Autism symptoms in Attention-Deficit/Hyperactivity Disorder: a familial trait which correlates with conduct, oppositional defiant, language and motor disorders

A comparison of visual attention to pictures in the Autism Diagnostic Observation Schedule in children and adolescents with ADHD and/or autism

Background

Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) are neurodevelopmental conditions which frequently co-occur. The Autism Diagnostic Observation Schedule (ADOS) is commonly used to aid with diagnostic assessment of ASD but was not originally designed for use in those with comorbid ADHD. Visual attention to social stimuli has been often studied in ASD using eye-tracking, to obtain quantitative indices of how attention is deployed to different parts of a social image/scene. As the ADOS includes tasks that rely on attending to and processing images of social scenes, these measures of visual attention could provide useful additional objective measurement alongside ADOS scores to enhance the characterisation of autistic symptoms in those with ADHD.

Methods

Children with ASD, comorbid ASD and ADHD, ADHD and Neurotypical (NT) controls were recruited (n=84). Visual attention was measured using eye-tracking during free viewing of social scenes selected from the ADOS. The full ADOS was then administered. Stimulant medication was temporarily withdrawn during this assessment. Research diagnoses were based on the Development and Wellbeing Assessment (DAWBA), ADOS, Social Communication Questionnaire (SCQ, a measure of ASD severity) and Conners' Rating Scales (CRS-3, a measure of ADHD severity) following clinical consensus.

Results

Using factorial ANOVAs to model ADHD, Autism and their interaction, we found that fixation duration to faces was reduced in those with ASD (ASD and ASD+ADHD) compared to those without ASD (ADHD and NT). Reduced visual attention to faces in the whole sample was associated with Autism symptom severity (SCQ subscale scores) but not ADHD symptom severity (CRS-3 scores).

Discussion

Our findings provide preliminary evidence in support of implementing visual attention measurement during assessment of ASD in the context of comorbidity with ADHD. For example, if a child with ADHD was found to reduce attention to faces in ADOS pictures this may suggest additive difficulties on the autism spectrum. Replication across a larger sample would be informative. This work has future potential in the clinic to help with complex cases, including those with co-occurring ADHD and ASD.

The effectiveness of weighted blankets on sleep and everyday activities - A retrospective follow-up study of children and adults with attention deficit hyperactivity disorder and/or autism spectrum disorder

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) and Autism Spectrum Disorder (ASD) are often accompanied by sleep problems influencing social, emotional and cognitive functioning in everyday activities.

AIM

The aim of this study was to investigate whether the use of a weighted blanket has a positive impact on sleep and everyday activities in individuals with ADHD and/or ASD.

MATERIAL AND METHODS

The study included 85 individuals diagnosed with ADHD and/or ASD, 48 children aged ≤17 (57%) and 37 adults ≥18 years (44%), who were prescribed with a weighted blanket. The participants responded via a telephone interview.

RESULTS

Findings demonstrated that a weighted blanket improved abilities related to falling asleep, sleeping the whole night, and relaxing during the day. Using a weighted blanket improved morning/evening daily routine, including preparing/going to sleep and waking up in the morning.

CONCLUSIONS

Weighted blankets showed positive impact on falling asleep, sleeping the whole night, and relaxing during the day, and they were used frequently by children and adults with ADHD and/or ASD. Findings indicate that a weighted blanket improved morning/evening routine, however this research area needs further investigation using both subjective and objective parameters.

Probing the overarching continuum theory: data-driven phenotypic clustering of children with ASD or ADHD

The clinical validity of the distinction between ADHD and ASD is a longstanding discussion. Recent advances in the realm of data-driven analytic techniques now enable us to formally investigate theories aiming to explain the frequent co-occurrence of these neurodevelopmental conditions. In this study, we probe different theoretical positions by means of a pre-registered integrative approach of novel classification, subgrouping, and taxometric techniques in a representative sample (N = 434), and replicate the results in an independent sample (N = 219) of children (ADHD, ASD, and typically developing) aged 7-14 years. First, Random Forest Classification could predict diagnostic groups based on questionnaire data with limited accuracy-suggesting some remaining overlap in behavioral symptoms between them. Second, community detection identified four distinct groups, but none of them showed a symptom profile clearly related to either ADHD or ASD in neither the original sample nor the replication sample. Third, taxometric analyses showed evidence for a categorical distinction between ASD and typically developing children, a dimensional characterization of the difference between ADHD and typically developing children, and mixed results for the distinction between the diagnostic groups. We present a novel framework of cutting-edge statistical techniques which represent recent advances in both the models and the data used for research in psychiatric nosology. Our results suggest that ASD and ADHD cannot be unambiguously characterized as either two separate clinical entities or opposite ends of a spectrum, and highlight the need to study ADHD and ASD traits in tandem.

Mitochondrial DNA copy number in autism spectrum disorder and attention deficit hyperactivity disorder: a systematic review and meta-analysis

Background

Several reports suggest that altered mitochondrial DNA copy number (mtDNA-cn), a common biomarker for aberrant mitochondrial function, is implicated in autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), but the results are still elusive.

Methods

A meta-analysis was performed to summarize the current indication and to provide a more precise assessment of the mtDNA-cn in ASD and ADHD. A search in the MEDLINE-PubMed, Scopus, and EMBASE databases was done to identify related studies up to the end of February 2023. The meta-analysis was conducted according to recommendations of the Cochrane Handbook of Systematic Reviews.

Results

Fourteen studies involving 666 cases with ASD and ADHD and 585 controls were collected and judged relevant for the systematic review and meta-analysis. The pooled results by a random effects meta-analysis was reported as a geometric mean of the estimated average response ratio and 95% confidence interval. Overall analysis of studies reported differences in mtDNA-cn in blood samples (k = 10) and non-blood samples (brain tissues and oral samples; k = 4) suggested significantly higher mtDNA-cn in patients compared to controls (p = 0.0275). Sub-analysis by stratifying studies based on tissue type, showed no significant increase in mtDNA-cn in blood samples among patients and controls (p = 0.284). Conversely, higher mtDNA-cn was observed in non-blood samples in patients than in controls (p = 0.0122). Further stratified analysis based on blood-cell compositions as potential confounds showed no significant difference in mtDNA-cn in peripheral blood samples of patients comparted to controls (p = 0.074). In addition, stratified analysis of aged-matched ASD and ADHD patients and controls revealed no significant difference in mtDNA-cn in blood samples between patients and controls (p = 0.214), whereas a significant increase in mtDNA-cn was observed in non-blood samples between patients and controls (p < 0.001). Finally, when the mtDNA-cn was analyzed in blood samples of aged-matched patients with ASD (peripheral blood, leukocytes, and PBMCs) or ADHD (peripheral blood), no significant difference in mtDNA-cn was observed between ASD patients and controls (p = 0.385), while a significant increase in mtDNA-cn was found between ADHD patients and controls (p = 0.033).

Conclusion

In this first meta-analysis of the evaluation of mtDNA-cn in ASD/ADHD, our results show elevated mtDNA-cn in ASD and ADHD, further emphasizing the implication of mitochondrial dysfunction in neurodevelopmental disorders. However, our results indicate that the mtDNA-cn in blood is not reflected in other tissues in ASD/ADHD, and the true relationship between blood-derived mtDNA-cn and ASD/ADHD remains to be defined in future studies. The importance of blood-cell compositions as confounders of blood-based mtDNA-cn measurement and the advantages of salivary mtDNA-cn should be considered in future studies. Moreover, the potential of mtDNA-cn as a biomarker for mitochondrial malfunction in neurodevelopmental disorders deserves further investigations.

Sex differences in conduct and emotional outcomes for young people with hyperactive/inattentive traits and social communication difficulties between 9 and 16 years of age: a growth curve analysis

BACKGROUND

The purpose of this paper is to identify the trajectory of conduct and emotional problems for young people within the general population at four time points (between 9 years 7 months and 16 years 6 months), investigate their relationship with hyperactive/inattentive traits and explore the moderating effect of autistic social traits (ASTs).

METHODS

Data from 9305 individuals involved in The Avon Longitudinal Study of Parents and Children (ALSPAC) study were included. Conduct and emotional problems and hyperactive/inattentive traits were measured by the Strengths and Difficulties Questionnaire. ASTs were assessed using the Social Communication Disorder Checklist. Individual trajectories for conduct and emotional problems were identified via growth curve modelling. Hyperactive/inattentive traits were included within the growth curve model as a time-varying covariate to determine their effect on these outcomes. Finally, participants were split into two groups (below and above clinical threshold ASTs Groups) and multi-group invariance testing was conducted on the data to identify the moderating effect of ASTs on the relationship between hyperactive/inattentive traits and outcomes (i.e. conduct and emotional problems).

RESULTS

Hyperactive/inattentive traits were associated with higher rates of conduct and emotional problems for both boys and girls. The presence of ASTs moderated these relationships for boys, but not for girls, by increasing the risk of boys with hyperactive/inattentive traits developing greater conduct and emotional problems.

CONCLUSIONS

These findings underscore the importance of identifying hyperactive/inattentive traits and ASTs in young people and addressing the increased risk of conduct and emotional problems. Research and clinical implications are explored.

Prevalence and treatment of mental, behavioral, and developmental disorders in children with co-occurring autism spectrum disorder and attention-deficit/hyperactivity disorder: A population-based study

There is a lack of nationally representative studies examining the co-occurrence of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in children. This study examines comorbid mental, behavioral, and developmental disorders (MBDDs) and associated treatment modalities for children with co-occurring ASD and ADHD. Cross-sectional analyses were conducted using data from the pooled 2016-2018 National Survey of Children's Health (sample n = 102,341). Nationally representative prevalences were estimated for sociodemographic variables, comorbidities, psychotropic medication, and behavioral treatment. We assessed multivariable associations between co-occurring ASD + ADHD and MBDDs, use of psychotropic medication, and receipt of behavioral treatment after adjustment for sociodemographic confounders. Compared to children with ASD without co-occurring ADHD, children with ASD + ADHD had higher prevalence of most MBDDs, including anxiety (AOR 4.03 [95% CI 2.77, 4.87]), depression (AOR 3.08 [95% CI 1.77, 5.36]), behavior or conduct problems (AOR 4.06 [95% CI 2.72, 6.06]), and other mental health conditions. Similarly, compared to children with ADHD without ASD, children with ASD + ADHD had higher odds of anxiety (AOR 3.49 [95% CI 2.65, 4.61]), depression (AOR 1.67 [95% CI 1.21, 2.29]), behavior or conduct problems (AOR 2.31 [95% CI 1.68, 3.17]), and other mental health conditions. Children with ASD + ADHD were significantly more likely to take psychotropic medication than children with ASD without ADHD. Among children with ASD + ADHD, males had higher odds of receiving behavioral treatment, whereas older children and adolescents were more likely to take psychotropic medication. A multidisciplinary approach is necessary to support the complex needs of these children.

Pain sensitivity and perceptual sensitivity are associated with severity of emotional dysregulation in children with ADHD: a cross-sectional analysis using the Temperament in Middle Childhood Questionnaire

PURPOSE

Nearly 50% of children with attention-deficit/hyperactivity disorder (ADHD) experience emotional dysregulation or sensory over-responsiveness; this study examines their association.

METHODS

This cross-sectional analysis (n = 124) used data from the Micronutrients for ADHD in Youth (MADDY) Study, which enrolled children aged 6-12 with ADHD and emotional dysregulation. Sensory responsiveness was assessed using two subscales from the factor-analyzed Temperament in Middle Childhood Questionnaire: Pain Sensitivity and Perceptual Sensitivity. Emotional dysregulation was assessed using the Emotional-Problems and Conduct-Problems subscales from the Strengths and Difficulties Questionnaire and a composite score from the Child & Adolescent Symptom Inventory-5. Multivariable linear regression measured the association of pain and perceptual sensitivity with the severity of emotional dysregulation.

RESULTS

In adjusted models, pain sensitivity was positively associated with Emotional Problems (β = 0.97; 95% CI: 0.52, 1.41; p < 0.0001), Conduct Problems (β = 0.83; 95% CI: 0.44, 1.21; p = 0.0001), and CASI-5 composite (β = 0.25; 95% CI: 0.16, 0.34; p < 0.0001). Perceptual sensitivity was positively associated with Emotional Problems (β = 0.75; 95% CI: 0.15, 1.35; p = 0.01) but not Conduct Problems (β = 0.27; 95% CI: -0.24, 0.77; p = 0.30) or CASI-5 composite (β = 0.12; 95% CI: -0.01, 0.24; p = 0.07).

CONCLUSION

Pain sensitivity was associated with the severity of emotional dysregulation in this ADHD sample. To better understand possible causal links, longitudinal studies are warranted.Implications for rehabilitationEmotional dysregulation and sensory over-responsiveness are both common in children with ADHD and contribute to added challenges in school and family life.Two types of sensory over-responsiveness, pain sensitivity and perceptual sensitivity, were associated with emotional dysregulation in children with ADHD in our study.Sensory over-responsiveness may be a modifiable treatment target.

ASD symptoms in adults with ADHD: a comparative study using ADOS-2

In this study, we examined autism spectrum disorder (ASD) symptoms in adults with attention-deficit hyperactivity disorder (ADHD) in comparison with normal controls using the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2). Sixty-three adults with ADHD (mean age, 35.3 years; 38 men) and 31 controls (mean age, 38.7 years; 17 men) completed Module 4 of the ADOS-2, Autism Spectrum Quotient, Conners' Adult ADHD Rating Scale, and Wechsler Adult Intelligence Scale, Third Edition. Adults with ADHD were not clinically diagnosed with ASD, and their ADHD diagnosis was based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria. Between-group comparisons on the scoring patterns revealed significant ASD symptoms present in adults with ADHD, which was congruent with our previous study. Further, item level and correlation analyses showed the possibility that ASD symptoms in adult ADHD comprised of two distinct mechanisms, one qualitatively similar to ASD and the other arising from ADHD characteristics, highlighting the complex nature of ADHD-ASD symptom overlaps.

A data driven machine learning approach to differentiate between autism spectrum disorder and attention-deficit/hyperactivity disorder based on the best-practice diagnostic instruments for autism

Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are two frequently co-occurring neurodevelopmental conditions that share certain symptomatology, including social difficulties. This presents practitioners with challenging (differential) diagnostic considerations, particularly in clinically more complex cases with co-occurring ASD and ADHD. Therefore, the primary aim of the current study was to apply a data-driven machine learning approach (support vector machine) to determine whether and which items from the best-practice clinical instruments for diagnosing ASD (ADOS, ADI-R) would best differentiate between four groups of individuals referred to specialized ASD clinics (i.e., ASD, ADHD, ASD + ADHD, ND = no diagnosis). We found that a subset of five features from both ADOS (clinical observation) and ADI-R (parental interview) reliably differentiated between ASD groups (ASD & ASD + ADHD) and non-ASD groups (ADHD & ND), and these features corresponded to the social-communication but also restrictive and repetitive behavior domains. In conclusion, the results of the current study support the idea that detecting ASD in individuals with suspected signs of the diagnosis, including those with co-occurring ADHD, is possible with considerably fewer items relative to the original ADOS/2 and ADI-R algorithms (i.e., 92% item reduction) while preserving relatively high diagnostic accuracy. Clinical implications and study limitations are discussed.

Driving risks of young drivers with symptoms of attention deficit hyperactivity disorder: association with the dopamine transporter gene VNTR polymorphism

BACKGROUND

Road traffic injuries are a leading cause of death for young adults, and young drivers with higher expression of symptoms of attention deficit-hyperactivity disorder (ADHD) could pose an even greater risk in traffic. Dopaminergic dysfunction has been found to occur in ADHD, with the dopamine transporter (DAT) gene VNTR polymorphism (DAT1 VNTR; rs28363170) being one of the most consistent genetic markers. Thus, we aimed at clarifying how the ADHD symptoms and the DAT1 VNTR relate to risk-taking behaviour in traffic, impulsivity and driving anger in young drivers.

METHOD

We used data of two traffic behaviour study samples (n = 741, mean age = 23.3 ± 7.2 years; n = 995, mean age = 22.9 ± 8.1 years) and the Estonian Children Personality Behaviour and Health Study (ECPBHS; traffic behaviour data n = 1,016, mean age = 25.2 ± 2.1 years). ADHD symptoms were assessed by self-report with the Adult ADHD Self-Report Scale (ASRS v1.1) and impulsivity with the Adaptive and Maladaptive Impulsivity Scale. Traffic behavioural measures were either self-reported (Driver Behaviour Questionnaire, Driving Anger Scale) or obtained from databases (registered accidents and violations).

RESULTS

Drivers with more self-reported ADHD symptoms also reported more risk-taking in traffic and had more of recorded traffic accidents and violations. DAT1 9 R carriers had a higher probability of high traffic risk behaviour only if they also had ADHD symptoms.

CONCLUSION

Higher level of ADHD symptoms is a significant risk factor in traffic, and carrying of the DAT1 9 R allele appears to aggravate these risks.

Early manifestations of genetic risk for neurodevelopmental disorders

BACKGROUND

Attention deficit/hyperactivity disorder (ADHD), autism spectrum disorder (autism) and schizophrenia are highly heritable neurodevelopmental disorders, affecting the lives of many individuals. It is important to increase our understanding of how the polygenic risk for neurodevelopmental disorders manifests during childhood in boys and girls.

METHODS

Polygenic risk scores (PRS) for ADHD, autism and schizophrenia were calculated in a subsample of 15 205 children from the Norwegian Mother, Father and Child Cohort Study (MoBa). Mother-reported traits of repetitive behavior, social communication, language and motor difficulties, hyperactivity and inattention were measured in children at 6 and 18 months, 3, 5 and 8 years. Linear regression models in a multigroup framework were used to investigate associations between the three PRS and dimensional trait measures in MoBa, using sex as a grouping variable.

RESULTS

Before the age of 2, the ADHD PRS was robustly associated with hyperactivity and inattention, with increasing strength up to 8 years, and with language difficulties at age 5 and 8. The autism PRS was robustly associated with language difficulties at 18 months, motor difficulties at 36 months, and hyperactivity and inattention at 8 years. We did not identify robust associations for the schizophrenia PRS. In general, the PRS associations were similar in boys and girls. The association between ADHD PRS and hyperactivity at 18 months was, however, stronger in boys.

CONCLUSIONS

Polygenic risk for autism and ADHD in the general population manifests early in childhood and broadly across behavioral measures of neurodevelopmental traits.

ADHD co-morbidities: A review of implication of gene × environment effects with dopamine-related genes

ADHD is a major burden in adulthood, where co-morbid conditions such as depression, substance use disorder and obesity often dominate the clinical picture. ADHD has substantial shared heritability with other mental disorders, contributing to comorbidity. However, environmental risk factors exist but their interaction with genetic makeup, especially in relation to comorbid disorders, remains elusive. This review for the first time summarizes present knowledge on gene x environment (GxE) interactions regarding the dopamine system. Hitherto, mainly candidate (GxE) studies were performed, focusing on the genes DRD4, DAT1 and MAOA. Some evidence suggest that the variable number tandem repeats in DRD4 and MAOA may mediate GxE interactions in ADHD generally, and comorbid conditions specifically. Nevertheless, even for these genes, common variants are bound to suggest risk only in the context of gender and specific environments. For other polymorphisms, evidence is contradictory and less convincing. Particularly lacking are longitudinal studies testing the interaction of well-defined environmental with polygenic risk scores reflecting the dopamine system in its entirety.

Diagnostic evaluation of patients referred by family physicians with the suspicion of autism spectrum disorder

Current evidence shows that early interventions in children with autism spectrum disorder (ASD) are more efficient and associated with better long-term outcomes. This also highlights the need for early recognition of children with ASD symptoms by family physicians and referral to child psychiatrists. This study aimed to evaluate how family physicians' knowledge about ASD is reflected in clinical practice by making a diagnostic evaluation of the cases referred with suspected ASD. The study included 149 cases that family physicians referred to child psychiatrists regarding the assessment for ASD. Diagnostic evaluation of the subjects was carried out using the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) criteria. Childhood Autism Rating Scale (CARS) and Autism Behavior Checklist (ABC) were used in the evaluation process. Denver II developmental screening inventory was used to evaluate all subjects under six. The mean age of all participants was 39.1 (±13.2) months, and in ASD cases, it was 34.6 (±7.8) months. Of all referred cases, 72,5% were diagnosed according to the DSM-5 criteria. The most common diagnoses were global developmental delay (28.9%), language disorder (15.4%), ASD (15.4%), and attention deficit hyperactivity disorder (8.7%), respectively. The most common reason for referral specified on the consultation note was delayed speech, with a rate of 87.2%. In addition, 148 (99.3%) of the symptoms noted on the referral note were clustered within the DSM-5 ASD A criteria and 19 (12.8%) within the ASD B criteria. Developmental delay was more prominent in cases with ASD when compared to those with global developmental delay and language disorder. The most common diagnosis was a global developmental delay in referred cases, and only some of the symptoms seen in ASD from the referral notes of family physicians stood out as the reason for referral. These results underline the necessity of continuing ASD training for family physicians.

Prevalence of co-occurring autism spectrum disorder and attention deficit/hyperactivity disorder among children in the United States

LAY ABSTRACT

Autism spectrum disorder and attention deficit/hyperactivity disorder are neurodevelopmental disorders that often co-occur in children. However, there are few large, nationally representative studies examining the prevalence of co-occurring autism spectrum disorder and attention deficit/hyperactivity disorder in children. The aim of this study was to estimate the prevalence of parent-reported co-occurring autism spectrum disorder and attention deficit/hyperactivity disorder in the United States and examine associations between having co-occurring autism spectrum disorder and attention deficit/hyperactivity disorder and sociodemographic and household factors. Data were analyzed from the 2016-2018 National Survey of Children's Health. A total of 88,051 children aged 3-17 years old were included in the analysis. Statistical analyses were conducted to assess the associations between sociodemographic and household characteristics and current co-occurrence of autism spectrum disorder and attention deficit/hyperactivity disorder. Approximately 1.2% of children (740,816) aged 3-17 years had co-occurring autism spectrum disorder and attention deficit/hyperactivity disorder. Children who were male, older, reported poor health, or had public or combined public and private health insurance were more likely to have co-occurring autism spectrum disorder and attention deficit/hyperactivity disorder. Conversely, children who were Black, non-Hispanic or multi-racial/other, non-Hispanic were less likely to report co-occurring autism spectrum disorder and attention deficit/hyperactivity disorder than White non-Hispanics. Findings suggest implementing early developmental screening and surveillance for co-occurring autism spectrum disorder and attention deficit/hyperactivity disorder, and coordinating strategies that optimize early identification and intervention for all children suspected of having co-occurring autism spectrum disorder and attention deficit/hyperactivity disorder, particularly those from underrepresented groups.

Deficits in attention, motor control and perception childhood to age 30 years: prospective case-control study of outcome predictors

OBJECTIVE

Investigate predictors of adverse outcome in children with and without attention-deficit/hyperactivity disorder (ADHD) combined with developmental coordination disorder (DCD) at 6 years of age.

DESIGN

Prospective population-based cohort study.

SETTING

Western Sweden.

PARTICIPANTS

From a screening-based population cohort of 589 individuals, 62 (11 female) diagnosed with ADHD+DCD at mean age 6.6 years, and a comparison group of 51 population-matched (10 female) children were followed prospectively.

OUTCOME MEASURES

Drawn from a clinical reassessment at age 9 years of 110 of the 113 individuals, neuropsychiatric symptoms, continuous performance test results and measures of motor function were used as predictors of outcome in linear regression models. Participants were followed in national registers up to 30-31 years of age for outcomes in adulthood. Predictors were regressed onto an adverse outcome score (range 0-7) comprising seven binary endpoints, and when applicable onto each continuous outcome separately (low educational attainment, low occupation level, psychiatric disorder, psychotropic medication prescription, sick pension, high dependence on social benefits and criminal conviction).

RESULTS

Of the 110 individuals, 3 had died. In univariable regression onto the adverse outcome score, the strongest predictors at age 9 years were symptoms of conduct disorder, oppositional defiant disorder, ADHD and motor dysfunction, with an R² around 25%, followed by autistic traits (R²=15%) and depressive symptoms (R²=8%). Combining these six strongest predictors in a multivariable model yielded an adjusted R²=38%. Subgroup analyses were similar, except for a strong association of autistic traits with the adverse outcome score in females (n=20, R²=50%).

CONCLUSION

Several neurodevelopmental symptoms, including ADHD severity at age 9 years, accounted for a considerable amount of the variance in terms of adulthood adverse outcome. Broad neurodevelopmental profiling irrespective of diagnostic thresholds should inform research and clinical practice. The study highlights the importance of considering associated comorbidities and problems in ADHD.

ASD symptoms in adults with ADHD: a preliminary study using the ADOS-2

Attention-deficit/hyperactivity disorder (ADHD) has long been regarded as disparate and mutually exclusive to autism spectrum disorder (ASD) in the Diagnostic and Statistical Manual of Mental Disorders (DSM)-III-R and DSM-IV. However, this idea has become obsolete due to a growing body of evidence suggesting numerous phenotypic and genetic similarities between ADHD and ASD. ASD symptoms or autistic traits in individuals with ADHD have been examined; however, most studies were conducted on children and relied on self- or parent- reports. ASD symptoms assessed with more direct, objective measures, such as the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) in adults with ADHD, remain understudied. In the present study, we used the ADOS-2 to evaluate ASD symptoms in adults with ADHD who were not clinically diagnosed with ASD. Fifty-six adults (mean age 33.9 years, 35 males, intelligence quotient ≥ 85), who were diagnosed with ADHD based on the DSM-5 criteria, completed Module 4 of the ADOS-2. Autism Spectrum Quotient (AQ), Conners' Adult ADHD Rating Scale (CAARS), and Wechsler Adult Intelligence Scale (WAIS)-III were also administered to assess self-rated ASD symptoms, ADHD symptoms, and intelligence, respectively. Overall, 23.3% of participants met the ASD diagnostic classification on the ADOS-2. Social reciprocal interaction scores tended to be higher, while restricted and repetitive behavior scores were low. The scoring patterns and possible overlapping and differing phenotypic characteristics of ADHD and ASD are discussed.

Comorbidity of Attention-Deficit Hyperactivity Disorder and Autism Spectrum Disorders: Current Status and Promising Directions

High rates of co-occurring Attention-Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorders (ASD) suggest common causal pathways, which await elucidation. What is well-established, however, is the negative impact of comorbid ADHD and ASD on outcomes for everyday living, particularly in social interaction and communication and on broader psychopathology. Neurocognitive approaches suggest correlates of comorbidity are rooted in functional connectivity networks associated with executive control. There is support for familial origins, with molecular-genetic studies suggesting a causal role of pleiotropic genes. Further investigation is needed to elucidate fully how genetic risk for ADHD and ASD affects neurodevelopment and to identify structural and functional neural correlates and their behavioral sequelae. Identification of intermediate phenotypes is necessary to advance understanding, which requires studies that include the full spectrum of ASD and ADHD symptom severity, use longitudinal designs and multivariate methods to probe broad constructs, such as executive and social function, and consider other sources of heterogeneity, such as age, sex, and other psychopathology. Randomized efficacy trials targeting comorbid symptomatology are needed to mitigate negative developmental outcomes.

The Monash Autism-ADHD genetics and neurodevelopment (MAGNET) project design and methodologies: a dimensional approach to understanding neurobiological and genetic aetiology

Background

ASD and ADHD are prevalent neurodevelopmental disorders that frequently co-occur and have strong evidence for a degree of shared genetic aetiology. Behavioural and neurocognitive heterogeneity in ASD and ADHD has hampered attempts to map the underlying genetics and neurobiology, predict intervention response, and improve diagnostic accuracy. Moving away from categorical conceptualisations of psychopathology to a dimensional approach is anticipated to facilitate discovery of data-driven clusters and enhance our understanding of the neurobiological and genetic aetiology of these conditions. The Monash Autism-ADHD genetics and neurodevelopment (MAGNET) project is one of the first large-scale, family-based studies to take a truly transdiagnostic approach to ASD and ADHD. Using a comprehensive phenotyping protocol capturing dimensional traits central to ASD and ADHD, the MAGNET project aims to identify data-driven clusters across ADHD-ASD spectra using deep phenotyping of symptoms and behaviours; investigate the degree of familiality for different dimensional ASD-ADHD phenotypes and clusters; and map the neurocognitive, brain imaging, and genetic correlates of these data-driven symptom-based clusters.

Methods

The MAGNET project will recruit 1,200 families with children who are either typically developing, or who display elevated ASD, ADHD, or ASD-ADHD traits, in addition to affected and unaffected biological siblings of probands, and parents. All children will be comprehensively phenotyped for behavioural symptoms, comorbidities, neurocognitive and neuroimaging traits and genetics.

Conclusion

The MAGNET project will be the first large-scale family study to take a transdiagnostic approach to ASD-ADHD, utilising deep phenotyping across behavioural, neurocognitive, brain imaging and genetic measures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-021-00457-3.

Clinical presentations of social communication disorder: A case series

Social Communication Disorder (SCD) is a new DSM-5 diagnostic category poorly understood by clinicians. We describe a case series of four individuals diagnosed with SCD to identify common characteristics and differences in presentations of the disorder. All cases had deficits in the area of social communication, and sub-threshold level of restricted and repetitive behaviours, not sufficient to meet criteria for Autism Spectrum Disorder (ASD). All cases presented with at least one mental health co-morbid condition. There are significant overlaps in clinical presentation between SCD and ASD. It is imperative that accurate diagnostic tools and effective intervention approaches of SCD be developed.

The utility of parent-report screening tools in differentiating autism versus attention-deficit/hyperactivity disorder in school-age children

LAY ABSTRACT

We tested the ability of a short, recently developed parent interview and two widely used parent-report questionnaires to discriminate school-age verbal children with autism spectrum disorder from those with attention-deficit/hyperactivity disorder without autism spectrum disorder (ADHD_w/oASD). These measures included the Autism Symptom Interview - School-Age, the Social Responsiveness Scale - 2nd Edition, and the Social Communication Questionnaire - Lifetime. The classification accuracy of all three parent screeners fell in the moderate range. Accuracy varied by instrument, and the Social Communication Questionnaire - Lifetime questionniare showed the highest accuracy. Children with autism spectrum disorder who were incorrectly classified by all parent screeners did not differ from those correctly classified in regard to demographics, intellectual abilities, nor in any specific clinical area beyond general parent concerns. These findings showed that there are valid screening options for assessing school-age verbal children with autism spectrum disorder versus ADHD_w/oASD. They also underscore the need to assess multiple sources of information for increased accuracy.

The Impact of the Comorbidity of ASD and ADHD on Social Impairment

Children with autism spectrum disorder (ASD) and children with attention deficit/hyperactivity disorder (ADHD) both experience behavioral and social difficulties. Prior research has shown that when these disorders co-occur, behavioral symptoms associated with both disorders may be more severe. There is only limited research on the impact of ASD + ADHD comorbidity on social functioning. The present study investigated social impairment in 282 children diagnosed with ASD, ADHD, or ASD + ADHD. No significant differences in social impairment were found between the ASD and ASD + ADHD groups. This study contributes to extant literature indicating mixed findings in regard to social functioning amidst the ASD + ADHD comorbidity.

The Association Between Autism Symptoms and Child Functioning in a Sample With ADHD Recruited From the Community

Objective: Although autism spectrum disorder (ASD) symptoms are associated with poorer functioning in children with attention-deficit/hyperactivity disorder (ADHD), it is unclear which ASD symptom domains are most impairing. This study investigated whether specific ASD symptom domains were associated with child functioning in children with ADHD. Method: Parents of 164 children with ADHD completed a diagnostic interview to assess ADHD and comorbidities. Parents reported on ASD symptoms (Social Communication Questionnaire) and child quality of life (Pediatric Quality of Life Inventory 4.0). Parents and teachers completed the Strengths and Difficulties Questionnaire (emotional, conduct, and peer problems). Results: Repetitive and stereotyped behaviors were independently associated with emotional (p = .02) and conduct (p = .03) problems, and poorer quality of life (p = .004). Reciprocal social interaction deficits were independently associated with peer problems (p = .03). Conclusion: Reciprocal social interaction deficits and repetitive and stereotyped behaviors are important areas that should be focused on in ADHD assessment and treatment.

Latrophilin-3 disruption: Effects on brain and behavior

Latrophilin-3 (LPHN3), a G-protein-coupled receptor belonging to the adhesion subfamily, is a regulator of synaptic function and maintenance in brain regions that mediate locomotor activity, attention, and memory for location and path. Variants of LPHN3 are associated with increased risk for attention deficit hyperactivity disorder (ADHD) in some patients. Here we review the role of LPHN3 in the central nervous system (CNS). We describe synaptic localization of LPHN3, its trans-synaptic binding partners, links to neurodevelopmental disorders, animal models of Lphn3 disruption in different species, and evidence that LPHN3 is involved in cognition as well as activity and attention. The evidence shows that LPHN3 plays a more significant role in neuroplasticity than previously appreciated.

The efficacy and safety in attention deficit hyperactivity disorder of second-generation antipsychotics and other medications for hyperactivity in children and adolescents with autism: a meta-analysis

Children and adolescents with ASD also have co-occurrence of attention deficit hyperactivity disorder (ADHD) symptoms. ADHD symptoms, especially hyperactivity, greatly increased the severity of autism symptoms. This study concentrated on two widely-used medications: the second generation of antipsychotics (SGAs) and ADHD medication, aiming to conduct a meta-analysis about their effect on hyperactivity, so it would offer some evidence for clinical medication choice. The Medline, Embase, Cochrane Central Register of Controlled Trials and China National Knowledge Infrastructure databases were searched from inception to July 2019 for studies exploring the use of SGAs and ADHD medications in autistic children and adolescents. Double-blind, randomized controlled trials that reported hyperactivity as an outcome were included in the study. A total of thirteen trials with 712 participants were included in our meta-analysis. For SGAs, the standardized mean difference (SMD) of hyperactivity subscale in Aberrant behavior checklist scale or conners rating scales was 0.59, 95% confidence interval (CI): 0.23-0.96, I2 = 74%, Q = 15.34, P < 0.01. For ADHD medications, SMD was -0.66, with 95% CI: -0.99 to 0.33, I2 = 53%, Q = 15.02, P = 0.04. As for adverse events, in the SGAs group, somnolence had the largest effect size, risk ratio = 5.62, 95% CI: 3.20- 9.87 (I2 = 0%, Q = 2.45, P = 0.65). In ADHD group, the side effect of decreased appetite showed the largest effect size (risk ratio = 2.63, 95% CI = 0.99-7.01, I2 = 65.7%, Q = 11.66, P = 0.02). Both ADHD medications and SGAs were effective in dealing with hyperactivity in children and adolescents with autism but were shown to increase the risk of decreased appetite, somnolence, headache and nausea or vomiting. The clinical use of these medications should carefully weigh the benefits and risks.

A Review of the Default Mode Network in Autism Spectrum Disorders and Attention Deficit Hyperactivity Disorder

Functional magnetic resonance imaging (fMRI) has been widely used to examine the relationships between brain function and phenotypic features in neurodevelopmental disorders. Techniques such as resting-state functional connectivity (FC) have enabled the identification of the primary networks of the brain. One fMRI network, in particular, the default mode network (DMN), has been implicated in social-cognitive deficits in autism spectrum disorders (ASD) and attentional deficits in attention deficit hyperactivity disorder (ADHD). Given the significant clinical and genetic overlap between ASD and ADHD, surprisingly, no reviews have compared the clinical, developmental, and genetic correlates of DMN in ASD and ADHD and here we address this knowledge gap. We find that, compared with matched controls, ASD studies show a mixed pattern of both stronger and weaker FC in the DMN and ADHD studies mostly show stronger FC. Factors such as age, intelligence quotient, medication status, and heredity affect DMN FC in both ASD and ADHD. We also note that most DMN studies make ASD versus ADHD group comparisons and fail to consider ASD+ADHD comorbidity. We conclude, by identifying areas for improvement and by discussing the importance of using transdiagnostic approaches such as the Research Domain Criteria (RDoC) to fully account for the phenotypic and genotypic heterogeneity and overlap of ASD and ADHD.

Genetic Overlap Between Attention Deficit/Hyperactivity Disorder and Autism Spectrum Disorder in SHANK2 Gene

Background: Recent findings indicated a high comorbidity between attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), as well as shared genetic influences on them. The latter might contribute at least partly to the former clinical scenario. This study aimed at investigating whether SHANK genes were potential pleiotropic genes to the two said disorders, underlying their genetic overlap.

Methods: This study recruited 298 boys with ADHD (including 256 family trios of 1 ADHD boy and his 2 biological parents), 134 boys with ASD, 109 boys with both ADHD and ASD, and 232 typically developing boys as community controls. They were aged between 6 and 11 years old.

Results: There was no significant difference in allele frequency of a number of single nucleotide polymorphisms (SNPs) in SHANK2/SHANK3 between the three clinical groups (ADHD, ASD, and ADHD + ASD) and between the two control groups (community controls and pseudo-controls), respectively. The three clinical groups and the two control groups were thus, respectively, combined. A comparison between the two aggregated samples identified significant evidence of disease association for three SHANK2 SNPs with both ADHD and ASD, even after multiple testing correction: rs11236616 (OR = 0.762, permuted p = 0.0376), rs7106631 (OR = 0.720, permuted p = 0.0034), and rs9888288 (OR = 0.770, permuted p = 0.0407). Comparisons among individual groups pointed to a similar trend of findings.

Conclusion:SHANK2 could be considered a potential pleiotropic gene underlying the genetic overlap between ADHD and ASD. This might contribute partly to their high comorbidity in the afflicted children.

Sensory Modulation Disorder and its Neural Circuitry in Adults with ADHD: A Pilot Study

Compared to healthy controls (HCs), individuals with attention-deficit/hyperactivity disorder (ADHD) exhibit more symptoms of sensory processing disorder (SPD), which is associated with difficulties in educational and social activities. Most studies examining comorbid SPD-ADHD have been conducted with children and have not explored relations to brain volumes. In this pilot study, we assessed a subtype of SPD, sensory modulation disorder (SMD), and its relation to select brain volumes in adults with ADHD. We administered part of the Sensory Processing 3-Dimensions Scale (SP3D) to assess subtypes of SMD and collected structural imaging scans from 25 adults with ADHD and 29 healthy controls (HCs). Relative to HCs, subjects with ADHD scored higher on sensory craving (SC) and sensory under-responsivity (SUR) subscales. Although sensory over-responsivity (SOR) was marginally higher, this was no longer true when accounting for co-occurring anxiety. In individuals with ADHD, both SC and SUR were positively associated with amygdalar volume, SUR was also positively associated with striatal volume, whereas SOR was negatively associated with posterior ventral diencephalon volume. These preliminary findings suggest that SC and SUR may be characteristic of ADHD while SOR may be driven by co-occurring anxiety. Because different modalities were associated with different brain volumes, our findings also suggest that the modalities may involve unique neural circuits, but with a partial overlap between SC and SUR. These pilot data provide support for conducting studies examining SMD in larger samples of adults with ADHD to determine reproducibility, applicability and implications of these findings.

Attention-deficit/hyperactivity disorder with developmental coordination disorder: 24-year follow-up of a population-based sample

BACKGROUND

Although the body of research concerning neurodevelopmental disorders is vast, there is a scarcity of longitudinal studies beyond late adolescence, and of studies taking co-existing disorders into account. The present study aimed to investigate outcome in adulthood for children with attention-deficit/hyperactivity disorder (ADHD) combined with developmental coordination disorder (DCD) diagnosed at 6.6 years of age.

METHODS

Out of a screening-based population cohort of 589 individuals, 62 (10 female) diagnosed with ADHD+DCD at mean age 6.6 years naïve to stimulant treatment were followed into adulthood through national registries. Results were compared to a screen- and assessment negative population matched group from the same cohort (PM group, n = 51) and a registry-matched (RM group, n = 410) group of the same county and age.

RESULTS

At 30 to 31 years of age, five deaths had occurred; one in the ADHD+DCD group and two each in the comparison groups. In time to event analyses of the composite outcome of any psychiatric disorder, psychotropic prescription, sick pension or criminal sentence, events occurred at a significantly higher rate in the ADHD+DCD group (p = 0.0032, vs PM group p = 0.0115, vs RM group p = 0.0054). The ADHD+DCD group had significantly higher rates of psychiatric diagnoses, prescriptions of psychoactive medications and occurrence of sick pension than both comparison groups. Further, the ADHD+DCD group had significantly lower educational attainment compared to both comparison groups, more years with unemployment, and overall higher welfare recipiency. Rates of pain diagnoses and analgesic prescriptions did not separate the groups.

CONCLUSION

ADHD+DCD entailed a less favorable outcome in adulthood compared to a non-clinical comparison group and a registry-matched population. Neurodevelopmental disorder diagnosed upon school entry is of prognostic utility with respect to function in adulthood, and warrants early identification and management.

Associations Between Limbic System White Matter Structure and Socio-Emotional Functioning in Children with ADHD + ASD

Children with attention deficit/hyperactivity disorder (ADHD) combined with autism spectrum disorder (ASD) symptoms (ADHD + ASD) have poorer social and emotional functioning than those with ADHD alone. However, no studies have specifically examined the associations between ASD symptoms, measures of social and emotional functioning and limbic system white matter microstructure. Tractography on the cingulum, uncinate fasciculus and fornix were performed for 151 children with (N = 78) and without (N = 73) ADHD. Participants in the ADHD group who scored 11 or above on the Social Communication Questionnaire were classified as the ADHD + ASD group (N = 16). Significant differences in mean cingulum FA were present between the control group and the ADHD (all) group, however, no significant differences were seen between the ADHD and ADHD + ASD groups. Despite this, significant associations were seen between mean FA of the left cingulum and emotional problems for the ADHD + ASD group. Results give greater insights into the specific biological basis of emotional problems in the ADHD + ASD group, indicating that the cingulum may play a role.

Autistic spectrum disorder symptoms in children and adolescents with attention-deficit/hyperactivity disorder: a meta-analytical review

BACKGROUND

Research identifies highly variable prevalence estimates for autism spectrum disorder (ASD) in children and adolescents with attention deficit hyperactivity disorder (ADHD), particularly between community and clinical samples, warranting quantitative meta-analyses to investigate the true prevalence of ASD in children and adolescents with ADHD.

METHODS

Studies were identified through a systematic literature search of PsycINFO, MEDLINE and Web of Science through January 2018. Twenty-two publications met inclusion criteria (total N = 61 985). Two random effects meta-analyses were conducted: (1) to identify the proportion of children and adolescents with ADHD that met criteria for ASD; and (2) to compare the severity of dimensionally-measured ASD symptomology in children and adolescents with and without ADHD.

RESULTS

The overall pooled effect for children and adolescents with ADHD who met threshold for ASD was 21%. There was no significant difference between community samples (19%) and clinical samples (24%) or between US studies v. those from other countries. Children and adolescents with ADHD had substantially more dimensionally-measured ASD traits compared with those who did not have ADHD (d = 1.23).

CONCLUSION

The findings provide further evidence that ADHD and ASD are associated in nature. Clinical and research implications are discussed.

Examining the autistic traits in children and adolescents diagnosed with attention-deficit hyperactivity disorder and their parents

BACKGROUND

Attention-Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) are two of the most frequently-observed neurodevelopmental disorders. Autistic traits are detected frequently in children who have ADHD. This study aimed to examine autism symptoms in children diagnosed with ADHD and their parents; and also, to investigate parental risk factors that increase autistic traits in children. Besides the risk factors related to pregnancy, birth and developmental history were examined.

METHODS

Two groups were created consisting of 66 children diagnosed with ADHD and 33 children not diagnosed with ADHD and their parents. Autism symptoms were screened with the Autism Behavior Checklist (ABC) in children, and Autism Spectrum Quotient (AQ) in parents. Also, Adult ADD/ADHD DSM-IV Based Diagnostic Screening and Rating Scale and Wender Utah Rating Scale (WURS) were used to determine ADHD symptoms in parents.

RESULTS

It was determined that there were more autism symptoms in children who were diagnosed with ADHD than in the control group without ADHD. There were more autistic symptoms in boys and the presence of Oppositional Defiant Disorder (ODD). Although there were more ADHD symptoms in the parents of children diagnosed with ADHD, it was determined that they did not differ from parents in the control group in terms of autism symptoms. It was also determined that maternal and paternal ADHD symptoms were predictive for autism symptoms in children. It was also shown that maternal smoking during pregnancy is associated with more autistic traits.

CONCLUSION

ASD and ADHD show high levels of comorbidity. The etiology remains unclear. Both ADHD and ASD show strong hereditary transition. We found that maternal and paternal ADHD symptoms predict autism symptoms in children with ADHD. However, more studies are needed to reveal the etiology.

Spontaneous theory of mind in adults with attention-deficit/hyperactivity disorder

Spontaneous theory of mind (ToM) is an unconscious and automatic understanding of others' mental states. Recently, individuals with attention-deficit hyperactivity disorder (ADHD) have been shown to have social and communication difficulties, and ToM in ADHD has come under scrutiny. Although some studies have employed explicit ToM tasks to this end with contradictory results, none, to our knowledge, has investigated spontaneous ToM in individuals with ADHD. Therefore, we performed this study to examine implicit mentalizing in adults with ADHD using the anticipatory-looking paradigm designed by Senju et al. (2009) with a sample of 24 adults with ADHD and 18 neurotypical adults. The total fixation times to three areas of interest, i.e., the actor and the false-belief congruent and incongruent sides of the scene were measured. We found that neither group showed looking bias toward either the false-belief congruent or incongruent side. We interpret that this similar gaze pattern and the absence of looking bias to the false-belief incongruent side in both groups is indicative of intact implicit ToM in adults with ADHD. Adults with ADHD looked significantly less at the actor than did neurotypical individuals, possibly due to inattention and further experimental modifications should be considered.

Detecting Autism Spectrum Disorder in Children With ADHD and Social Disability

Objective: The social disability associated with ADHD often makes diagnostic and treatment decision making challenging. This protocol investigates the test performance of the Autism Mental Status Exam (AMSE) in detecting autism spectrum disorder (ASD) in a sample of 45 children with ADHD and ASD symptomatology. The AMSE is a brief ASD diagnostic assessment administered in the context of a clinical exam. Method: All participants received a developmental evaluation, including the AMSE, followed by independent gold standard diagnostic assessments including the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview-Revised (ADI-R). Results: Receiver operating characteristics (ROC) curve analysis indicated strong sensitivity and specificity in this population. Optimal cutoff scores are provided. Conclusion: The AMSE holds promise as a brief ASD assessment tool for children with ADHD and ASD symptomatology and as a guide for treatment and referral decisions at the point of care.

The Co-Occurrence of Autism Spectrum Disorder in Children With ADHD

Objective: Children with ADHD frequently present with autism spectrum disorder (ASD) symptomatology, yet there is a notable gap in the treatment needs of this subpopulation, including whether the presence of ASD may be associated with more severe ADHD symptoms. Method: Data from the 2014 National Survey of the Diagnosis and Treatment of ADHD and Tourette Syndrome (n = 2,464) were used to compare children diagnosed with ADHD and ASD with children with ADHD, but not ASD. Children were classified as needing treatment if it was received or their parents reported it was needed, but not received. Results: Approximately one in eight children currently diagnosed with ADHD was also diagnosed with ASD. Children diagnosed with both disorders had greater treatment needs, more co-occurring conditions, and were more likely to have a combined hyperactive/impulsive and inattentive ADHD subtype. Conclusion: These findings highlight the complexity of children diagnosed with both ADHD and ASD.

Structural brain abnormalities in children and adolescents with comorbid autism spectrum disorder and attention-deficit/hyperactivity disorder

Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) share high rates of comorbidity, with the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition now acknowledging the comorbid diagnosis of ASD and ADHD. Although structural abnormalities in the prefrontal cortex, cerebellum, and basal ganglia occur in both ASD and ADHD, no structural studies have focused exclusively on patients with comorbid ASD and ADHD. We thus aimed to clarify the structural features and developmental changes in patients with comorbid ASD and ADHD in a relatively large sample from two sites. Ninety-two patients were age-matched to 141 typically developing (TD) controls (age range: 5-16 years) and assessed for volumetric characteristics using structural magnetic resonance imaging (i.e. surface-based morphometry). While there were no significant differences in prefrontal cortex, cerebellum, and basal ganglia volumes, patients with ASD and ADHD exhibited significantly lower left postcentral gyrus volumes than TD controls. We observed significantly lower postcentral gyrus volumes exclusively in children and preadolescents, and not in adolescents. Our findings suggest that abnormal somatosensory, attributed to delayed maturation of the left postcentral gyrus, leads to the core symptoms experienced by patients with comorbid ASD and ADHD.

Co-Occurrence of ASD and ADHD Traits in an Adult Population

Objective: ADHD and autism spectrum disorder (ASD) can be viewed as the extreme end of traits found in the general population. Clinical and genetic studies suggest that ADHD and ASD often co-occur and share genetic susceptibility. The aim of this study was to examine co-occurrence of ADHD and ASD traits in the general population. Method: In total, 334 participants were recruited from a population-based sample. Four questionnaires assessing current and retrospective ADHD and ASD traits were administered online: the Adult ADHD Self-Report Scale (ASRS) Symptom Checklist, the Wender Utah Rating Scale (WURS-25), the Broad Autism Phenotype Questionnaire (BAPQ), and the Autism Spectrum Quotient (AQ). Results: A significant correlation was found between ADHD and autistic traits. In particular, higher inattention and overall ADHD scores were associated with self-reported deficits in communication and social skills. Conclusion: Our findings are similar to results from studies on clinical populations, suggesting that ADHD and ASD might share common etiology.

AdCom study-adolescent communication group therapy for externalising disorders

BACKGROUND

Communication difficulties are associated with oppositional symptoms in young people. We hypothesise that a communication group intervention will reduce oppositional symptoms in young people. Previous research on communication and social skills training in young people with externalising disorders is limited.

AIMS

We aimed to (1) develop and describe a group communication intervention to promote social competence in adolescents with behaviour difficulties, for use in CAMHS with those with attention-deficit/hyperactivity disorder (ADHD)/externalising disorders, and (2) collect pilot data on the effectiveness of this intervention.

METHODS

We developed and delivered a programme of eight sessions to eight adolescents aged 12 to 13 years. We describe the intervention and challenges running the programme. We present pilot study data on pre- and post-oppositional symptoms.

RESULTS

Our programme was relatively well attended; pilot data indicated a small reduction in oppositional symptoms in all participants. Challenges in running the group were noted.

CONCLUSIONS

Our pilot study data suggest that further research is needed to study the effects of a communication group intervention on oppositional symptoms in a larger number of adolescents.

Genetic Causes and Modifiers of Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is one of the most prevalent neurodevelopmental disorders, affecting an estimated 1 in 59 children. ASD is highly genetically heterogeneous and may be caused by both inheritable and de novo gene variations. In the past decade, hundreds of genes have been identified that contribute to the serious deficits in communication, social cognition, and behavior that patients often experience. However, these only account for 10-20% of ASD cases, and patients with similar pathogenic variants may be diagnosed on very different levels of the spectrum. In this review, we will describe the genetic landscape of ASD and discuss how genetic modifiers such as copy number variation, single nucleotide polymorphisms, and epigenetic alterations likely play a key role in modulating the phenotypic spectrum of ASD patients. We also consider how genetic modifiers can alter convergent signaling pathways and lead to impaired neural circuitry formation. Lastly, we review sex-linked modifiers and clinical implications. Further understanding of these mechanisms is crucial for both comprehending ASD and for developing novel therapies.

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

BACKGROUND

Traits of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are strongly associated in children and adolescents, largely due to genetic factors. Less is known about the phenotypic and aetiological overlap between ADHD and ASD traits in adults.

METHODS

We studied 6866 individuals aged 20-28 years from the Swedish Study of Young Adult Twins. Inattention (IA) and hyperactivity/impulsivity (HI) were assessed using the WHO Adult ADHD Self-Report Scale-V1.1. Repetitive and restricted behaviours (RRB) and social interaction and communication (SIC) were assessed using the Autism-Tics, ADHD, and other Comorbidities inventory. We used structural equation modelling to decompose covariance between these ADHD and ASD trait dimensions into genetic and shared/non-shared environmental components.

RESULTS

At the phenotypic level, IA was similarly correlated with RRB (r = 0.33; 95% Confidence Interval (CI) 0.31-0.36) and with SIC (r = 0.32; 95% CI 0.29-0.34), whereas HI was more strongly associated with RRB (r = 0.38; 95% CI 0.35-0.40) than with SIC (r = 0.24; 95% CI 0.21-0.26). Genetic and non-shared environmental effects accounted for similar proportions of the phenotypic correlations, whereas shared environmental effects were of minimal importance. The highest genetic correlation was between HI and RRB (r = 0.56; 95% 0.46-0.65), and the lowest was between HI and SIC (r = 0.33; 95% CI 0.23-0.43).

CONCLUSIONS

We found evidence for dimension-specific phenotypic and aetiological overlap between ADHD and ASD traits in adults. Future studies investigating mechanisms underlying comorbidity between ADHD and ASD may benefit from exploring several symptom-dimensions, rather than considering only broad diagnostic categories.

A Transdiagnostic Examination of Self-Regulation: Comparisons Across Preschoolers with ASD, ADHD, and Typically Developing Children

The purpose of the current study was to identify profiles of self-regulation across executive functioning (EF) and emotion regulation (ER) and examine profiles's impact on treatment outcomes. Participants included 100 preschoolers (M_age = 4.73, 75% Male, 79% Hispanic) including 37 with autism spectrum disorder and attention-deficit/hyperactivity disorder (ASD+ADHD), 32 with ADHD-only, and 31 typically developing children. Parents and teachers reported on children's EF, ER, ASD, and ADHD symptoms. Children were administered an EF battery and observed for ER during a frustration task. Children participated in an intensive behavioral summer treatment program (STP-PreK) aimed at improving school readiness across behavioral, academic, and self-regulation domains. Latent profile analyses produced 4 profiles: (a) Low ER and EF Deficits, (b) High ER Deficits, (c) High EF Deficits, and (d) Moderate ER and EF Deficits. ASD and ADHD symptoms predicted lower membership probability within the Low ER and EF Deficits Profile and higher membership probability within the Moderate ER and EF Deficits Profile. However, only ASD symptoms predicted membership within the High EF Deficits Profile. Only ADHD symptoms predicted membership within the High ER Deficits Profile. Even after accounting for diagnostic symptoms, profile membership was predictive of treatment response across behavioral and academic domains. Children in the High EF Deficits Profile experienced the largest gains. Results highlight the specificity of self-regulation deficits within and across diagnoses. Self-regulation profiles demonstrated clinical utility in predicting treatment response above traditional symptom based classifications, providing evidence for the use of transdiagnostic approaches.

Distinct Methylphenidate-Evoked Response Measured Using Functional Near-Infrared Spectroscopy During Go/No-Go Task as a Supporting Differential Diagnostic Tool Between Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder Comorbid Children

Attention deficit/hyperactivity disorder (ADHD) has been frequently reported as co-occurring with autism spectrum disorder (ASD). However, ASD-comorbid ADHD is difficult to diagnose since clinically significant symptoms are similar in both disorders. Therefore, we propose a classification method of differentially recognizing the ASD-comorbid condition in ADHD children. The classification method was investigated based on functional brain imaging measured by near-infrared spectroscopy (NIRS) during a go/no-go task. Optimization and cross-validation of the classification method was carried out in medicated-naïve and methylphenidate (MPH) administered ADHD and ASD-comorbid ADHD children (randomized, double-blind, placebo-controlled, and crossover design) to select robust parameters and cut-off thresholds. The parameters could be defined as either single or averaged multi-channel task-evoked activations under an administration condition (i.e., pre-medication, post-MPH, and post-placebo). The ADHD children were distinguished by significantly high MPH-evoked activation in the right hemisphere near the midline vertex. The ASD-comorbid ADHD children tended to have low activation responses in all regions. High specificity (86 ± 4.1%; mean ± SD), sensitivity (93 ± 7.3%), and accuracy (82 ± 1.6%) were obtained using the activation of oxygenated-hemoglobin concentration change in right middle frontal, angular, and precentral gyri under MPH medication. Therefore, the significantly differing MPH-evoked responses are potentially effective features and as supporting differential diagnostic tools.

Increased risk of ADHD in families with ASD

Attention Deficit and Hyperactive Disorder (ADHD) and Autism Spectrum Disorders (ASD) are frequent comorbid neurodevelopmental conditions and the overlap between both disorders remains to be delineated. A more complete understanding of the shared genetic and environmental factors is needed. Using a family-based method, we evaluated the risk of ADHD in a group of relatives with an ASD proband (ASD-) and a group of relatives with an ASD and ADHD proband (ASD+). We enrolled 1245 individuals in the study: 499 probands, their 746 first-degree relatives and 140 controls. We used a multivariate generalized estimating equation (GEE) model, in which the dependent variable was the ADHD diagnosis in the relatives and the independent variable the ASD+ or ASD- in probands. We adjusted for sociodemographic factors (age, sex, IQ) and for the nature of the familial relationship with the affected proband (parent or sibling). Among the probands, there were 287 ASD- and 212 ASD+ individuals. ADHD was more frequent in relatives (19%) than in the control group (7%) (p = 0.001). The risk of ADHD was higher in the ASD+ relatives group than in the ASD- relatives group (GEE model OR 1.58 [95% CI 1.04-2.38], p = 0.032). This result was found in parents (OR 1.96 [95% CI  1.14-3.36], but not in siblings (OR 1.28 [95% CI 0.84-1.94], p = 0.434). Our study provides a representative estimate of the family distribution of ADHD in relatives of ASD probands but supports the modest effect of shared genetic and environmental factors between both disorders.

Meta-Analysis of Sex Differences in Social and Communication Function in Children With Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder

Background: Sex differences in the prevalence of neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are well documented, but studies examining sex differences in social and communication function remain limited and inconclusive. Objectives: The objective of this study is to conduct a meta-analysis of sex differences in social-communication function in children with ASD or ADHD and typically developing controls. Methods: Using PRISMA, a search was performed on Medline and PSYCHINFO on English-language journals (2000-2017) examining sex differences in social and communication function in ASD and ADHD compared to controls. Inclusion criteria: 1) peer reviewed journal articles, 2) diagnosis of ASD or ADHD and controls, 3) age 6-18 years, 4) measures of social-communication function, and 5) means, standard deviations, and sample sizes reported in order to calculate standardized mean differences (SMD). Results: Eleven original/empirical studies met inclusion criteria for ASD and six for ADHD. No significant sex differences were found between ASD and controls in social (SMD = -0.43; p = 0.5; CI: -1.58-0.72), or communication function (SMD = 0.86; p = 0.5 CI; -1.57--3.30) and between ADHD and controls in social function (SMD = -0.68: p = 0.7, CI: -4.17-2.81). No studies evaluated sex differences in communication in ADHD. Significant heterogeneity was noted in all analyses. Type of measure may have partially accounted for some variability between studies. Conclusions: The meta-analysis did not detect sex differences in social and communication function in children with ASD and ADHD; however, significant heterogeneity was noted. Future larger studies, controlling for measure and with adequate numbers of female participants are required to further understand sex differences in these domains.

Overlaps and distinctions between attention deficit/hyperactivity disorder and autism spectrum disorder in young adulthood: Systematic review and guiding framework for EEG-imaging research

Attention deficit/hyperactivity disorders (ADHD) and autism spectrum disorders (ASD) frequently co-occur. However, we know little about the neural basis of the overlaps and distinctions between these disorders, particularly in young adulthood - a critical time window for brain plasticity across executive and socioemotional domains. Here, we systematically review 75 articles investigating ADHD and ASD in young adult samples (mean ages 16-26) using cognitive tasks, with neural activity concurrently measured via electroencephalography (EEG) - the most accessible neuroimaging technology. The majority of studies focused on event-related potentials (ERPs), with some beginning to capitalise on oscillatory approaches. Overlapping and specific profiles for ASD and ADHD were found mainly for four neurocognitive domains: attention processing, performance monitoring, face processing and sensory processing. No studies in this age group directly compared both disorders or considered dual diagnosis with both disorders. Moving forward, understanding of ADHD, ASD and their overlap in young adulthood would benefit from an increased focus on cross-disorder comparisons, using similar paradigms and in well-powered samples and longitudinal cohorts.

Social difficulties in youth with autism with and without anxiety and ADHD symptoms

Social difficulties inherent to autism spectrum disorder are often linked with co-occurring symptoms of anxiety and attention deficit hyperactivity disorder (ADHD). The present study sought to examine the relation between such co-occurring symptoms and social challenges. Parents of adolescents with autism (N = 113) reported upon social challenges via the social responsiveness scale (SRS) and anxiety and ADHD symptomatology via the Child Behavior Checklist. Results revealed differences in SRS scores across co-occurring symptom subgroups (Anxiety, ADHD, Both, Neither)-namely, adolescents with autism and anxiety as well as those with autism, anxiety, and ADHD showed greater scores on the SRS than the other groups. Implications for research and clinical practice are discussed and recommendations are offered. Autism Research 2018, 11: 1679-1689. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Anxiety and attention deficit hyperactivity disorder (ADHD) symptoms are related to greater social challenges for adolescents with autism spectrum disorder. The present study found that autism with anxiety and autism with anxiety and ADHD, was related to greater social difficulties than autism alone. Findings provide further support for the intertwined nature of anxiety and ADHD symptoms in autism. What this may mean for research and clinical practice is considered and recommendations are suggested.

Attentional Mechanisms in Autism, ADHD, and Autism-ADHD Using a Local-Global Paradigm

OBJECTIVE

Cognitive flexibility or attentional set-shifting capacity has long been considered a core area of executive dysfunction for individuals with autism. Whether these difficulties are due to higher-level attentional difficulties associated with comorbid ADHD remains unclear.

METHOD

The current study compared the performance of 48 participants with autism, ADHD, autism-ADHD, and a comparison group ( N = 12 per group) on a set-shifting task, which included a local-global paradigm.

RESULTS

Results of this study revealed that participants with attentional difficulties (autism + ADHD and ADHD alone) exhibited a significant shifting cost (difference between maintaining and shifting attention).

CONCLUSION

Attentional difficulties associated with ADHD may be associated with an enhanced attentional shifting cost. Implications of these results were discussed in relation to screening for ADHD symptoms in studies of individuals with autism which seek to determine the neuropsychological profile of this condition.

Parents of children with disabilities: A systematic review of parenting interventions and self-efficacy

BACKGROUND

An increasing body of empirical evidence suggests that early intervention has positive outcomes for parents of children with neurodevelopmental disabilities. Parental self-efficacy has been used as an outcome measure in some empirical studies; however, there is a lack of evidence of the impact of parent training programmes on parenting self-efficacy beliefs.

OBJECTIVES

This systematic review sought to assess the effectiveness of parenting interventions to increase parental self-efficacy levels in parents of young children with neurodevelopmental disabilities.

METHOD

We conducted a broad literature search, which included grey literature, such as dissertations and unpublished conference presentations, to identify all relevant prospective studies reporting on our study objective. Articles were selected for inclusion using predefined criteria and data were extracted onto a purposely designed data extraction form. Twenty-five articles met our search criteria. We extracted parenting self-efficacy scores before, and on, completion of parenting interventions and performed a meta-analysis using standardised mean difference. We also conducted a risk of bias assessment for all the included studies.

RESULTS

Parent training programmes resulted in a statistically significant increase in parental self-efficacy levels (standardised mean difference, 0.60 [95% confidence interval {CI}, 0.38-0.83]; I2, 74%) relative to baseline measurements. Parents of children younger than 5 years demonstrated the highest increase in levels of parental self-efficacy after parenting interventions. Furthermore, this review showed that psychologists and other healthcare practitioners are successfully able to implement training programmes that enhance parenting self-efficacy.

CONCLUSION

Parent training programmes are effective in increasing parental self-efficacy in parents of children with neurodevelopmental disabilities.

Live fast, die young? A review on the developmental trajectories of ADHD across the lifespan

Attention-deficit/hyperactivity disorder (ADHD) is highly heritable and the most common neurodevelopmental disorder in childhood. In recent decades, it has been appreciated that in a substantial number of cases the disorder does not remit in puberty, but persists into adulthood. Both in childhood and adulthood, ADHD is characterised by substantial comorbidity including substance use, depression, anxiety, and accidents. However, course and symptoms of the disorder and the comorbidities may fluctuate and change over time, and even age of onset in childhood has recently been questioned. Available evidence to date is poor and largely inconsistent with regard to the predictors of persistence versus remittance. Likewise, the development of comorbid disorders cannot be foreseen early on, hampering preventive measures. These facts call for a lifespan perspective on ADHD from childhood to old age. In this selective review, we summarise current knowledge of the long-term course of ADHD, with an emphasis on clinical symptom and cognitive trajectories, treatment effects over the lifespan, and the development of comorbidities. Also, we summarise current knowledge and important unresolved issues on biological factors underlying different ADHD trajectories. We conclude that a severe lack of knowledge on lifespan aspects in ADHD still exists for nearly every aspect reviewed. We encourage large-scale research efforts to overcome those knowledge gaps through appropriately granular longitudinal studies.

Shared endo-phenotypes of default mode dsfunction in attention deficit/hyperactivity disorder and autism spectrum disorder

Categorical diagnoses from the Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD) manuals are increasingly found to be incongruent with emerging neuroscientific evidence that points towards shared neurobiological dysfunction underlying attention deficit/hyperactivity disorder and autism spectrum disorder. Using resting-state functional magnetic resonance imaging data, functional connectivity of the default mode network, the dorsal attention and salience network was studied in 1305 typically developing and diagnosed participants. A transdiagnostic hierarchical Bayesian modeling framework combining Indian Buffet Processes and Latent Dirichlet Allocation was proposed to address the urgent need for objective brain-derived measures that can acknowledge shared brain network dysfunction in both disorders. We identified three main variation factors characterized by distinct coupling patterns of the temporoparietal cortices in the default mode network with the dorsal attention and salience network. The brain-derived factors were demonstrated to effectively capture the underlying neural dysfunction shared in both disorders more accurately, and to enable more reliable diagnoses of neurobiological dysfunction. The brain-derived phenotypes alone allowed for a classification accuracy reflecting an underlying neuropathology of 67.33% (+/-3.07) in new individuals, which significantly outperformed the 46.73% (+/-3.97) accuracy of categorical diagnoses. Our results provide initial evidence that shared neural dysfunction in ADHD and ASD can be derived from conventional brain recordings in a data-led fashion. Our work is encouraging to pursue a translational endeavor to find and further study brain-derived phenotypes, which could potentially be used to improve clinical decision-making and optimize treatment in the future.