Age-related differences in delta-beta phase-amplitude coupling in autistic individuals.

OBJECTIVE: We aim to investigate the relationship between the core symptoms of autism, anxiety levels, and attention deficit hyperactivity disorder (ADHD) traits, and a non-autism-specific, neurophysiological metric, the Delta-Beta phase-amplitude coupling (PAC), extracted from the resting-state EEG for autistic and non-autistic populations across three different age groups (children, adolescents, and adults). METHODS: We analyze the eyes-open resting-state EEG of 371 individuals. We applied a phase de-biasing PAC algorithm expected to result in a more accurate PAC estimate than other PAC methodologies available in the literature. RESULTS: In the adult group, we found a significant increase of the delta-beta PAC in the autistic subgroup who met the Autism Diagnostic Observation Schedule-2 (ADOS-2) Autism Diagnostic Interview-Revised (ADR-R) ADOS-2/ADI-R threshold compared to non-autistic individuals. The differences seem age-specific since we found no statistically significant differences in the children and adolescent populations. Moreover, we found a significant positive correlation with the restricted and repetitive behaviours score of the ADOS-2 diagnostic instrument and with ADHD hyperactivity/impulsivity in the entire autistic cohort. CONCLUSIONS: The neurophysiological differences we found only in the autistic individuals that meet the thresholds also point out the need for future studies that look for autistic neurodiverse subgroups beyond age. SIGNIFICANCE: The delta-beta debiasing PAC (dPAC) may potentially serve as a severity biomarker in the autistic population.

Twenty-four-month effortful control predicts emerging autism characteristics.

Longitudinal research can assess how diverging development of multiple cognitive skills during infancy, as well as familial background, are related to the emergence of neurodevelopmental conditions. Sensorimotor and effortful control difficulties are seen in infants later diagnosed with autism; this study explored the relationships between these skills and autism characteristics in 340 infants (240 with elevated familial autism likelihood) assessed at 4-7, 8-10, 12-15, 24, and 36 months. We tested: (1) the relationship between parent-reported effortful control (Rothbart's temperament questionnaires) and sensorimotor skills (Mullen Scales of Early Learning), using random intercept cross-lagged panel modelling; (2) whether household income and maternal education predicted stable individual differences in cognition; (3) sensorimotor and effortful control skills as individual and interactive predictors of parent-reported autism characteristics (Social Responsiveness Scale) at 3 years, using multiple regression; and (4) moderation of interactions by familial likelihood. Sensorimotor skills were longitudinally associated with effortful control at the subsequent measurement point from 12-15 months. Socioeconomic status indicators did not predict stable between-infant differences in sensorimotor or effortful control skills. Effortful control skills were longitudinally related to 3-year autism characteristics from the first year of life, with evidence for an interaction with sensorimotor skills at 24 months. Effects of effortful control increased with age and were particularly important for infants with family histories of autism. Results are discussed in relation to different theoretical frameworks: Developmental Cascades and Anterior Modifiers in the Emergence of Neurodevelopmental Disorders. We suggest a role for 24-month effortful control in explaining the emergent autism phenotype. RESEARCH HIGHLIGHTS: Sensorimotor skills longitudinally predicted effortful control from 12-15 months onward but effortful control did not longitudinally predict sensorimotor skills during infancy. Measures of effortful control skills taken before the age of 1 predicted continuous variation in autism characteristics at 36 months, with associations increasing in strength with age. Effortful control (measured at 12-15 and 24 months) was a stronger predictor of 36-month autism characteristics in infants with elevated familial likelihood for autism. The relationship between 24-month sensorimotor skills and 36-month autism characteristics was stronger in infants with weaker effortful control skills.

Parent-mediated intervention in infants with an elevated likelihood for autism reduces dwell time during a gaze-following task.

Cognitive markers may in theory be more sensitive to the effects of intervention than overt behavioral measures. The current study tests the impact of the Intervention with the British Autism Study of Infant Siblings-Video Interaction for Promoting Positive Parenting (iBASIS-VIPP) on an eye-tracking measure of social attention: dwell time to the referred object in a gaze following task. The original two-site, two-arm, assessor-blinded randomized controlled trial (RCT) of this intervention to increase parental awareness, and responsiveness to their infant, was run with infants who have an elevated familial likelihood for autism (EL). Fifty-four EL infants (28 iBASIS-VIPP intervention, 26 no intervention) were enrolled, and the intervention took place between 9 months (baseline) and 15 months (endpoint), with gaze following behavior measured at 15 months. Secondary intention to treat (ITT) analysis showed that the intervention was associated with significantly reduced dwell time to the referent of another person's gaze (ß = -0.32, SE = 0.14, p = 0.03) at 15-month treatment endpoint. Given the established link between gaze following and language, the results are considered in the context of a previously reported, non-significant and transient trend toward lower language scores at the treatment endpoint (Green et al. (2015) The Lancet Psychiatry, 2(2), 133-140). Future intervention trials should aim to include experimental cognitive measures, alongside behavioral measures, to investigate mechanisms associated with intervention effects.

Mid-childhood autism sibling recurrence in infants with a family history of autism.

Autism sibling recurrence in prospective infant family history studies is ~20% at 3 years but systematic follow-up to mid-childhood is rare. In population and clinical cohorts autism is not recognized in some children until school-age or later. One hundred and fifty-nine infants with an older sibling with autism underwent research diagnostic assessments at 3 years and mid-childhood (6 to 12 years (mean 9)). We report the autism sibling recurrence rate in mid-childhood and compare developmental and behavioral profiles at mid-childhood and 3 years in those with earlier versus later recognized autism, and those who had, or had not, received a community autism diagnosis. The autism recurrence rate in this sample in mid-childhood was 37.1%, 95% CI [29.9%, 44.9%] and higher in boys than girls. Around half of those diagnosed with autism in mid-childhood had not received a diagnosis at 3 years. Later, diagnosis was more common in girls than boys. While some had sub-threshold symptoms at 3, in others late diagnosis followed a largely typical early presentation. Sibling recurrence based on community clinical diagnosis was 24.5%, 95% CI [18.4%, 31.9%]. Those who also had a community diagnosis tended to be older, have lower adaptive function and higher autism and inattention symptoms. Notwithstanding limitations of a single site study, modest sample size and limits to generalisability, autism sibling recurrence in family history infants may be higher in mid-childhood than in studies reporting diagnostic outcome at 3 years. Findings have implications for families and clinical services, and for prospective family history studies.

Familial Recurrence of Autism: Updates From the Baby Siblings Research Consortium.

OBJECTIVES: Autism spectrum disorder (ASD) is estimated to be ∼10 times higher in children with versus without an autistic sibling in population-based studies. Prospective studies of infant siblings have revealed even higher familial recurrence rates. In the current prospective longitudinal study, we provide updated estimates of familial ASD recurrence using a multinational database of infants with older autistic siblings. METHODS: Data were collated across 18 sites of the Baby Siblings Research Consortium, an international network studying the earliest manifestations of ASD. A total of 1605 infants with an older autistic sibling were followed from early in life to 3 years, when they were classified as ASD or non-ASD. Hierarchical generalized linear modeling, with site as a random effect, was used to examine predictors of recurrence in families and calculate likelihood ratios. RESULTS: A total of 20.2% of siblings developed ASD, which is not significantly higher than the previously reported rate of 18.7%. Male infant sex and >1 older affected sibling were significant predictors of familial recurrence. Proband sex also influenced recurrence rates, with siblings of female probands significantly more likely to develop ASD than siblings of male probands. Race and maternal education were also associated with recurrence in families. CONCLUSIONS: The familial recurrence rate of ASD, as measured in infant sibling studies, has not changed appreciably since previous estimates were made in 2011. Younger siblings of autistic children, particularly those who are male, have an affected female sibling, multiple affected siblings, or are impacted by social inequities, should be closely monitored and promptly referred for diagnostic evaluation.

Sex differences in social brain neural responses in autism: temporal profiles of configural face-processing within data-driven time windows.

Face-processing timing differences may underlie visual social attention differences between autistic and non-autistic people, and males and females. This study investigates the timing of the effects of neurotype and sex on face-processing, and their dependence on age. We analysed EEG data during upright and inverted photographs of faces from 492 participants from the Longitudinal European Autism Project (141 neurotypical males, 76 neurotypical females, 202 autistic males, 73 autistic females; age 6-30 years). We detected timings of sex/diagnosis effects on event-related potential amplitudes at the posterior-temporal channel P8 with Bootstrapped Cluster-based Permutation Analysis and conducted Growth Curve Analysis (GCA) to investigate the timecourse and dependence on age of neural signals. The periods of influence of neurotype and sex overlapped but differed in onset (respectively, 260 and 310 ms post-stimulus), with sex effects lasting longer. GCA revealed a smaller and later amplitude peak in autistic female children compared to non-autistic female children; this difference decreased in adolescence and was not significant in adulthood. No age-dependent neurotype difference was significant in males. These findings indicate that sex and neurotype influence longer latency face processing and implicates cognitive rather than perceptual processing. Sex may have more overarching effects than neurotype on configural face processing.

Parent-infant interaction trajectories in infants with an elevated likelihood for autism in relation to 3-year clinical outcome.

Developmental antecedents of autism may affect parent-infant interactions (PII), altering the context in which core social skills develop. While studies have identified differences in PII between infants with and without elevated likelihood (EL) for autism, samples have been small. Here, we examined whether previously reported differences are replicable. From a longitudinal study of 113 EL and 27 typical likelihood infants (TL), 6-min videotaped unstructured PII was blind rated at 8 and 14 months on eight interactional qualities. Autism outcome was assessed at 36 months. Linear mixed-effects models found higher parent sensitive responsiveness, nondirectiveness, and mutuality ratings in TL than EL infants with and without later autism. PII qualities at 8 (infant positive affect, parent directiveness) and 14 months (infant attentiveness to parent, mutuality) predicted 3-year autism. Attentiveness to parent decreased between 8 and 14 months in EL infants with later autism. This larger study supports previous findings of emerging alterations in PII in this group and extends on this by detecting earlier (8-month) predictive effects of PII for autism outcome and a more marked trajectory of decreased social attentiveness. The findings strengthen the evidence base to support the implementation of early preemptive interventions to support PII in infants with early autism signs.

Impact of and research priorities in early onset epilepsy: An investigation of parental concerns.

[Background and aim] Early onset epilepsy is a neurological condition with significant developmental consequences, and presents affected children and families with challenges which pervade many aspects of family life. Whilst the concerns of parents and the impact on quality of life is well documented in qualitative research, little emphasis has been placed on the context of 'early onset', and the implications of these concerns for research priority setting. We aimed to explore parental perspectives regarding concerns and the impact of early onset epilepsy on the child and family, and to identify priorities for future paediatric epilepsy research. [Methods] The Brain development in Early Epilepsy: Parent Priorities (BEE-PP) project employed a mixed methods approach to collect information on parents' experience of having a child diagnosed with early onset epilepsy before 36 months old and aged up to 16 years old. Parents completed an online survey (n = 15) followed by a focus group (n = 5) to explore their main concerns regarding early onset epilepsy, the impact on family life and research priorities. [Results] A thematic analysis of the focus group data generated eight themes related to concerns of parents, the impact on the family and research priorities. The three main concerns identified were the expected trajectory of their child's development, a lack of seizure control following diagnosis and adverse behavioural side effects of medication. Within family life, early onset epilepsy had an impact on sibling autonomy and psychosocial adaptation, poorer parental wellbeing and restricted social and personal activities. The need for clearer information regarding their child's developmental trajectory, and managing the side effects of medication and their interactions with behaviour over time were topics of priority for future epilepsy research. [Interpretation] The impact of early onset epilepsy on the family is pervasive and requires the provision of appropriate healthcare service-led support for families to improve quality of life and children's adjustment to epilepsy. Regular monitoring of the concerns of parents and the impact of the diagnosis would be beneficial for addressing epilepsy-related and psychosocial needs of the wider family throughout their child's development. Implications for future research priority setting with regards to improved clinician-to-parent information sharing and managing the behavioural side effects of medication are discussed.

Generalisation of Social Communication Skills by Autistic Children During Play-Based Assessments Across Home, School and an Unfamiliar Research Setting.

We investigated autistic children's generalisation of social communication over time across three settings during a play-based assessment with different adults and explore the potential moderating effects on generalisation of age, nonverbal IQ and level of restricted and repetitive behaviours. The social communication abilities of 248 autistic children (2-11 years, 21% female, 22% single parent, 60% white) from three UK sites were assessed from 1984 video interactions in three contexts with three different interaction partners (parent/home, teaching assistant/school, researcher/clinic) at baseline, midpoint (+ 7m) and endpoint (+ 12m) within the Paediatric Autism Communication Trial-Generalised (PACT-G), a parent-mediated social communication intervention. Children's midpoint social communication at home generalised to school at midpoint and to clinic at endpoint. Generalisation was stronger from home to school and clinic than school to home and clinic. Generalisation was not moderated by age, nonverbal IQ or restricted and repetitive behaviour. Broader child development did not explain the pattern of results. The current study is the largest study to date to explore generalisation with autistic children and provides novel insight into their generalisation of social communication skills. Further research is needed to gain a more comprehensive understanding of facilitators of generalisation across settings and interaction partners in order to develop targeted strategies for interventions to enhance outcomes for young autistic children.

Clinical, socio-demographic, and parental correlates of early autism traits in a community cohort of toddlers.

Identifying factors linked to autism traits in the general population may improve our understanding of the mechanisms underlying divergent neurodevelopment. In this study we assess whether factors increasing the likelihood of childhood autism are related to early autistic trait emergence, or if other exposures are more important. We used data from 536 toddlers from London (UK), collected at birth (gestational age at birth, sex, maternal body mass index, age, parental education, parental language, parental history of neurodevelopmental conditions) and at 18 months (parents cohabiting, measures of socio-economic deprivation, measures of maternal parenting style, and a measure of maternal depression). Autism traits were assessed using the Quantitative Checklist for Autism in Toddlers (Q-CHAT) at 18 months. A multivariable model explained 20% of Q-CHAT variance, with four individually significant variables (two measures of parenting style and two measures of socio-economic deprivation). In order to address variable collinearity we used principal component analysis, finding that a component which was positively correlated with Q-CHAT was also correlated to measures of parenting style and socio-economic deprivation. Our results show that parenting style and socio-economic deprivation correlate with the emergence of autism traits at age 18 months as measured with the Q-CHAT in a community sample.

Exploring the association between social camouflaging and self- versus caregiver-report discrepancies in anxiety and depressive symptoms in autistic and non-autistic socially anxious adolescents.

LAY ABSTRACT: Social camouflaging or masking refers to strategies autistic individuals adopt to hide their autism persona when trying to fit in. It is unclear whether camouflaging is only applicable to social differences unique to autism, or more generally to any types of social difference, such as experiences of mental health difficulties. We asked 43 autistic and 39 non-autistic adolescents (aged 14-19 years, all of whom showed similarly high levels of social anxiety) and their primary caregivers to complete questionnaires about their mental health (anxiety and depression) and autistic traits, and adolescents self-reported camouflaging behaviours. We wondered if camouflaging may be used to hide mental health difficulties reported by young people and affect caregiver report on symptom severity. We found that adolescents who self-reported greater levels of autistic traits, anxiety and depression symptoms compared with their caregivers reported greater camouflaging. Adolescents who agreed on having high levels of autistic traits and anxiety symptoms with their caregivers reported greater camouflaging behaviours. We discuss how having high levels of autistic traits and anxiety may increase adolescents' camouflaging behaviours to hide social differences, which may contribute towards poor mental health outcomes. We think it is important to talk with adolescents about how camouflaging social and mental health difference can have negative impacts for mental health as well as possible positive social gains.

The roles of sensory hyperreactivity and hyporeactivity in understanding infant fearfulness and emerging autistic traits.

BACKGROUND: Existing evidence indicates that atypical sensory reactivity is a core characteristic of autism, and has been linked to both anxiety (and its putative infant precursor of fearfulness) and repetitive behaviours. However, most work has used cross-sectional designs and not considered the differential roles of hyperreactivity and hyporeactivity to sensory inputs, and is thus limited in specificity. METHODS: 161 infants with and without an elevated likelihood of developing autism and attention-deficit hyperactivity disorder (ADHD) were followed from 10 to 36 months of age. Parents rated an infant precursor of later anxiety (fearfulness) using the Infant Behaviour Questionnaire at 10 and 14 months, and the Early Childhood Behavioural Questionnaire at 24 months, and sensory hyperreactivity and hyporeactivity at 10, 14 and 24 months using the Infant Toddler Sensory Profile. Domains of autistic traits (restrictive and repetitive behaviours; RRB, and social communication interaction, SCI) were assessed using the parent-rated Social Responsiveness Scale at 36 months. Cross-lagged models tested (a) paths between fearfulness and hyperreactivity at 10-24 months, and from fearfulness and hyperreactivity to later autism traits, (b) the specificity of hyperreactivity effects by including hyporeactivity as a correlated predictor. RESULTS: Hyperreactivity at 14 months was positively associated with fearfulness at 24 months, and hyperreactivity at 24 months was positively associated with SCI and RRB at 36 months. When hyporeactivity was included in the model, paths between hyperreactivity and fearfulness remained, but paths between hyperreactivity and autistic traits became nonsignificant. CONCLUSIONS: Our findings indicate that alterations in early sensory reactivity may increase the likelihood of showing fearfulness in infancy, and relate to later social interactions and repetitive behaviours, particularly in individuals with a family history of autism or ADHD.

Understanding the relationship between social camouflaging in autism and safety behaviours in social anxiety in autistic and non-autistic adolescents.

BACKGROUND: Social camouflaging (hereafter camouflaging) in autism includes factors such as masking and compensating for one's neurodevelopmental differences, and to assimilate or 'fit in' with non-autistic peers. Efforts to hide one's authentic self and autism traits (masking) resemble impression management (IM) in safety behaviours identified in Clark and Wells' (1995) cognitive model of social anxiety (SA). This study explores the relationship between camouflaging in autism and safety behaviours in SA among autistic and non-autistic adolescents. METHODS: One hundred fifteen adolescents (14-19 years) with (n = 61; 36 female) and without (n = 54; 37 female) a clinical diagnosis of autism matched on age and SA symptom severity were recruited from clinics, schools and online. Adolescents completed online measures including autism traits, SA symptoms, camouflaging behaviours, SA-related safety behaviours and SA-related negative cognitions. Partial and bivariate Pearson's correlations and structural equation modelling were used to understand the relationship between camouflaging, safety behaviours, autism traits and SA in both groups. Exploratory factor analysis assessed item-level factor cross-loadings between camouflaging and safety behaviours. RESULTS: Across both groups, masking and IM were significantly associated with SA symptom severity, not autism traits, via SA-related social cognitions. Exploratory factor analysis indicated construct overlap across masking, assimilation, IM and avoidance behaviours and identified factors analogous to self-focused attention, social avoidance and mental rehearsal identified in the Clark and Wells' (1995) model of SA. CONCLUSIONS: This is the first study using group-matched design to identify that masking (factor in social camouflaging) and IM both relate to SA in autistic and non-autistic adolescents. Assessment and formulation of construct overlap between masking and IM may inform psychoeducation and adaptation of SA treatment for autistic adolescents.

Early development and epilepsy in tuberous sclerosis complex: A prospective longitudinal study.

AIM: To characterize early changes in developmental ability, language, and adaptive behaviour in infants diagnosed with tuberous sclerosis complex (TSC), and determine whether clinical features of epilepsy influence this pathway. METHOD: Prospective, longitudinal data were collected within the Early Development in Tuberous Sclerosis (EDiTS) Study to track development of infants with TSC (n = 32) and typically developing infants (n = 33) between 3 and 24 months of age. Questionnaire and observational measures were used at up to seven timepoints to assess infants' adaptive behaviour, developmental ability, language, and epilepsy. RESULTS: A significant group by age interaction effect showed that infants with TSC had lower adaptive functioning at 18 to 24 months old (intercept = 88.12, slope estimate = -0.82, p < 0.001) and lower developmental ability scores from 10 months old (intercept = 83.33, slope estimate = -1.44, p < 0.001) compared to typically developing infants. Early epilepsy severity was a significant predictor of these emerging developmental (R2 = 0.35, p = 0.004, 95% confidence interval [CI] -0.08 to -0.01) and adaptive behaviour delays (R2 = 0.34, p = 0.004, 95% CI -0.05 to -0.01]). Lower vocabulary production (intercept = -1.25, slope = -0.12, p < 0.001) and comprehension scores (intercept = 2.39, slope estimate = -0.05, p < 0.001) in infants with TSC at 24 months old were not associated with epilepsy severity. INTERPRETATION: Divergence of developmental ability and adaptive functioning skills occur in infants with TSC from 10 and 18 months, respectively. Associations between early epilepsy severity and impaired development supports the importance of early intervention to reduce seizure severity.

Mediation of 6-year mid-childhood follow-up outcomes after pre-school social communication (PACT) therapy for autistic children: randomised controlled trial.

BACKGROUND: There are very few mechanistic studies of the long-term impact of psychosocial interventions in childhood. The parent-mediated Paediatric Autism Communication Therapy (PACT) RCT showed sustained effects on autistic child outcomes from pre-school to mid-childhood. We investigated the mechanism by which the PACT intervention achieved these effects. METHODS: Of 152 children randomised to receive PACT or treatment as usual between 2 and 5 years of age, 121 (79.6%) were followed 5-6 years after the endpoint at a mean age of 10.5 years. Assessors, blind to the intervention group, measured Autism Diagnostic Observation Scale Calibrated Severity Score (ADOS CSS) for child autistic behaviours and Teacher Vineland (TVABS) for adaptive behaviour in school. Hypothesised mediators were child communication initiations with caregivers in a standard play observation (Dyadic Communication Measure for Autism, DCMA). Hypothesised moderators of mediation were baseline child non-verbal age equivalent scores (AE), communication and symbolic development (CSBS) and 'insistence on sameness' (IS). Structural equation modelling was used in a repeated measures mediation design. RESULTS: Good model fits were obtained. The treatment effect on child dyadic initiation with the caregiver was sustained through the follow-up period. Increased child initiation at treatment midpoint mediated the majority (73%) of the treatment effect on follow-up ADOS CSS. A combination of partial mediation from midpoint child initiations and the direct effect of treatment also contributed to a near-significant total effect on follow-up TVABS. No moderation of this mediation was found for AE, CSBS or IS. CONCLUSIONS: Early sustained increase in an autistic child's communication initiation with their caregiver is largely responsible for the long-term effects from PACT therapy on autistic and adaptive behaviour outcomes. This supports the theoretical logic model of PACT therapy but also illuminates fundamental causal processes of social and adaptive development in autism over time: early social engagement in autism can be improved and this can have long-term generalised outcome effects.

Differences in Intrinsic Gray Matter Connectivity and Their Genomic Underpinnings in Autism Spectrum Disorder.

BACKGROUND: Autism is a heterogeneous neurodevelopmental condition accompanied by differences in brain connectivity. Structural connectivity in autism has mainly been investigated within the white matter. However, many genetic variants associated with autism highlight genes related to synaptogenesis and axonal guidance, thus also implicating differences in intrinsic (i.e., gray matter) connections in autism. Intrinsic connections may be assessed in vivo via so-called intrinsic global and local wiring costs. METHODS: Here, we examined intrinsic global and local wiring costs in the brain of 359 individuals with autism and 279 healthy control participants ages 6 to 30 years from the EU-AIMS LEAP (Longitudinal European Autism Project). FreeSurfer was used to derive surface mesh representations to compute the estimated length of connections required to wire the brain within the gray matter. Vertexwise between-group differences were assessed using a general linear model. A gene expression decoding analysis based on the Allen Human Brain Atlas was performed to link neuroanatomical differences to putative underpinnings. RESULTS: Group differences in global and local wiring costs were predominantly observed in medial and lateral prefrontal brain regions, in inferior temporal regions, and at the left temporoparietal junction. The resulting neuroanatomical patterns were enriched for genes that had been previously implicated in the etiology of autism at genetic and transcriptomic levels. CONCLUSIONS: Based on intrinsic gray matter connectivity, the current study investigated the complex neuroanatomy of autism and linked between-group differences to putative genomic and/or molecular mechanisms to parse the heterogeneity of autism and provide targets for future subgrouping approaches.

Three year outcomes in infants with a family history of autism and/or attention deficit hyperactivity disorder.

Background: Most research on early outcomes in infants with a family history (FH) of autism has focussed on categorically defined autism, although some have language and developmental delays. Less is known about outcomes in infants with a FH of attention deficit hyperactivity disorder (ADHD). Methods: Infants with and without a FH of autism and/or ADHD, due to a first-degree relative with either or both conditions, were recruited at 5 or 10 months. Three year outcomes were characterised using latent profile analysis (LPA) across measures of cognitive ability, adaptive functioning and autism, ADHD and anxiety traits (n = 131). We additionally ran an LPA using only autism and ADHD measures, and the broader LPA in an independent cohort (n = 139) and in both cohorts combined (n = 270). Results: A Low Developmental Level + High Behavioural Concerns class had elevated autism, ADHD and anxiety scores, low cognitive and adaptive function, and included all but one child with autism. A Low Developmental Level + Typical Behaviour class had average cognitive ability and typical behaviour but low adaptive function. A Typical Developmental Level + Some Behavioural Concerns class had average cognitive and adaptive function but slightly elevated behaviour scores. A High Developmental Level + Typical Behaviour class had above average cognitive ability and typical behaviour. All four LPAs identified classes characterised by combinations of either, or both, Low Development Level and elevated behaviour scores, as well as a typically developing class. No classes had elevated autism or ADHD traits in isolation. Conclusions: Some infants with a FH of autism or ADHD have atypical developmental and behavioural outcomes, but do not show strong autism or ADHD traits in isolation. The field needs to recalibrate aims and methods to embrace the broader transdiagnostic pattern of outcomes seen in these infants.

Screening for Attention Deficit Hyperactivity Disorder in Young Autistic Adults: The Diagnostic Accuracy of Three Commonly Used Questionnaires.

OBJECTIVE: Attention Deficit Hyperactivity Disorder (ADHD) is a common co-occurring condition in autistic individuals. ADHD is sometimes first recognised in young adulthood because ADHD symptoms may be misattributed to autism due to superficial overlap in presentation and diagnostic overshadowing. It should be investigated whether ADHD questionnaires are accurate in screening symptoms in young adults with autism. The current study examined this. METHODS: Participants were autistic young adults (N = 119) who took part in the Special Needs and Autism Project (SNAP), a population-based cohort. ADHD research diagnoses were obtained through the parent-informed Young Adult Psychiatric Assessment. Parents and young adults (self-report sample N = 71) completed ADHD questionnaires (Aberrant Behavior Checklist hyperactivity/non-compliance subscale, Conners Adult ADHD Rating Scales ADHD Index, and Strengths and Difficulties Questionnaire ADHD subscale). Receiver operating characteristic analyses were conducted to explore if the questionnaires discriminated ADHD cases from non-cases. To assess whether results varied by intellectual functioning, subgroup analyses were completed for those with an IQ ≥ 70 vs. <70. RESULTS: Weighted ADHD rates were high. Overall although the measures were performing at or close to adequate levels (area under the curve was 0.66 to 0.79 for parent-report and 0.70 to 0.65 for self-report), no single measure met adequate thresholds for sensitivity and specificity simultaneously. Tool performance was not different for those with an IQ ≥ 70 vs. <70. CONCLUSION: No single measure reported adequate performance for distinguishing ADHD from non-ADHD cases in this sample of young autistic adults. Use of current thresholds may lead to under-diagnosis.

Cortical responses to social stimuli in infants at elevated likelihood of ASD and/or ADHD: A prospective cross-condition fNIRS study.

Autism spectrum disorders (ASD) and attention-deficit hyperactivity disorder (ADHD) are highly prevalent neurodevelopmental conditions that often co-occur and present both common and distinct neurodevelopmental profiles. Studying the developmental pathways leading to the emergence of ASD and/or ADHD symptomatology is crucial in understanding neurodiversity and discovering the mechanisms that underpin it. This study used functional near-infrared spectroscopy (fNIRS) to investigate differences in cortical specialization to social stimuli between 4- to 6-month-old infants at typical and elevated likelihood of ASD and/or ADHD. Results showed that infants at both elevated likelihood of ASD and ADHD had reduced selectivity to vocal sounds in left middle and superior temporal gyrus. Furthermore, infants at elevated likelihood of ASD showed attenuated responses to visual social stimuli in several cortical regions compared to infants at typical likelihood. Individual brain responses to visual social stimuli were associated with later autism traits, but not ADHD traits. These outcomes support our previous observations showing atypical social brain responses in infants at elevated likelihood of ASD and align with later atypical brain responses to social stimuli observed in children and adults with ASD. These findings highlight the importance of characterizing antecedent biomarkers of atypicalities in processing socially relevant information that might contribute to both phenotypic overlap and divergence across ASD and ADHD conditions and their association with the later emergence of behavioural symptoms.

Mapping the link between socio-economic factors, autistic traits and mental health across different settings.

LAY ABSTRACT: Autistic individuals are more likely than non-autistic individuals to experience a mental health condition in their lifetime, and this includes externalising and internalising symptoms. We know very little about how different environments and family conditions impact these symptoms for autistic individuals. Improving our understanding of these relationships is important so that we can identify individuals who may be in greater need of support. In this article, we seek to improve our understanding of how environmental and family conditions impact externalising and internalising symptoms in autistic and non-autistic people. To do this, we conducted analyses with two cohorts in very different settings - in Europe and South Africa - to ensure our findings are globally representative. We used advanced statistical methods to establish environmental and family conditions that were similar to each other, and which could be combined into specific 'factors'. We found that four similar 'factors' could be identified in the two cohorts. These were distinguished by personal characteristics and environmental conditions of individuals, and were named Person Characteristics, Family System, Parental and Material Resources. Interestingly, just 'Family System' was associated with internalising and externalising symptoms, and this was the same in both cohorts. We also found that having high traits of autism impacted this relationship between Family System and mental health conditions with opposite directions in the two settings. These results show that characteristics in the Family System are associated with internalising and externalising symptoms, and autistic persons are particularly impacted, reinforcing the notion that family stressors are important to consider when implementing policy and practice related to improving the mental health of autistic people.