Developmental dissociation, deviance, and delay: Occurrence of attention-deficit-hyperactivity disorder in individuals with and without borderline-to-mild intellectual disability

Co-occurring conditions in Down syndrome: Findings from a clinical database

Individuals with Down syndrome (DS) experience a range of medical and neurodevelopmental conditions, necessitating systematic study of their occurrence and impact on neurodevelopmental outcomes. We describe the prevalence and relationships of medical, neurodevelopmental (ND), and mental health (MH) conditions in children with DS. We created a prospective clinical database of individuals with DS, integrated into the workflow of a specialty Down Syndrome Program at a specialty pediatric referral hospital. Conditions were collected through caregiver- and clinician report at clinical visits (N = 599). We calculated frequencies of medical, ND, and MH conditions and then assessed the relationship between medical, ND, and MH conditions using frequencies and comparative statistics. The most frequent co-occurring conditions were vision (72.5%), ear/hearing (71.0%), gastrointestinal (61.3%), respiratory (45.6%), and feeding (33.6%) problems, with variation in frequency by age. ND and MH conditions were reported in one quarter, most commonly autism spectrum disorder and attention-deficit/hyperactivity disorder. Those with ND and MH conditions had greater frequency of medical conditions, with highest rates of vision, ear/hearing, and gastrointestinal issues, and CHD. Systematically collected clinical data in a large cohort of children with DS reveals high prevalence of several co-occurring medical, ND, and MH conditions. Clinical care requires an understanding of the complex relationship between medical conditions and neurodevelopment.

Cognitive-attentional mechanisms of cooperation-with implications for attention-deficit hyperactivity disorder and cognitive neuroscience

People's cooperativeness depends on many factors, such as their motives, cognition, experiences, and the situation they are in. To date, it is unclear how these factors interact and shape the decision to cooperate. We present a computational account of cooperation that not only provides insights for the design of effective incentive structures but also redefines neglected social-cognitive characteristics associated with attention-deficit hyperactivity disorder (ADHD). Leveraging game theory, we demonstrate that the source and magnitude of conflict between different motives affected the speed and frequency of cooperation. Integrating eye-tracking to measure motivation-based information processing during decision-making shows that participants' visual fixations on the gains of cooperation rather than its costs and risks predicted their cooperativeness on a trial-by-trial basis. Using Bayesian hierarchical modeling, we find that a situation's prosociality and participants' past experience each bias the decision-making process distinctively. ADHD characteristics explain individual differences in responsiveness across contexts, highlighting the clinical importance of experimentally studying reactivity in social interactions. We demonstrate how the use of eye-tracking and computational modeling can be used to experimentally investigate social-cognitive characteristics in clinical populations. We also discuss possible underlying neural mechanisms to be investigated in future studies.

Stopping inappropriate medication of children with intellectual disability, autism or both: the STOMP–STAMP initiative

Children with intellectual disability are often prescribed psychotropic medication to manage behaviours that challenge. Unfortunately, many receive medication with potentially serious long-term side-effects that has been prescribed inappropriately or for longer than is necessary. NHS England launched STOMP (stopping the over-medication of people with intellectual disability, autism or both with psychotropic medicines) in 2016 to reduce the inappropriate prescribing in adults. This was broadened to include children in 2018 by the addition of STAMP (supporting treatment and appropriate medication in paediatrics). In this article we review the rationale for STOMP–STAMP, highlight the Royal College of Psychiatrists’ position statement on STOMP–STAMP and give clinical advice for psychiatrists who treat children with intellectual disability, autism and/or attention-deficit hyperactivity disorder (ADHD). Importantly, it is essential to consider that ADHD may have been missed and that by diagnosing and treating it, the need for inappropriate antipsychotic medication may be reduced.

Diagnostic progression to bipolar disorder in 17,285 adolescents and young adults with attention deficit hyperactivity disorder: A longitudinal follow-up study

OBJECTIVE

We investigated the diagnostic progression to bipolar disorder (BD) among adolescents and young adults with attention-deficit/hyperactivity disorder (ADHD).

METHODS

Using the Taiwan National Health Insurance Research Database, we enrolled adolescents and young adults aged 10-29 years with ADHD between January 1, 2001, and December 31, 2010, who were followed up until December 31, 2011, to determine progression to BD. Cox regression analysis was used to examine candidate risk and protective factors.

RESULTS

At the 11-year follow-up, the progression rate from ADHD to BD was 5.12%. Of the participants who progressed, 62.16% (322/518) progressed within the first 3 years. Risk factors for progression were as follows: older age (hazard ratio [HR], 1.058; 95% confidence interval [CI], 1.033-1.084), comorbidity with autistic spectrum disorder (HR, 1.839; 95% CI, 1.415-2.391), disruptive behavior disorder (HR, 1.434; 95% CI, 1.132-1.816), intelligence disability (HR, 1.744; 95% CI, 1.399-2.176), depressive disorder (HR, 1.978; 95% CI, 1.577-2.482), alcohol use disorder (HR, 1.705; 95% CI, 1.057-2.751), cluster A (HR, 2.508; 95% CI, 1.167-5.391) or B (HR, 2.718; 95% CI, 1.974-3.741) personality disorder, and a family history of BD (HR, 2.618; 95% CI, 1.823-3.758) Identified protective factors were male sex (HR, 0.771; 95% CI, 0.630-0.943) and cluster C personality disorder (HR, 0.278; 95% CI, 0.086-0.898).

CONCLUSION

The study demonstrated the specific risk and protective factors for BD progression among adolescents and young adults with ADHD. It is important for clinician and mental health care providers to recognize identified factors to focus on early detection and prompt intervention.

Society for Developmental and Behavioral Pediatrics Clinical Practice Guideline for the Assessment and Treatment of Children and Adolescents with Complex Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is the most common childhood neurodevelopmental disorder and is associated with an array of coexisting conditions that complicate diagnostic assessment and treatment. ADHD and its coexisting conditions may impact function across multiple settings (home, school, peers, community), placing the affected child or adolescent at risk for adverse health and psychosocial outcomes in adulthood. Current practice guidelines focus on the treatment of ADHD in the primary care setting. The Society for Developmental and Behavioral Pediatrics has developed this practice guideline to facilitate integrated, interprofessional assessment and treatment of children and adolescents with "complex ADHD" defined by age (<4 years or presentation at age >12 years), presence of coexisting conditions, moderate to severe functional impairment, diagnostic uncertainty, or inadequate response to treatment.

An Open-Label Trial of Methylphenidate Treating Sluggish Cognitive Tempo, Inattention, and Hyperactivity/Impulsivity Symptoms Among 6- to 12-Year-Old ADHD Children: What Are the Predictors of Treatment Response at Home and School?

Objective: This study investigated the effects of sluggish cognitive tempo (SCT), other psychiatric symptoms, age, dose, and pretreatment ADHD severity on methylphenidate (MPH) treatment response among ADHD children in both home and school. In addition, the predictors of the MPH-SCT treatment response were examined. Methods: One hundred eighty-five (6-12 years old) ADHD children who were treated with MPH included in the study. Results: MPH improved SCT total and SCT-Daydreaming scores both at home and school while improved SCT-Sluggish scores in only school. Higher pretreatment Daydreaming score predicted lower treatment response for inattention (B = .301, p = .002), and higher Daydreaming-Sluggish scores predicted lower treatment response for total ADHD symptoms at school (B = .456, p = .006; B = .888, p = .04, respectively). Also higher oppositional defiant disorder symptoms have negative effects on MPH treatment response in ADHD. Older age positively affected the MPH-SCT treatment response in paternal and teacher ratings. Conclusion: SCT symptoms have negative effects on MPH treatment response at school.

Patterns of comorbidity and psychopharmacology in adults with intellectual disability and attention deficit hyperactivity disorder: an UK national cross-sectional audit

Background: Attention-deficit hyperactivity disorder (ADHD) is higher in people with intellectual disability (ID) compared to the general population. Available limited evidence suggests this population has increased psychological problems, diagnostic overshadowing and psychotropic prescribing. This audit Identifies and analyzes real-world characteristics, diagnostic practices, treatment, and management of ADHD in adults with ID.Research Design and Methods: Pooled retrospective case note data for people with ID and ADHD, collected from 30 organizations across the UK, were analyzed. Patients were classified into mild and moderate-profound ID groups. Associated mental health and neurodevelopmental co-morbidity, Demographics, concomitant psychotropics, and mental and behavioral concerns were collected. Group differences were reported using logistic regression models.Results: Of 445 participants, 73% had co-occurring autism spectrum disorder (ASD) and 65% were prescribed ADHD medications. Those on ADHD medication were less likely to be prescribed antipsychotics (p < 0.001) and antidepressants (p < 0.001). Multiple significant differences were found in ADHD medication response between ID groups and those with/without co-morbid ASD but not associated with challenging behavior reduction.Conclusions: High levels of neurodevelopmental and psychiatric comorbidity were found. ID severity and the presence of ASD appear to influence the use of certain psychotropic medications. Appropriate use of ADHD medication appears to reduce psychotropic polypharmacy.

Inattention and Hyperactivity in Children with Symptomatic and Asymptomatic Congenital Cytomegalovirus

OBJECTIVES

To explore the relationship between congenital cytomegalovirus (CMV) and inattention and hyperactivity among school-aged children.

METHODS

The Behavior Assessment System for Children, Second Edition, parent- and self-report, was completed among children with symptomatic congenital CMV (ScCMV) (n = 36), asymptomatic congenital CMV (AcCMV) (n = 76), and controls (n = 29) enrolled in a longitudinal cohort. The proportions of children with ScCMV, AcCMV, and controls with Attention Problems or Hyperactivity T-scores ever ≥ 65 were compared. Mean T-scores in these domains were also compared and adjusted for IQ.

RESULTS

Children with AcCMV did not differ from controls in the proportion of children with elevated Attention Problems or Hyperactivity T-scores or in mean Attention Problems or Hyperactivity T-scores. Children with ScCMV had a higher proportion of elevated Attention Problems T-scores compared with the AcCMV group but not controls. There were no differences in the proportions of children with elevated Hyperactivity T-scores between ScCMV and AcCMV or control groups. Children with ScCMV had higher mean Attention Problems T-scores versus those with AcCMV and controls and higher mean Hyperactivity T-scores versus those with AcCMV but not controls. After adjustment for IQ, differences in mean Attention Problems or Hyperactivity T-scores were no longer significant.

CONCLUSION

Children with AcCMV are not at increased risk of inattention or hyperactivity compared with controls. However, our study suggests an increased prevalence of inattention and hyperactivity among children with ScCMV. Differences in IQ were confirmed to have a confounding effect. Evaluation for attention-deficit/hyperactivity disorder may be warranted in this population.

Within-task variability on standardized language tests predicts autism spectrum disorder: a pilot study of the Response Dispersion Index

Background

Qualitatively atypical language development characterized by non-sequential skill acquisition within a developmental domain, which has been called developmental deviance or difference, is a common characteristic of autism spectrum disorder (ASD). We developed the Response Dispersion Index (RDI), a measure of this phenomenon based on intra-subtest scatter of item responses on standardized psychometric assessments, to assess the within-task variability among individuals with language impairment (LI) and/or ASD.

Methods

Standard clinical assessments of language were administered to 502 individuals from the New Jersey Language and Autism Genetics Study (NJLAGS) cohort. Participants were divided into four diagnostic groups: unaffected, ASD-only, LI-only, and ASD + LI. For each language measure, RDI was defined as the product of the total number of test items and the sum of the weight (based on item difficulty) of test items missed. Group differences in RDI were assessed, and the relationship between RDI and ASD diagnosis among individuals with LI was investigated for each language assessment.

Results

Although standard scores were unable to distinguish the LI-only and ASD/ASD + LI groups, the ASD/ASD + LI groups had higher RDI scores compared to LI-only group across all measures of expressive, pragmatic, and metalinguistic language. RDI was positively correlated with quantitative ASD traits across all subgroups and was an effective predictor of ASD diagnosis among individuals with LI.

Conclusions

The RDI is an effective quantitative metric of developmental deviance/difference that correlates with ASD traits, supporting previous associations between ASD and non-sequential skill acquisition. The RDI can be adapted to other clinical measures to investigate the degree of difference that is not captured by standard performance summary scores.

Electronic supplementary material

The online version of this article (10.1186/s11689-019-9283-z) contains supplementary material, which is available to authorized users.

Psychiatric comorbidities of mild intellectual disability in children and adolescents in a clinical setting

The aim of this study was to investigate the psychiatric disorders that accompany mild intellectual disability (ID) in school-aged children in a clinical setting. The Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version interview was conducted with the children with mild ID and their parents to diagnose any comorbid disorders. The mean age of the 111 children that fulfilled the study criteria was 12.09 ± 3.28 years, 59 of them (53.2%) were males, and 80.2% had at least one lifetime comorbid psychiatric diagnosis. Attention deficit hyperactivity disorder (64.9%), oppositional defiant disorder (21.6%), anxiety disorders (18.0%), were the most common comorbidities. The correlates of exhibiting comorbid psychiatric disorder were being male and irritability symptoms in the clinical history. Being aware of the comorbid psychiatric disorders and planning treatment strategies toward all of the diagnoses may help in the adaptation and rehabilitation of children with mild IDs.

Attention Deficit Hyperactivity Disorder in people with Intellectual Disability

Two case reports of people with severe intellectual disability (ID), Autism and challenging behaviour are discussed here to describe the presentation of attention-deficit hyperactivity disorder (ADHD) in people with ID. Both cases highlight how the diagnosis of ADHD can be missed and the behaviours attributed to ID and autism, which could lead to using ineffective treatment strategies. The case reports illustrate the importance of the diagnosis and treatment of ADHD in people with ID and how it can make a difference to their clinical presentation and quality of life.

Gestational age at birth and risk of intellectual disability without a common genetic cause

Preterm birth is linked to intellectual disability and there is evidence to suggest post-term birth may also incur risk. However, these associations have not yet been investigated in the absence of common genetic causes of intellectual disability, where risk associated with late delivery may be preventable. We therefore aimed to examine risk of intellectual disability without a common genetic cause across the entire range of gestation, using a matched-sibling design to account for unmeasured confounding by shared familial factors. We conducted a population-based retrospective study using data from the Stockholm Youth Cohort (n = 499,621) and examined associations in a nested cohort of matched outcome-discordant siblings (n = 8034). Risk of intellectual disability was greatest among those born extremely early (adjusted OR_{24 weeks} = 14.54 [95% CI 11.46-18.44]), lessening with advancing gestational age toward term (aOR_{32 weeks} = 3.59 [3.22-4.01]; aOR_37weeks = 1.50 [1.38-1.63]); aOR_{38 weeks} = 1.26 [1.16-1.37]; aOR₃₉ weeks = 1.10 [1.04-1.17]) and increasing with advancing gestational age post-term (aOR_{42 weeks} = 1.16 [1.08-1.25]; aOR_{43 weeks} = 1.41 [1.21-1.64]; aOR_{44 weeks} = 1.71 [1.34-2.18]; aOR_{45 weeks} = 2.07 [1.47-2.92]). Associations persisted in a cohort of matched siblings suggesting they were robust against confounding by shared familial traits. Risk of intellectual disability was greatest among children showing evidence of fetal growth restriction, especially when birth occurred before or after term. Birth at non-optimal gestational duration may be linked causally with greater risk of intellectual disability. The mechanisms underlying these associations need to be elucidated as they are relevant to clinical practice concerning elective delivery around term and mitigation of risk in post-term children.

Inattention and hyperactivity/impulsivity among children with attention-deficit/hyperactivity-disorder, autism spectrum disorder, and intellectual disability

BACKGROUND

Attention-Deficit/Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), and Intellectual Disability (ID) are common co-occurring neurodevelopmental disorders; however, limited research exists regarding the presentation and severity of overlapping symptomology, particularly inattention and hyperactivity/impulsivity, when a child is diagnosed with one of more of these neurodevelopmental disorders.

AIMS

As difficulties with inattention and hyperactivity/impulsivity are symptoms frequently associated with these disorders, the current study aims to determine the differences in the severity of inattention and hyperactivity/impulsivity in children diagnosed with ADHD, ASD, ID, and co-occurring diagnosis of ADHD/ID, ASD/ADHD, and ASD/ID.

METHODS AND PROCEDURES

Participants in the current study included 113 children between the ages of 6 and 11 who were diagnosed with ADHD, ASD, ID, ADHD/ID, ASD/ADHD, or ASD/ID. Two MANOVA analyses were used to compare these groups witih respsect to symptom (i.e., inattention, hyperactivity/impulsivity) severity.

OUTCOMES AND RESULTS

Results indicated that the majority of diagnostic groups experienced elevated levels of both inattention and hyperactivity/impulsivity. However, results yielded differences in inattention and hyperactivity/impulsivity severity. In addition, differences in measure sensitivity across behavioral instruments was found.

CONCLUSIONS AND IMPLICATIONS

Children with neurodevelopmental disorders often exhibit inattention and hyperactivity/impulsivity, particularly those with ADHD, ASD, ASD/ADHD, and ADHD/ID; therefore, differential diagnosis may be complicated due to similarities in ADHD symptom severity. However, intellectual abilities may be an important consideration for practitioners in the differential diagnosis process as children with ID and ASD/ID exhibited significantly less inattention and hyperactive/impulsive behaviors. Additionally, the use of multiple behavior rating measures in conjunction with other assessment procedures may help practitioners determine the most appropriate diagnosis.

Imaging genetics in neurodevelopmental psychopathology

Neurodevelopmental disorders are defined by highly heritable problems during development and brain growth. Attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASDs), and intellectual disability (ID) are frequent neurodevelopmental disorders, with common comorbidity among them. Imaging genetics studies on the role of disease-linked genetic variants on brain structure and function have been performed to unravel the etiology of these disorders. Here, we reviewed imaging genetics literature on these disorders attempting to understand the mechanisms of individual disorders and their clinical overlap. For ADHD and ASD, we selected replicated candidate genes implicated through common genetic variants. For ID, which is mainly caused by rare variants, we included genes for relatively frequent forms of ID occurring comorbid with ADHD or ASD. We reviewed case-control studies and studies of risk variants in healthy individuals. Imaging genetics studies for ADHD were retrieved for SLC6A3/DAT1, DRD2, DRD4, NOS1, and SLC6A4/5HTT. For ASD, studies on CNTNAP2, MET, OXTR, and SLC6A4/5HTT were found. For ID, we reviewed the genes FMR1, TSC1 and TSC2, NF1, and MECP2. Alterations in brain volume, activity, and connectivity were observed. Several findings were consistent across studies, implicating, for example, SLC6A4/5HTT in brain activation and functional connectivity related to emotion regulation. However, many studies had small sample sizes, and hypothesis-based, brain region-specific studies were common. Results from available studies confirm that imaging genetics can provide insight into the link between genes, disease-related behavior, and the brain. However, the field is still in its early stages, and conclusions about shared mechanisms cannot yet be drawn.

What can large population-based birth cohort study ask about past, present and future of children with disorders of development, learning and behaviour?

A large cohort consisting of all children born to mothers from community provides 'natural' selection into different exposures and is a powerful resource for epidemiological research. A large population-based birth cohort with detailed systematic information already recorded, as part of longitudinal medical care, historical and current school data, detailed birth certificate data and all three resources available for every member of the birth cohort, are extremely rare. Our population-based birth cohort consists of all children born between 1976 and 2000 to mothers residing in Olmsted County, Minnesota, at the time of child's birth (N=39 890). In this paper, we provide a comprehensive report of the method describing the identification, the characteristics and longitudinal follow-up of each child (and family members) from the birth cohort, wealth of complementary resources of data and study measures and designs (retrospective, combined retrospective/prospective). In the last decade or so, we obtained scientific and clinically needed answers for incidence rates, potential risk/protective factors, treatment, comorbidities, outcomes, cost/usage and potential biases (that are always assessed and clinically interpreted) of many developmental learning and behavioural disorders (DLBDs) including learning and attention-deficit/hyperactivity disorders, intellectual disability, speech-language impairment and autism spectrum disorder. Many current and future questions related to DLBDs are remaining to be answered. The Olmsted County Birth Cohort (OCBC) is an example of a comprehensive, contemporary epidemiological research model for the development of similar research infrastructures, and its current and future results are important for replication and comparison with other population-based retrospective and prospective birth cohort studies.

Social Competence in Children with Borderline Intellectual Functioning: Delayed Development of Theory of Mind Across All Complexity Levels

Borderline intellectual functioning (BIF) is characterized by heterogeneous cognitive difficulties, with an intelligence quotient (IQ) between 70 and 85 points, and a failure to meet the developmental and sociocultural standards for personal independence and social responsibility required in daily life. The fact that this population still remain a marginal clinical category, with no ad hoc diagnostic and therapeutic approaches, has stimulated the present research. Our goal was to study children with BIF investigating the development of Theory of Mind (ToM) as a pillar of social competence. Children with BIF (N = 28, 16 male/12 female, and mean age 9.46 ± 1.26 years) and children with typical development (TD; N = 31, 17 male/14 female; mean age 8.94 years ± 0.99) underwent a neurocognitive assessment and a ToM assessment. Children with BIF showed a significant lower performance across all the levels of ToM development investigated compared to the control group, and a correlation between executive functions and the advanced levels of ToM reasoning. These results constitute a first step in the direction of defining the clinical profile of children with BIF concerning ToM development, opening the way to future interventions in order to support the developmental evolution of this population in an adaptive direction.

Association of hair manganese level with symptoms in attention-deficit/hyperactivity disorder

OBJECTIVE

The study examined the association between hair manganese level and symptoms of attention-deficit/hyperactivity disorder (ADHD) in Korean children.

METHODS

Forty clinic-referred children with ADHD and 43 normal control children participated in this study. The participants were 6-15 years old and were mainly from the urban area of Seoul, Korea. ADHD was diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition and Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version-Korean Version. The severity and symptoms of ADHD was evaluated according to the ADHD Diagnostic System, and parent's Korean ADHD Rating Scale (K-ARS). All participants completed intelligence test and hair mineral analysis. We divided the data of hair Mn into two groups to determine whether a deficit or excess of Mn are associated with ADHD. Multiple logistic regression analyses were performed to identify hair manganese levels associated with ADHD, controlling for age, sex, and full scale intelligence quotient (IQ).

RESULTS

The proportion of abnormal range Mn group was significantly high in ADHD compared to controls. However, after statistical control for covariates including age and sex, abnormal range Mn group was significantly associated with ADHD (OR=6.40, 95% CI=1.39-29.41, p=0.017).

CONCLUSION

The result of this study suggests that excess exposure or deficiency of Mn were associated with ADHD among children in Korea. Further investigation is needed to evaluate the effects of hair manganese levels on symptoms in ADHD.

Factor structure of autistic traits in children with ADHD

Attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) often co-occur. Factor analyses of ASD traits in children with and without ASD indicate the presence of social and restrictive–repetitive behaviour (RRB) factors. This study used exploratory factor analyses to determine the structure of ASD traits (assessed using the Social Communication Questionnaire) in children with ADHD. Distinct factors were observed for ‘social’ and ‘rigidity’ traits, corresponding to previous factor analyses in clinical ASD and population samples. This indicates that the split between social-communicative and RRB dimensions is unaffected by ADHD in children. Moreover, the study also finds that there is some overlap across hyperactive-impulsive symptoms and RRB traits in children with ADHD, which merits further investigation.

Autistic traits in children with ADHD index clinical and cognitive problems

Traits of autistic spectrum disorders (ASD) occur frequently in attention deficit hyperactivity disorder (ADHD), but the significance of their presence in terms of phenotype and underlying neurobiology is not properly understood. This analysis aimed to determine whether higher levels of autistic traits, as measured by the Social Communication Questionnaire (SCQ), index a more severe presentation in a large, rigorously phenotyped sample of children with ADHD (N=711). Regression analyses were used to examine association of SCQ scores with core ADHD features, clinical comorbidities and cognitive and developmental features, with adjustment for putative confounders. For outcomes showing association with total SCQ score, secondary analyses determined levels of differential association of the three ASD sub-domains. Results suggest that increasing ASD symptomatology within ADHD is associated with a more severe phenotype in terms of oppositional, conduct and anxiety symptoms, lower full-scale IQ, working memory deficits and general motor problems. These associations persisted after accounting for ADHD severity, suggesting that autistic symptomatology independently indexes the severity of comorbid impairments in the context of ADHD. Sub-domain scores did not show unique contributions to most outcomes, except that social deficits were independently associated with oppositional symptoms and repetitive behaviours independently predicted hyperactive-impulsive symptoms and motor problems. It would be worthwhile for clinicians to consider levels of socio-communicative and repetitive traits in those with ADHD who do not meet diagnostic criteria for ASD, as they index higher levels of phenotypic complexity, which may have implications for efficacy of interventions.

Intellectual disability in children with attention deficit hyperactivity disorder

OBJECTIVE

To determine whether children with attention deficit hyperactivity disorder (ADHD) and mild intellectual disability (ID) are a clinically distinct ADHD subgroup.

STUDY DESIGN

This was a cross-sectional study comparing clinical characteristics (ADHD subtypes, total number of symptoms, and rates of common comorbidities) between children with ADHD and mild ID and those with ADHD and IQ test scores >70, and also between children with ADHD and ID and a general population sample of children with ID alone. The sample comprised a clinical sample of children with ADHD with ID (n = 97) and without ID (n = 874) and a general population sample of children with ID and without ADHD (n = 58).

RESULTS

After correcting for multiple statistical tests, no differences were found between the 2 ADHD groups on any measure except the presence of conduct disorder (CD) symptoms and diagnoses. Children with ADHD and ID had higher rates of both (OR, 2.38; 95% CI, 1.71-3.32 and OR, 2.69; 95% CI, 1.69-4.28, respectively). Furthermore, children with ADHD and ID had significantly higher rates of oppositional defiant disorder (OR, 5.54; 95% CI, 2.86-10.75) and CD (OR, 13.66; 95% CI, 3.25-57.42) symptoms and a higher incidence of oppositional defiant disorder diagnoses (OR, 30.99; 95% CI, 6.38-150.39) compared with children with ID without ADHD.

CONCLUSION

Children with ADHD and mild ID appear to be clinically typical of children with ADHD except for more conduct problems. This finding has implications for clinicians treating these children in terms of acknowledging the presence and impact of ADHD symptoms above and beyond ID and dealing with a comorbid CD.

Developmental and behavioral disorders through the life span

Developmental and behavioral disorders including intellectual disability, learning disabilities, and attention-deficit/hyperactivity disorder are highly prevalent, chronic health conditions. Despite being versed in caring for children with these conditions, pediatricians might be less prepared for challenging questions from families about the long-term course of these conditions and what can be done to improve outcomes. Through this state-of-the-art review, we provide clinicians with an understanding of the course of these conditions and adult outcomes in several areas including vocational, social, and health domains. We also provide a review of the most current research examining factors that predict or mediate adult outcomes for people with intellectual disability, learning disabilities, and attention-deficit/hyperactivity disorder. On the basis of the current literature, we offer practice recommendations aimed at optimizing adult outcomes for those with these disorders.

Attention-deficit/hyperactivity disorder among children with and without intellectual disability: an examination across time

BACKGROUND

Children with intellectual and developmental disabilities are at heightened risk for mental disorders, and disruptive behaviour disorders appear to be the most prevalent. The current study is a longitudinal examination of attention-deficit/hyperactivity disorder (ADHD) among children with and without intellectual disability (ID) across ages 5 to 8.

METHOD

We assessed 228 5-year-old children, 87 with ID and 141 with typical development (TD), for clinical diagnoses using a structured interview. These interviews were conducted with mothers annually from child age 5 to 8.

RESULTS

Attention-deficit/hyperactivity disorder was over 3 times as prevalent in the ID group as in the TD group across ages 5, 6, 7 and 8. The diagnosis of ADHD tended to emerge earlier and was more stable in the ID group; however, the total number and relative frequency of ADHD symptoms endorsed appeared to be similar within the two groups across time. With respect to the developmental course, the trajectories of ADHD inattentive and hyperactive/impulsive symptoms over time were similar in the two groups.

DISCUSSION

Children with ID appear to be at heightened risk for ADHD and they may experience a longer and more persistent course of the disorder. These findings highlight the need for making interventions available for early treatment of this condition in children with ID.

Prevalence of chronic health conditions in children with intellectual disability: a systematic literature review

A systematic review of the prevalence rates of chronic health conditions in populations of children with intellectual disability was provided. We identified 2,994 relevant studies by searching Medline, Cinahl, and PsycINFO databases from 1996 to 2008. We included the 31 studies that had sufficient methodological quality. The 6 most prevalent chronic health conditions in children with intellectual disability were epilepsy (22.0/100), cerebral palsy (19.8/100), any anxiety disorder (17.1/100), oppositional defiant disorder (12.4/100), Down syndrome (11.0/100), and autistic disorder (10.1/100). The reported prevalence rates of chronic health conditions in this population was much higher than in the general population. However, both the number of studies that were included and the number of chronic health conditions they reported about were limited. There is an urgent need for better evidence on the prevalence of chronic health conditions among children with intellectual disability.

Determinants of activity and participation in preschoolers with developmental delay

According to the International Classification of Functioning, Disability and Health model endorsed by the World Health Organization, activity (the execution of a task or action by an individual), and participation (involvement in a life situation) are important components in the assessment of health and functioning of an individual. The purpose of this study was to compare the activity performance and school participation of preschool children with developmental delay (DD) and age-matched typically developing children, and to identify the determinants of activity and participation in preschoolers with DD. Fifty-four children with DD (37 boys, 17 girls; mean age: 66 months) and 54 age-matched typically developing children (34 boys, 20 girls; mean age: 65 months) were recruited from the mainstream preschools with integrated program units. Activity and participation were evaluated using the Vineland Adaptive Behavior Scales (VABS) and School Function Assessment (SFA). Other factors that may influence activity and participation such as impairments in sensory, motor, and mental functioning, and other contextual factors (e.g. family income) were also measured. The DD group had significantly lower VABS (p < 0.001) and SFA (p<0.001) scores than controls, indicating suboptimal activity and participation. Multiple regression analysis revealed that deficits in social and motor skills, and in inattention/hyperactivity, were significantly associated with activity and participation in children with DD, accounting for approximately 35-37% of the variance in the VABS and SFA scores ( p<0.001). In conclusion, deficits in social and motor functioning, and attention-deficit hyperactivity disorder-related symptoms, are important determinants of activity and participation in preschoolers with DD. One may consider targeting these specific areas to enhance activity and participation amongst these children.

Attention-deficit hyperactivity disorder in children with high intelligence quotient: results from a population-based study

OBJECTIVE

To compare the characteristics of children with attention-deficit hyperactivity disorder (ADHD) who have high intelligence quotient (IQ) versus normal and low IQ through long-term follow-up of children with ADHD from a population-based birth cohort.

METHODS

Subjects included children with research-identified ADHD (N = 379) from a birth cohort (N = 5718). Full scale IQ scores obtained between ages 6 and 18 years were used to categorize children into 3 groups: Low (IQ < 80), Normal (80 ≤ IQ < 120), and High IQ (IQ ≥ 120). Subjects were retrospectively followed up from birth until emigration, death, or high school graduation/dropout. The groups were compared on demographic characteristics, age at which ADHD case criteria were met, comorbidities, treatment, and school outcomes.

RESULTS

There were no significant differences among children with high (N = 34), normal (N = 276), or low IQ (N = 21) and ADHD in numerous characteristics, including median age at which ADHD criteria were fulfilled (9.5, 9.7, and 9.8 years); rates of comorbid learning disorders (85.3%, 78.3%, and 76.2%), psychiatric disorders (47.1%, 50.4%, and 47.6%), and substance abuse (17.6%, 23.6%, and 19.0%); and rates of stimulant treatment (79%, 75%, and 90%). In comparison to children with normal or low IQ, those with high IQ had mothers with higher educational levels (e.g., college graduation rates 44.1%, 11.6%, and 14.3%), and higher reading achievement (median national percentiles on standardized reading tests 77.0, 42.0, and 29.0, p < 0.001).

CONCLUSIONS

These findings suggest that ADHD is similar among children with high, normal, and low IQ, although high IQ may favorably mediate some outcomes such as reading achievement. Diagnosis and treatment of ADHD are important for all children, regardless of cognitive ability.

Limited concordance between teachers, parents and healthcare professionals on the presence of chronic diseases in ID-adolescents

Evidence on teachers' knowledge about somatic and mental chronic diseases among ID-adolescent compared to the knowledge parents and healthcare professionals have, is limited. The aim of this study is: (1) to assess the knowledge of teachers on the presence of chronic diseases in ID-adolescents; (2) to compare teachers with parents and healthcare professionals and parents with healthcare professionals regarding the knowledge on the presence of chronic diseases in ID-adolescents. We obtained data on 1044 ID-adolescents attending secondary schools, fully covering one region of the Netherlands. Teachers, parents and general practitioners (GPs) of the adolescents completed a questionnaire about the occurrence of chronic diseases in their child during the previous 12 months. The questionnaire was derived from the Dutch National Permanent Survey on Living Conditions questionnaire periodically administered in a representative population sample (n ≈ 10,000). Concordance between teachers, parents and healthcare professionals on the presence of chronic diseases in ID-adolescents was relatively low. In about half of all 66 dyads the concordance was for the most part fair and just in 10 dyads good to very good; nine of these latter cases concerned somatic chronic diseases. In addition, teachers reported mostly lower prevalence rates of chronic diseases in ID-adolescents compared to the parents, in particular on mental chronic diseases. Although prevalence rates of chronic diseases among ID-adolescents are very high, knowledge on this among teachers is limited. While information on chronic diseases in ID-adolescents is available among different informants, the disagreement between them reflects different points of view between the informants and probably indicates a lack of communication. The communication among teachers, parents and GPs should be improved to combine the knowledge and information on the presence of chronic diseases in ID-adolescents. This may provide opportunities to improve the support of these adolescents in their school career and in their transition from school to work.

Mental disorders in five-year-old children with or without developmental delay: focus on ADHD

Epidemiological studies of children and adolescents with intellectual disability have found 30 to 50% exhibiting clinically significant behavior problems. Few studies, however, have assessed young children, included a cognitively typical comparison group, assessed for specific disorders, and/or studied family correlates of diagnosis. We assessed 236 5-year-old children--95 with developmental delay (DD) and 141 with typical development--for clinical diagnoses using a structured interview. Every disorder assessed was more prevalent in the DD group. The percent of children meeting criteria for Attention Deficit Hyperactivity Disorder (ADHD) most highly differentiated the two groups (ratio = 3.21:1). There was high stability from externalizing behavior problems at age 3 to ADHD diagnoses at age 5 in both groups. In regression analyses, parenting stress at child age 3 related to later ADHD diagnosis in both groups and maternal scaffolding (sensitive teaching) also predicted ADHD in the DD group.

Dificuldades no diagnóstico de TDAH em crianças

O transtorno do déficit de atenção e/ou hiperatividade (TDAH) é uma doença de alta prevalência em crianças em idade escolar. Erroneamente entendido anteriormente como um diagnóstico de baixa morbidade, o TDAH é reconhecido atualmente como uma condição importante, não só pelo forte impacto funcional e social como também pela alta prevalência de comorbidades psiquiátricas. Déficits cognitivos globais e transtornos invasivos do desenvolvimento assim como transtornos do aprendizado são condições complexas que, quando estão associadas aos sintomas de TDAH, têm seus quadros agravados, requerendo maior atenção e estratégias de tratamento mais individualizadas. O objetivo deste artigo é uma discussão sobre esses diagnósticos diferenciais que representam um desafio na prática clínica.