function and reward processing in adult animals or humans exposed to chronic stress over the juvenile period, and the underlying neurobiology, with particular emphasis on the prefrontal cortex and nucleus accumbens. First, the role of these brain regions in mediating executive function and reward processing is highlighted. Second, the neurobehavioral development of these systems is discussed to illustrate how juvenile stress may exert long-lasting effects on prefrontal cortex-accumbal activity and related behavioral functions. Finally, a critical review of current animal and human findings is presented, which strongly supports the supposition that exposure to chronic stress (particularly social aggression and isolation in animal studies) in the juvenile period produces impairments in executive function in adulthood, especially in working memory and inhibitory control. Chronic juvenile stress also results in aberrations to reward processing and seeking, with increased sensitivity to drugs of abuse particularly noted in animal models, which is in line with greater incidence of substance use disorders seen in clinical studies. These consequences are potentially mediated by monoamine and glutamatergic dysfunction in the prefrontal cortex and nucleus accumbens, providing translatable therapeutic targets. However, the predominant use of male subjects and social-based stressors in preclinical studies points to a clear need for determining how both sex differences and stressor heterogeneity may differentially contribute to stress-induced changes to substrates mediating executive function and reward processing, before the impact of chronic juvenile stress in promoting adult psychopathology can be fully understood.

Age-related differences in inhibitory control and memory updating in boys with Asperger syndrome

Deficits in specific executive domains are highly prevalent in autism spectrum disorder; however, age-related improvements in executive functions (reflecting prefrontal maturational changes) have been reported even in individuals diagnosed with autism. The current study examined two components of cognitive flexibility (inhibition of prepotent responses and memory monitoring/updating) by using a random-motor-generation task (MPT) in a group of 23 boys with Asperger syndrome (AS) and 23 matched healthy controls. We found poorer inhibition and more repetitive responses in younger AS children solely, but comparable memory monitoring/updating skills across groups. Overall, our findings correspond well with previous studies and reveal that even in AS specific EFs may improve with age and, thus, call for a more differentiated view of executive (dys) function profiles in children diagnosed with AS. Tests such as the random-motor-generation task may help to disentangle more specific processes of executive deficits in autism spectrum disorder as compared to the more classical tests.

The association between theory of mind, executive function, and the symptoms of autism spectrum disorder

It has been strongly argued that atypical cognitive processes in autism spectrum disorder (ASD) contribute to the expression of behavioural symptoms. Comprehensive investigation of these claims has been limited by small and unrepresentative sample sizes and the absence of wide-ranging task batteries. The current study investigated the cognitive abilities of 100 adolescents with ASD (mean age = 15 years 6 months), using 10 tasks to measure the domains of theory of mind (ToM) and executive function (EF). We used structural equation modelling as a statistically robust way of exploring the associations between cognition and parent-reported measures of social communication and restricted and repetitive behaviours (RRBs). We found that ToM ability was associated with both social communication symptoms and RRBs. EF was a correlate of ToM but had no direct association with parent-reported symptom expression. Our data suggest that in adolescence ToM ability, but not EF, is directly related to autistic symptom expression. Autism Res 2018, 11: 95-109. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

The behaviours that are common to autism spectrum disorder (ASD) have been linked to differences in thinking ability. We assessed autistic adolescents and found that social communication difficulties and the presence of restricted and repetitive behaviours related to difficulties in understanding other peoples' minds (theory of mind). In contrast, these behaviours were not associated with the general thinking abilities involved in planning and executing tasks (executive function).

Influencia del riesgo social en la teoría de la mente y funciones ejecutivas de adolescentes colombianos

El objetivo del presente estudio fue determinar la relación que existe entre las Funciones Ejecutivas (FE) y la Teoría de la Mente (ToM) en población colombiana en condición de riesgo social. Participaron 78 adolescentes (41 en riesgo social y 37 controles) entre los 13 y 16 años. Se administraron el Test de Palabras y Colores de Stroop, el Test de la Pirámide de México y el Test de Falso Paso para evaluar Control Inhibitorio, Planificación y ToM, respectivamente. A pesar de que no se encontraron diferencias significativas en los procesos ejecutivos de control inhibitorio y planificación, los controles mostraron tener mejor desempeño en la prueba de ToM (p<0,05). Adicionalmente, mientras que al interior del grupo sin riesgo social se observó una relación entre la ToM y los procesos ejecutivos evaluados (ps<0,05), sin embargo, al interior del grupo en riesgo social estos procesos no están relacionados. Se concluye que el entorno de riesgo social parece no afectar las habilidades ejecutivas de control inhibitorio y planificación pero sí la habilidad para realizar inferencias acerca de los estados mentales de los otros. De esta manera, un entorno de riesgo social es un factor ambiental que parece disociar el proceso de desarrollo de la cognición social y de los procesos ejecutivos en adolescentes, desarrollo que debería darse de manera paralela.

Event-Related Potentials in a Cued Go-NoGo Task Associated with Executive Functions in Adolescents with Autism Spectrum Disorder; A Case-Control Study

Executive functions are often affected in autism spectrum disorders (ASD). The underlying biology is however not well known. In the DSM-5, ASD is characterized by difficulties in two domains: Social Interaction and Repetitive and Restricted Behavior, RRB. Insistence of Sameness is part of RRB and has been reported related to executive functions. We aimed to identify differences between ASD and typically developing (TD) adolescents in Event Related Potentials (ERPs) associated with response preparation, conflict monitoring and response inhibition using a cued Go-NoGo paradigm. We also studied the effect of age and emotional content of paradigm related to these ERPs. We investigated 49 individuals with ASD and 49 TD aged 12-21 years, split into two groups below (young) and above (old) 16 years of age. ASD characteristics were quantified by the Social Communication Questionnaire (SCQ) and executive functions were assessed with the Behavior Rating Inventory of Executive Function (BRIEF), both parent-rated. Behavioral performance and ERPs were recorded during a cued visual Go-NoGo task which included neutral pictures (VCPT) and pictures of emotional faces (ECPT). The amplitudes of ERPs associated with response preparation, conflict monitoring, and response inhibition were analyzed. The ASD group showed markedly higher scores than TD in both SCQ and BRIEF. Behavioral data showed no case-control differences in either the VCPT or ECPT in the whole group. While there were no significant case-control differences in ERPs from the combined VCPT and ECPT in the whole sample, the Contingent Negative Variation (CNV) was significantly enhanced in the old ASD group (p = 0.017). When excluding ASD with comorbid ADHD we found a significantly increased N2 NoGo (p = 0.016) and N2-effect (p = 0.023) for the whole group. We found no case-control differences in the P3-components. Our findings suggest increased response preparation in adolescents with ASD older than 16 years and enhanced conflict monitoring in ASD without comorbid ADHD during a Go-NoGo task. The current findings may be related to Insistence of Sameness in ASD. The pathophysiological underpinnings of executive dysfunction should be further investigated to learn more about how this phenomenon is related to core characteristics of ASD.

Social Cognition in Children with High-Functioning Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder. Associations with Executive Functions

Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are neurodevelopmental disorders characterized by social impairments. The first objective of this study was to analyze social cognition deficits of children with ADHD, high-functioning ASD (HFASD), and typical development (TD) in their performance on explicit and applied measures of theory of mind (ToM). The second objective was to investigate the relationships between executive functions and social cognition in HFASD and ADHD. One hundred and twenty-six 7- to 11-year old children, 52 with HFASD, 35 with ADHD, and 39 with TD, performed the NEPSY-II social perception subtests. Parents estimated their children's ToM skills using the Theory of Mind Inventory (ToMI). Teacher-reported data from the Behavior Rating Inventory of Executive Function (BRIEF) were also obtained. The HFASD and ADHD groups showed worse performance on the verbal ToM task than the TD group, and only the performance of the HFASD group was significantly lower than the TD group on the contextual ToM task. Parents also estimated that the HFASD group had more difficulties on the applied ToM than the ADHD and TD groups. Furthermore, there is a different executive function-theory of mind link in the HFASD and ADHD groups: behavioral regulation processes such as inhibition and emotional control are more associated with social cognition in children with ADHD, whereas metacognitive processes such as initiation and planning have a strong association with social cognition in children with HFASD. These findings have implications for understanding social perception deficits in neurodevelopmental disorders, highlighting the need for early intervention.

The Davida Teller Award Lecture, 2016: Visual Brain Development: A review of "Dorsal Stream Vulnerability"-motion, mathematics, amblyopia, actions, and attention

Research in the Visual Development Unit on "dorsal stream vulnerability' (DSV) arose from research in two somewhat different areas. In the first, using cortical milestones for local and global processing from our neurobiological model, we identified cerebral visual impairment in infants in the first year of life. In the second, using photo/videorefraction in population refractive screening programs, we showed that infant spectacle wear could reduce the incidence of strabismus and amblyopia, but many preschool children, who had been significantly hyperopic earlier, showed visuo-motor and attentional deficits. This led us to compare developing dorsal and ventral streams, using sensitivity to global motion and form as signatures, finding deficits in motion sensitivity relative to form in children with Williams syndrome, or perinatal brain injury in hemiplegia or preterm birth. Later research showed that this "DSV" was common across many disorders, both genetic and acquired, from autism to amblyopia. Here, we extend DSV to be a cluster of problems, common to many disorders, including poor motion sensitivity, visuo-motor spatial integration for planning actions, attention, and number skills. In current research, we find that individual differences in motion coherence sensitivity in typically developing children are correlated with MRI measures of area variations in parietal lobe, fractional anisotropy (from TBSS) of the superior longitudinal fasciculus, and performance on tasks of mathematics and visuo-motor integration. These findings suggest that individual differences in motion sensitivity reflect decision making and attentional control rather than integration in MT/V5 or V3A. Its neural underpinnings may be related to Duncan's "multiple-demand" (MD) system.

Using inclusive sampling to highlight specific executive functioning impairments in autism spectrum disorder

Objectives: The aim of the study is to help identify the nature of impaired executive functioning (EF) in children with autism spectrum disorder (ASD). It is also argued that participant sampling by age alone should inform experimental research on EF, as selection through IQ matching may weaken any experimental effects. Methods: Sixteen children with ASD across a wide range of Nonverbal IQ (NVIQ) and 16 neurotypical control children matched on age alone were given two different types of computerized sequencing game. Both required top-down organization, but in one case the sequence had to be self-generated while in the second it had to be learned and strictly followed. Measures of learning success in relation to NVIQ, and information processing demands were made. Results: Children with ASD were significantly impaired on the first task only, especially when the processing demands were increased. The effects were particularly pronounced for children with below average NVIQ. Conclusions: The study indicates a selective problem with self-organized sequencing in ASD with implications for certain real world contexts, but also points to a need for more inclusive sampling of children in order to fully expose specific executive impairments in autism spectrum disorder.

No genetic association between attention-deficit/hyperactivity disorder (ADHD) and Parkinson's disease in nine ADHD candidate SNPs

Attention-deficit/hyperactivity disorder (ADHD) and Parkinson's disease (PD) involve pathological changes in brain structures such as the basal ganglia, which are essential for the control of motor and cognitive behavior and impulsivity. The cause of ADHD and PD remains unknown, but there is increasing evidence that both seem to result from a complicated interplay of genetic and environmental factors affecting numerous cellular processes and brain regions. To explore the possibility of common genetic pathways within the respective pathophysiologies, nine ADHD candidate single nucleotide polymorphisms (SNPs) in seven genes were tested for association with PD in 5333 cases and 12,019 healthy controls: one variant, respectively, in the genes coding for synaptosomal-associated protein 25 k (SNAP25), the dopamine (DA) transporter (SLC6A3; DAT1), DA receptor D4 (DRD4), serotonin receptor 1B (HTR1B), tryptophan hydroxylase 2 (TPH2), the norepinephrine transporter SLC6A2 and three SNPs in cadherin 13 (CDH13). Information was extracted from a recent meta-analysis of five genome-wide association studies, in which 7,689,524 SNPs in European samples were successfully imputed. No significant association was observed after correction for multiple testing. Therefore, it is reasonable to conclude that candidate variants implicated in the pathogenesis of ADHD do not play a substantial role in PD.

Neuropsychological functioning in college students with and without ADHD

OBJECTIVE

Increasing numbers of students with attention-deficit/hyperactivity disorder (ADHD) are attending college; however, little empirical information is available concerning the functional impairment experienced by these students. Although preliminary studies suggest that college students with ADHD are more likely to experience a variety of psychosocial and academic difficulties compared to their peers without the disorder, findings regarding neuropsychological functioning have been inconsistent with some studies reporting that college students with ADHD perform more poorly on various cognitive and neuropsychological tasks while others report no differences compared to their peers without ADHD.

METHOD

The purposes of the present study, the Trajectories Related to ADHD in College project, a longitudinal study following the 4-year outcomes of college students with and without ADHD, were to (a) examine the performance of 436 first-year college students with and without ADHD (51.6% female) on measures of executive function (EF) and intelligence and (b) investigate the association of self-reported use of stimulant medication and neuropsychological performance in students with ADHD. Participant data from their first year of involvement in the study were analyzed.

RESULTS

Participants with ADHD performed more poorly on task-based and self-report EF measures relative to the comparison group. In contrast, no significant group differences were found with respect to intellectual performance. Within the ADHD group, use of prescription stimulant medication was associated with improved performance on some, but not all, neuropsychological tasks. Additional analyses also revealed significant group differences in EF based on clinical diagnostic status.

CONCLUSION

College students with ADHD demonstrated poorer EF than their peers without ADHD and psychostimulant medication was associated with improved EF performance. No group differences were found with respect to intellectual functioning, Lastly, having one or more comorbid psychiatric diagnoses in addition to ADHD was associated with poorer EF outcomes. (PsycINFO Database Record

Assessment of Attention Deficits in Adolescent Offspring Exposed to Maternal Type 1 Diabetes

OBJECTIVE

The aim of this study was to examine the potential association between intrauterine exposure to maternal diabetes and attention deficits in the offspring.

RESEARCH DESIGN AND METHODS

Adolescent offspring of a prospectively followed cohort of women with type 1 diabetes (n = 269) and a control group from the background population (n = 293) participated in a follow-up assessment in 2012-2013. We used scores from Conners Continuous Performance Test II to assess attention and based on a principal component analysis we evaluated scores on five different attention factors: focused attention, vigilance, hyperactivity/impulsivity, sustained attention and response style.

RESULTS

A higher frequency of the exposed offspring had a parent/self-reported use of Attention Deficit Hyperactivity Disorder (ADHD) medication compared to the control group (2.2% vs. 0.0%, p = 0.01). Clinical significant differences between adolescents exposed to maternal diabetes and unexposed controls were not found in either single scores on Conners Continuous Performance Test or on any of the five attention factors identified.

CONCLUSIONS

Exposure to maternal type 1 diabetes did not seem to increase the risk of attention deficits in the adolescent offspring. However, a higher self-reported use of ADHD medication in the exposed group could suggest a difference in attention not revealed by the applied test.

Non-linearities in Theory-of-Mind Development

Research on Theory-of-Mind (ToM) has mainly focused on ages of core ToM development. This article follows a quantitative approach focusing on the level of ToM understanding on a measurement scale, the ToM Storybooks, in 324 typically developing children between 3 and 11 years of age. It deals with the eventual occurrence of developmental non-linearities in ToM functioning, using smoothing techniques, dynamic growth model building and additional indicators, namely moving skewness, moving growth rate changes and moving variability. The ToM sum-scores showed an overall developmental trend that leveled off toward the age of 10 years. Within this overall trend two non-linearities in the group-based change pattern were found: a plateau at the age of around 56 months and a dip at the age of 72–78 months. These temporary regressions in ToM sum-score were accompanied by a decrease in growth rate and variability, and a change in skewness of the ToM data, all suggesting a developmental shift in ToM understanding. The temporary decreases also occurred in the different ToM sub-scores and most clearly so in the core ToM component of beliefs. It was also found that girls had an earlier growth spurt than boys and that the underlying developmental path was more salient in girls than in boys. The consequences of these findings are discussed from various theoretical points of view, with an emphasis on a dynamic systems interpretation of the underlying developmental paths.

Risk factors for the existence of attention deficit hyperactivity disorder symptoms in children with autism spectrum disorders

Over the years, several authors have reported symptoms of attention deficit hyperactivity disorder (ADHD) in patients with autism spectrum disorders (ASD); however, studies on the risk factors of ADHD symptoms in children with ASD are lacking. The aim of this cross-sectional study was to identify the risk factors for the development of ADHD symptoms in children with ASD. The sample consisted of 67 children with ASD who were assessed with Conner's Parent Rating Scale-Revised (CPRS-R), and with a semi-structured detailed interview administered to parents, to collect a series of clinical data such as coexisting somatic and neuropsychiatric problems and familial and pre/peri/postpartum risk factors. We found that 55% of ASD children exceeded the cut-off of CPRS-R Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), total scale. The univariate analyses showed that children's age (P=0.048), motor delay (P=0.039), enuresis (P=0.014), allergies (P<0.01), comorbid oppositional defiant disorder (P=0.026) and intellectual disabilities comorbidities (P=0.034) were associated to the CPRS-R DSM-IV total score. Some familial predictors such as neuropsychiatric family history of intellectual disabilities (P=0.003) and psychosis (P=0.039) were related to the CPRS-R DSM-IV total score. In particular, a model including allergies (P=0.000) and family history of psychosis (P=0.03) explained 25% (corrected R²=0.25) of the variance of the DSM-IV ADHD score. In conclusion, we identified some risk factors associated with the development of ADHD symptoms in ASD children that need to be studied further.

Alterations of Growth Factors in Autism and Attention-Deficit/Hyperactivity Disorder

Growth factors (GFs) are cytokines that regulate the neural development. Recent evidence indicates that alterations in the expression level of GFs during embryogenesis are linked to the pathophysiology and clinical manifestations of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). In this concise review, we summarize the current evidence that supports the role of brain-derived neurotrophic factor, insulin-like growth factor 2, hepatocyte growth factor (HGF), glial-derived neurotrophic factor, nerve growth factor, neurotrophins 3 and 4, and epidermal growth factor in the pathogenesis of ADHD and ASD. We also highlight the potential use of these GFs as clinical markers for diagnosis and prognosis of these neurodevelopmental disorders.

Attentional Networks in Adolescents with High-functioning Autism: An fMRI Investigation

Background:

Attentional deficits in Autism spectrum disorder (ASD) are often noted, but their specific nature remains unclear.

Objective:

The present study used the child Attentional Network Task (Child ANT) in combination with functional magnetic resonance imaging (fMRI) to determine if the consistently cited deficits of orienting attention are truly due to dysfunctions of orienting-based networks. We hypothesized that these observations are, in fact, a reflection of executive dysfunctions. As such, we expected that although ASD adolescents would perform worse on the orienting portion of the Child ANT, the strongest differences in activation between them and the neurotypical (NT) control group would be in areas classically associated with executive functioning (e.g., the frontal gyri and anterior cingulate cortex).

Method:

The brain activity of six high-functioning adolescents with ASD and six NT adolescents was recorded while these individuals performed the three subcomponents of the Child ANT.

Results:

ASDs were shown to be more accurate than NTs for the alerting, less accurate for the orienting, and similar in accuracy for the executive portions of the Child ANT. fMRI data showed increased bilateral frontal gyri recruitment, areas conventionally associated with executive control, during the orienting task for the ASD group.

Conclusion:

We submit that the increased activations represent neurocorrelates of signal fixation attributable to the subset of executive control responsible for sustained maintenance signals, not the main components of orienting. Therefore, excessive fixation in ASD adolescents is likely due to dysfunctions of executive control and not the orienting subcomponent of the attention network.

Screening for attention deficit and hyperactivity disorder, autism spectrum disorder, and developmental delay in Taiwanese aboriginal preschool children

OBJECTIVES

This study aimed to estimate the percentages of attention deficit and hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in Taiwanese aboriginal preschool children. Child development level was compared between the two groups.

METHODS

Teachers completed screening questionnaires for ADHD, ASD, and development level for 36- to 72-month-old children in kindergartens in Taiwan. The questionnaire results were compared between the aboriginal and nonaboriginal children. One child psychiatrist then interviewed the aboriginal preschool children to determine if they had ADHD and/or ASD.

RESULTS

We collected 93 questionnaires from the aboriginal group and 60 from the nonaboriginal group. In the aboriginal group, 5.37% of the children were identified to have ADHD, while 1.08% were identified to have ASD. Significantly fewer aboriginal children had developmental delays for situation comprehension and personal-social development (P=0.012 and 0.002, respectively) than nonaboriginal children.

CONCLUSION

Aboriginal children in Taiwan had typical percentages of ADHD and ASD compared to those published in the literature. Aboriginal children showed relative strengths in situation comprehension and personal-social skills. Further studies are required to understand the learning styles of the aboriginal children and to develop effective screening and intervention strategies for ADHD and ASD.