Testing the social motivation theory of autism: the role of co-occurring anxiety.

BACKGROUND: The Social Motivation Theory proposes that social reward processing differences underlie autism. However, low social motivation has also been linked to higher anxiety. Given the co-occurrence between autism and anxiety, it is possible that anxiety drives the association between social motivation and autistic characteristics. This study tests the mechanisms underlying the association between social motivation and autistic traits. METHODS: Participants were 165 adolescents (71 male), aged 10-16 years, from the Mapping profiles of cognition, motivation and attention in childhood (C-MAPS) study, enriched for autistic traits (70 participants with an autism diagnosis, 37 male). Participants completed a battery of online experimental tasks, including a Choose-a-Movie social motivation task and social cognition measures (theory of mind; emotion recognition), alongside parent-reported child anxiety and autistic traits. RESULTS: Higher social motivation was significantly associated with lower autistic traits (ß = -.26, p < .001). Controlling for social cognition did not change the association between social motivation and autistic traits. Controlling for anxiety did significantly reduce the strength of the association (unstandardized coefficient change: p = .003), although social motivation remained associated with autistic traits (ß = -.16, p = .004). Post hoc analyses demonstrated differential sex-effects: The association between social motivation and autistic traits was significant only in the females (ß = -.38, p < .001), as was the attenuation by anxiety (unstandardized coefficient change: p < .001). CONCLUSIONS: The association between social motivation and autistic traits could be partially attributed to co-occurring anxiety. Sex-specific effects found in females may be due to environmental factors such as increased social demands in adolescent female relationships. Results are consistent with self-report by autistic individuals who do not identify as having reduced social motivation.

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.

Associations between emotion recognition and autistic and callous-unemotional traits: differential effects of cueing to the eyes.

BACKGROUND: Although autism and callous-unemotional (CU) traits are distinct conditions, both are associated with difficulties in emotion recognition. However, it is unknown whether the emotion recognition difficulties characteristic of autism and CU traits are driven by comparable underpinning mechanisms. METHODS: We tested whether cueing to the eyes improved emotion recognition in relation to autistic and CU traits in a heterogeneous sample of children enhanced for social, emotional and behavioural difficulties. Participants were 171 (n = 75 male) children aged 10-16 years with and without a diagnosis of autism (n = 99 autistic), who completed assessments of emotion recognition with and without cueing to the eyes. Parents completed the assessment of autistic and CU traits. RESULTS: Associations between autistic and CU traits and emotion recognition accuracy were dependent upon gaze cueing. CU traits were associated with an overall decrease in emotion recognition in the uncued condition, but better fear recognition when cued to the eyes. Conversely, autistic traits were associated with decreased emotion recognition in the cued condition only, and no interactions between autistic traits and emotion were found. CONCLUSIONS: The differential effect of cueing to the eyes in autistic and CU traits suggests different mechanisms underpin emotion recognition abilities. Results suggest interventions designed to promote looking to the eyes may be beneficial for children with CU traits, but not for children with autistic characteristics. Future developmental studies of autism and CU characteristics are required to better understand how different pathways lead to overlapping socio-cognitive profiles.

Longitudinal associations between early childhood irritability and adolescent depression symptoms in autistic children are mediated by peer relationships but not educational engagement.

In the general population, irritability is associated with later depression. Despite irritability being more prevalent in autistic children, the long-term sequelae are not well explored. We tested whether irritability in early childhood predicted depression symptoms in autistic adolescents, and whether associations could be explained by difficulties in peer relationships and lower educational engagement. Analyses tested the longitudinal associations between early childhood irritability (ages 3-5) and adolescent depression symptoms (age 14) in a prospective inception cohort of autistic children (N = 390), followed from early in development shortly after they received a clinical diagnosis. Mediators were measured in mid-childhood (age 10) by a combination of measures, from which latent factors for peer relationships and educational engagement were estimated. Results showed early childhood irritability was positively associated with adolescent depression symptoms, and this association remained when adjusting for baseline depression. A significant indirect pathway through peer relationships was found, which accounted for around 13% of the association between early childhood irritability and adolescent depression, suggesting peer problems may partially mediate the association between irritability and later depression. No mediation effects were found for education engagement. Results highlight the importance of early screening and intervention for co-occurring irritability and peer problems in young autistic children.

Neural mechanisms of language development in infancy.

Understanding the neural processes underpinning individual differences in early language development is of increasing interest, as it is known to vary in typical development and to be quite heterogeneous in neurodevelopmental conditions. However, few studies to date have tested whether early brain measures are indicative of the developmental trajectory of language, as opposed to language outcomes at specific ages. We combined recordings from two longitudinal studies, including typically developing infants without a family history of autism, and infants with increased likelihood of developing autism (infant-siblings) (N = 191). Electroencephalograms (EEG) were recorded at 6 months, and behavioral assessments at 6, 12, 18, 24 and 36 months of age. Using a growth curve model, we tested whether absolute EEG spectral power at 6 months was associated with concurrent language abilities, and developmental change in language between 6 and 36 months. We found evidence of an association between 6-month alpha-band power and concurrent, but not developmental change in, expressive language ability in both infant-siblings and control infants. The observed association between 6-month alpha-band power and 6-month expressive language was not moderated by group status, suggesting some continuity in neural mechanisms.

Associations between childhood autistic traits and adolescent eating disorder behaviours are partially mediated by fussy eating.

OBJECTIVE: Previous literature shows an increased risk for eating disorders in autistic individuals. This study tested whether fussy eating contributes to the association between childhood autistic traits and adolescent eating disorder behaviours. METHOD: Using data from the Avon Longitudinal Study of Parents and Children, we estimated the intercept and slope of parent-rated autistic traits and fussy eating between 7 and 14 years (N = 8982) and their association with self-reported eating disorder behaviours at age 14 years, including the indirect path from autistic traits to eating disorder behaviours via fussy eating. Analyses were adjusted for child sex, maternal age at delivery, maternal body mass index and maternal education. RESULTS: Analyses found a small indirect pathway from autistic traits intercept to eating disorder behaviours via fussy eating slope (b = 0.017, 95% CI = 0.002-0.032, p = 0.026), with higher levels of autistic traits at age 7 years being associated with a shallower decline in fussy eating, which in turn was associated with greater eating disorder behaviours. CONCLUSION: Findings point towards fussy eating as a potential link between childhood autistic traits and later disordered eating. Addressing fussy eating patterns before they become entrenched may decrease risk for eating disorders later in development.

Callous-unemotional traits in youth with autism spectrum disorder (ASD): replication of prevalence estimates and associations with gaze patterns when viewing fearful faces.

Research suggests an increased prevalence of callous-unemotional (CU) traits in children with autism spectrum disorder (ASD), and a similar impairment in fear recognition to that reported in non-ASD populations. However, past work has used measures not specifically designed to measure CU traits and has not examined whether decreased attention to the eyes reported in non-ASD populations is also present in individuals with ASD. The current paper uses a measure specifically designed to measure CU traits to estimate prevalence in a large community-based ASD sample. Parents of 189 adolescents with ASD completed questionnaires assessing CU traits, and emotional and behavioral problems. A subset of participants completed a novel emotion recognition task (n = 46). Accuracy, reaction time, total looking time, and number of fixations to the eyes and mouth were measured. Twenty-two percent of youth with ASD scored above a cut-off expected to identify the top 6% of CU scores. CU traits were associated with longer reaction times to identify fear and fewer fixations to the eyes relative to the mouth during the viewing of fearful faces. No associations were found with accuracy or total looking time. Results suggest the mechanisms that underpin CU traits may be similar between ASD and non-ASD populations.

Emotion Recognition Performance in Children with Callous Unemotional Traits is Modulated by Co-occurring Autistic Traits.

OBJECTIVE: Atypical emotion recognition (ER) is characteristic of children with high callous unemotional (CU) traits. The current study aims to 1) replicate studies showing ER difficulties for static faces in relation to high CU-traits; 2) test whether ER difficulties remain when more naturalistic dynamic stimuli are used; 3) test whether ER performance for dynamic stimuli is moderated by eye-gaze direction and 4) assess the impact of co-occurring autistic traits on the association between CU and ER. METHODS: Participants were 292 (152 male) 7-year-olds from the Wirral Child Health and Development Study (WCHADS). Children completed a static and dynamic ER eye-tracking task, and accuracy, reaction time and attention to the eyes were recorded. RESULTS: Higher parent-reported CU-traits were significantly associated with reduced ER for static expressions, with lower accuracy for angry and happy faces. No association was found for dynamic expressions. However, parent-reported autistic traits were associated with ER difficulties for both static and dynamic expressions, and after controlling for autistic traits, the association between CU-traits and ER for static expressions became non-significant. CU-traits and looking to the eyes were not associated in either paradigm. CONCLUSION: The finding that CU-traits and ER are associated for static but not naturalistic dynamic expressions may be because motion cues in the dynamic stimuli draw attention to emotion-relevant features such as eyes and mouth. Further, results suggest that ER difficulties in CU-traits may be due, in part, to co-occurring autistic traits. Future developmental studies are required to tease apart pathways toward the apparently overlapping cognitive phenotype.

Testing the specificity of executive functioning impairments in adolescents with ADHD, ODD/CD and ASD.

Current diagnostic systems conceptualise attention deficit hyperactivity disorder (ADHD), oppositional defiant/conduct disorder (ODD/CD) and autism spectrum disorder (ASD) as separate diagnoses. However, all three demonstrate executive functioning (EF) impairments. Whether these impairments are trans-diagnostic or disorder-specific remains relatively unexplored. Four groups of 10-16 year-olds [typically developing (TD; N = 43), individuals clinically diagnosed with ADHD (N = 21), ODD/CD (N = 26) and ASD (N = 41)] completed Go/NoGo and Switch tasks. Group differences were tested using analysis of co-variance (ANCOVA) including age, IQ, sex, conduct problems and ADHD symptoms as co-variates. Results indicated some disorder-specificity as only the ASD group demonstrated decreased probability of inhibition in the Go/NoGo task compared to all other groups. However, shared impairments were also found; all three diagnostic groups demonstrated increased reaction time variability (RTV) compared to the TD group, and both the ODD/CD and the ASD group demonstrated increased premature responses. When controlling for ADHD symptoms and conduct problems, group differences in RTV were no longer significant; however, the ASD group continued to demonstrate increased premature responses. No group differences were found in cognitive flexibility in the Switch task. A more varied response style was present across all clinical groups, although this appeared to be accounted for by sub-threshold ODD/CD and ADHD symptoms. Only the ASD group was impaired in response inhibition and premature responsiveness relative to TD adolescents. The findings suggest that some EF impairments typically associated with ADHD may also be found in individuals with ASD.

Callous-unemotional traits in adolescents with autism spectrum disorder.

BACKGROUND: People with callous-unemotional traits and also those with autism spectrum disorder (ASD) display sociocognitive difficulties. However, the frequency and neurocognitive correlates of callous-unemotional traits within individuals with ASD are unknown. AIMS: To determine the prevalence of callous-unemotional traits in individuals with ASD and test their association with behavioural and cognitive measures. METHOD: Parents of 92 adolescents with ASD completed the Antisocial Processes Screening Device (APSD) for callous-unemotional traits. Adolescents participated in tasks of emotion recognition, theory of mind and cognitive flexibility. RESULTS: In total 51% (n = 47) scored above a cut-off expected to identify the top 6% on the APSD. Of these 17% (n = 8) had concurrent conduct problems. Regression analyses found callous-unemotional traits were associated with specific impairment in fear recognition but not with theory of mind or cognitive flexibility. CONCLUSIONS: Adolescents with ASD show high rates of callous-unemotional traits but, unlike in the general population, these are not strongly associated with conduct problems. The relationship of callous-unemotional traits to impairments in fear recognition suggests similar affective difficulties as in individuals with callous-unemotional traits without ASD.

No association between alexithymia and emotion recognition or theory of mind in a sample of adolescents enhanced for autistic traits.

LAY ABSTRACT: Alexithymia is a sub-clinical condition characterised by difficulties identifying and describing one's own emotions, which is found in many, but not all autistic people. The alexithymia hypothesis suggests that certain aspects of socio-cognitive functioning typically attributed to autism, namely difficulties in emotion recognition, might be better explained by often co-occurring alexithymia. It is important to understand what is specific to autism and what is due to other co-occurring characteristics to develop appropriate support for autistic people. However, most research on this topic has been conducted in adults, which limits our knowledge about the relevance of this theory to younger autistic populations. This study tested whether difficulties in emotion recognition and theory of mind traditionally associated with autism might be better explained by alexithymia in a sample of adolescents with and without a diagnosis of autism. Results found that difficulties in emotion recognition and theory of mind were both associated with autistic traits, and this was not accounted for by individual differences in levels of alexithymia. This research suggests that more work is needed to understand the applicability of the alexithymia hypothesis in younger populations, but that at least in adolescents and when using parent-report measures, alexithymia may not account for emotion recognition or theory of mind difficulties associated with autistic traits.

Parent, Teacher and Observational Reports of Emotional and Behavioral Problems in Young Autistic Children.

Emotional and behavioral problems (EBPs) frequently occur in young autistic children. Discrepancies between parents and other informants are common but can lead to uncertainty in formulation, diagnosis and care planning. This study aimed to explore child and informant characteristics are associated with reported child EBPs across settings. Participants were 83 4-8-year-old autistic children and their parents and teachers in the Autism Spectrum Treatment and Resilience (ASTAR) study. Questionnaires of child EBPs were completed by parents and teachers, and self-reported parenting stress and wellbeing measures were obtained. An observation of parent-child/researcher-child interaction was also completed. Parents reported more EBPs than teachers and parent-teacher agreement was low, particularly for emotional problems. Greater parenting stress and being verbal was associated with more parent- but not teacher-reported EBPs. More observed behaviors that challenge were displayed by minimally verbal children. More parenting stress could be associated with the presence of more EBPs in the home; alternatively, parenting stress may confound reports. It is essential for assessments of EBPs in autistic children to take a multi-informant approach. Better understanding of the associations between informant characteristics and informant discrepancies of EBPs is needed.

Factors associated with mental health symptoms among UK autistic children and young people and their parents during the COVID-19 pandemic.

LAY ABSTRACT: What is already known about the topic: The COVID-19 pandemic and the associated restrictions impacted all of society. There is emerging evidence showing a range of impacts on autistic children and young people and their families. Further research that looks at how individuals coped during the pandemic while considering how they were doing before the pandemic is needed.What this paper adds: This article explores whether how well autistic youth were doing before the pandemic influenced how they coped during the pandemic. It also looked at how well their parents were doing during the pandemic and whether any pre-pandemic factors influenced how they coped. Samples of both primary-school-aged autistic children and autistic teenagers and their parents were surveyed to answer these questions. More engagement and enjoyment in education provision during the pandemic and getting outside more were linked with better child and parental mental health during the pandemic. More attention deficit hyperactivity disorder before the pandemic was linked with more attention deficit hyperactivity disorder and behavioural problems during the pandemic in primary-school-aged autistic children, and more emotional problems during the pandemic in autistic teenagers. Parents with more mental health problems during the pandemic had more mental health problems before the pandemic.Implications for practice, research or policy: Encouraging engagement and enjoyment in education and promoting physical exercise are key intervention targets. Ensuring access to attention deficit hyperactivity disorder medication and support is important, especially if this is managed jointly across school and home.

Effects of a Parenting Intervention for Emotional and Behavioral Problems in Young Autistic Children Under Conditions of Enhanced Uncertainty: Two-Year Follow-up of a Pilot Randomized Controlled Trial Cohort (ASTAR) During the United Kingdom COVID-19 Pandemic.

OBJECTIVE: Most young autistic children display emotional and behavioral problems (EBPs). There is evidence that behavioral parenting interventions (BPIs) reduce these. The COVID-19 pandemic and associated lockdowns can be seen as a natural experiment to test the longer-term effect of BPIs under conditions of increased uncertainty. METHOD: Opportunistic follow-up (n = 49) of a pilot randomized controlled trial (RCT) cohort (n = 62 autistic children aged 6-11 years; originally randomized to a 12-week group BPI [Predictive Parenting; n = 31] or an attention control [Psychoeducation; n = 31]) was conducted during COVID-19-related lockdowns. Measures of parent-reported child irritability and parenting stress were collected at 3 time points (baseline: mean age = 6.7 years; primary endpoint: mean age = 7.1 years, ∼5 months after randomization; and COVID-19 follow-up: mean age = 8.8 years, ∼2 years after randomization). We tested the magnitude of intervention effects using point estimates of differences in child irritability and parenting stress between arms at primary endpoint and COVID-19 follow-up, covarying for baseline scores. We used area under the curve (AUC) analyses to obtain overall estimates of the average intervention effect across all 3 timepoints. Semi-structured qualitative interviews were conducted with a subsample of parents (n = 18). RESULTS: A small but significant intervention effect was found from baseline to COVID-19 follow-up in favor of Predictive Parenting on parent-reported child irritability (d = -0.33, 95% CI = -0.65, -0.01) and parenting stress (d = -0.31, 95% CI = -0.59, -0.03). No overall mean intervention effect for these measures as estimated by the AUC analyses (which takes into account the nonsignificant effect at primary endpoint) was found. Interview feedback on the both interventions was positive, and parents reported using strategies from Predictive Parenting during COVID-19-related restrictions. CONCLUSION: This opportunistic follow-up study at a time of stress indicates the need for careful consideration of how and when to measure the effects of BPIs in autistic child populations. Future trials should consider both the most appropriate endpoint and in what context effects may be more likely to be seen. CLINICAL TRIAL REGISTRATION INFORMATION: Autism Spectrum Treatment and Resilience (ASTAR); https://www.isrctn.com; 91411078.

A prospective study of associations between early fearfulness and perceptual sensitivity and later restricted and repetitive behaviours in infants with typical and elevated likelihood of autism.

LAY ABSTRACT: Restricted interests and repetitive behaviours are central to the diagnosis of autism and can have profound effects on daily activities and quality of life. These challenges are also linked to other co-occurring conditions such as anxiety and sensory sensitivities. Here, we looked at whether early emerging signs of anxiety and sensory problems appear before symptoms of autism by studying infants with a family history of autism, as these infants are more likely to develop autism themselves. Studying infant siblings provides an opportunity for researchers to focus on early developmental markers of autism as these infants can be followed from birth. This study found that early infant signs of anxiety (e.g. fear/shyness) predicted later perceptual sensitivity, and those infants who scored higher on fear/shyness and sensitivity were more likely to experience more persistent repetitive behaviours, but also social and communication difficulties in toddlerhood. Early signs of anxiety and perceptual sensitivity may thus relate to both later social difficulties and repetitive behaviours. These findings support the importance of further research exploring the causal links between these domains in relation to autism, resulting in increased understanding of children who go onto develop autism in the future and guiding early interventions and supports.

Pathways to adaptive functioning in autism from early childhood to adolescence.

Adaptive functioning is lower in many autistic individuals to a greater extent than would be expected based on IQ. However, the clinical features associated with these difficulties are less well understood. This study examines longitudinal and contemporaneous associations of adaptive functioning in autistic youth across a wide ability range. Parent-reported autism symptoms, co-occurring emotional, behavioral and attention deficit hyperactivity disorder (ADHD) symptoms, and IQ were assessed in early childhood (M age 7 years; T1) and 6 years later in adolescence (M age 13 years; T2) in 179 autistic youth. Adaptive functioning was assessed at T2. Structural equation modeling estimated pathways to adaptive functioning from autism, and psychiatric symptoms at T1 and T2, testing whether associations were driven by continuity of behaviors from T1 to T2 or their contemporaneous effect at T2, or both, controlling for T1 IQ. Lower adaptive functioning at T2 was associated with higher T1 and T2 ADHD symptoms (ß = -0.14, and ß = -0.21) but not behavioral nor emotional symptoms at either timepoint. Lower adaptive functioning at T2 was also associated with lower T1 IQ (ß = 0.43) and higher social communication symptoms (ß = -0.37) at T2 but not T1, but the relationship with ADHD symptoms remained. Paths were not moderated by sex or IQ. Increased symptoms of ADHD, both in early childhood and contemporaneously, were associated with reduced adaptive functioning in adolescence. Co-occurring ADHD may be a modifiable risk factor for adaptive function impairments and should be routinely assessed and when present evidence-based treatments initiated which may benefit adaptive functioning outcomes. LAY SUMMARY: Adaptive functioning is lower in many autistic individuals to a greater extent than would be expected based on IQ. However, the clinical features associated with these difficulties are less well understood. In a community sample higher attention deficit/hyperactivity disorder (ADHD) symptoms, but not emotional or behavioral symptoms, in both early childhood and contemporaneously were associated with lower adaptive functioning in autistic adolescents. Co-occurring ADHD may be a modifiable risk factor for adaptive function difficulties in autism.

Homotypic and Heterotypic Continuity in Psychiatric Symptoms From Childhood to Adolescence in Autistic Youth.

OBJECTIVE: Despite the high prevalence of mental health difficulties in autistic youth, little is known about the patterns of developmental continuity and change in psychiatric symptoms between childhood and adolescence. Using a stratified community-derived sample of autistic youth (n = 101; 57 males, 44 females), within (homotypic) and between (heterotypic) domain associations between psychiatric symptoms in childhood to adolescence were tested as well as whether any continuities were moderated by sex, IQ, autism symptom severity, social economic status, or parental mental health. METHOD: Autistic youth were assessed for emotional, behavioral, and attention-deficit/hyperactivity disorder (ADHD) symptoms in childhood (age 4-9 years) and adolescence (age 13-17 years) using parental diagnostic interview. Unadjusted and adjusted (accounting for the co-occurrence of psychiatric symptoms in childhood) weighted models tested homotypic and heterotypic associations between symptoms in childhood and adolescence. Moderation of significant pathways was tested using multigroup analysis. RESULTS: Adolescent psychiatric symptoms all were predicted by symptoms of their childhood counterparts (emotional symptoms incidence rate ratio [IRR] = 1.06, 95% CI = 1.02-1.10, p < .01; behavioral symptoms IRR = 1.38, 95% CI = 1.21-1.59, p < .01; ADHD symptoms IRR = 1.11, 95% CI = 1.05-1.19, p < .01); the only heterotypic pathway that remained significant in adjusted analyses was from childhood emotional symptoms to adolescent ADHD symptoms (IRR = 1.04, 95% CI = 1.01-1.07, p = .02). Sex moderated the homotypic ADHD symptoms pathway; associations were significant in female participants only. Child IQ moderated the homotypic behavioral symptoms pathway; the association was stronger in youth with IQ <70. CONCLUSION: Results from this community-based sample suggest that psychiatric symptoms in autistic youth exhibit substantial developmental continuity and thus highlight the importance of early screening and intervention. Sex and IQ may be important factors to consider when predicting likelihood of stability of ADHD and behavioral symptoms.

Infant excitation/inhibition balance interacts with executive attention to predict autistic traits in childhood.

BACKGROUND: Autism is proposed to be characterised by an atypical balance of cortical excitation and inhibition (E/I). However, most studies have examined E/I alterations in older autistic individuals, meaning that findings could in part reflect homeostatic compensation. To assess the directionality of effects, it is necessary to examine alterations in E/I balance early in the lifespan before symptom emergence. Recent explanatory frameworks have argued that it is also necessary to consider how early risk features interact with later developing modifier factors to predict autism outcomes. METHOD: We indexed E/I balance in early infancy by extracting the aperiodic exponent of the slope of the electroencephalogram (EEG) power spectrum ('1/f'). To validate our index of E/I balance, we tested for differences in the aperiodic exponent in 10-month-old infants with (n = 22) and without (n = 27) neurofibromatosis type 1 (NF1), a condition thought to be characterised by alterations to cortical inhibition. We then tested for E/I alterations in a larger heterogeneous longitudinal cohort of infants with and without a family history of neurodevelopmental conditions (n = 150) who had been followed to early childhood. We tested the relevance of alterations in E/I balance and our proposed modifier, executive attention, by assessing whether associations between 10-month aperiodic slope and 36-month neurodevelopmental traits were moderated by 24-month executive attention. Analyses adjusted for age at EEG assessment, sex and number of EEG trials. RESULTS: Infants with NF1 were characterised by a higher aperiodic exponent, indicative of greater inhibition, supporting our infant measure of E/I. Longitudinal analyses showed a significant interaction between aperiodic slope and executive attention, such that higher aperiodic exponents predicted greater autistic traits in childhood, but only in infants who also had weaker executive functioning abilities. LIMITATIONS: The current study relied on parent report of infant executive functioning-type abilities; future work is required to replicate effects with objective measures of cognition. CONCLUSIONS: Results suggest alterations in E/I balance are on the developmental pathway to autism outcomes, and that higher executive functioning abilities may buffer the impact of early cortical atypicalities, consistent with proposals that stronger executive functioning abilities may modify the impact of a wide range of risk factors.

Exposure to family stressful life events in autistic children: Longitudinal associations with mental health and the moderating role of cognitive flexibility.

LAY ABSTRACT: Experiencing stressful life events, such as a parent having had serious illness, parental divorce, bullying and victimization, is known to increase risk for mental health difficulties in neurotypical children. However, few studies have looked at whether stressful life events have a similar impact in autistic youth and if any individual characteristics may moderate the impact of said life events. In this study, we tested whether in autistic children aged 7-11 years, exposure to family-level stressful life events predicted later mental health symptoms (and vice versa). We also tested whether associations between stressful life events and mental health symptoms differed depending on the child's level of cognitive flexibility. We found stressful life events only predicted internalizing symptoms (such as anxiety and depression) in children with clinically significant difficulties in cognitive flexibility (as rated by their parents). Mental health symptoms did not predict future exposure to stressful life events. Results suggest that information about exposure to stressful life events and cognitive inflexibility may be helpful in identifying autistic children who may be at risk of developing anxiety and depression symptoms.

Behavioural and physiological response to frustration in autistic youth: associations with irritability.

BACKGROUND: Irritability is a common and impairing occurrence in autistic youth, yet the underlying mechanisms are not well-known. In typically developing populations, differences in frustration response have been suggested as important driver of the behavioural symptoms of irritability. Research exploring the role of frustration response as a risk factor for irritability in autistic populations is limited and often uses parent report or observer ratings; objective measures of frustration response appropriate for use in autistic populations are required to advance the field. METHODS: In the current study, fifty-two autistic adolescents aged 13-17 years from a population-based longitudinal study completed an experimental task designed to induce frustration through exposure to periods of unexpected delay. Behavioural (number of button presses) and physiological (heart rate; HR) metrics were collected during delay periods. Irritability was measured using the parent-rated Affective Reactivity Index (ARI). Analyses used mixed-level models to test whether irritability was associated with different slopes of behavioural and physiological response to experimentally induced frustration during the task. Age and baseline HR (for the physiological data only) were included as covariates. RESULTS: Analyses showed a marginal association between irritability and the slope of behavioural response (incident rate ratio (IRR) =.98, p=.06), and a significant association with the slope of physiological response (b=-.10, p=.04); higher levels of irritability were associated with a dampened behavioural and physiological response, as indicated by flatter slopes of change over the course of the task. The pattern of results largely remained in sensitivity analyses, although the association with physiological response became non-significant when adjusting for IQ, autism symptom severity, and medication use (b=-.10, p=.10). CONCLUSIONS: Results suggest that the current experimental task may be a useful objective measure of frustration response for use with autistic populations, and that a non-adaptive response to frustration may be one biological mechanism underpinning irritability in autistic youth. This may represent an important target for future intervention studies.