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

Autism is diagnosed based on social and communication difficulties, restricted and repetitive behaviours and sensory anomalies. Existing evidence indicates that anxiety and atypical sensory features are associated with restricted and repetitive behaviours, but cannot clarify the order of emergence of these traits. This study uses data from a prospective longitudinal study of infants with and without a family history of autism ( N = 247; Elevated Likelihood N = 170 and Typical Likelihood N = 77). Longitudinal cross-lag models tested bidirectional pathways between parent-rated infant fear/shyness and perceptual sensitivity at 8, 14 and 24 months, and associations between these domains and parent-rated restricted and repetitive behaviours and social communication scores at 36 months. In addition to within-domain continuity, higher levels of fear/shyness at 14 months were associated with higher levels of perceptual sensitivity at 24 months. Higher levels of both fear/shyness and perceptual sensitivity at 24 months were associated with greater restricted and repetitive behaviours and social communication scores at 36 months. Results demonstrate the directionality of developmental pathways between fear/shyness and perceptual sensitivity in infancy and toddlerhood, but question theories that argue that these domains specifically underlie restricted and repetitive behaviours rather than autism. Identifying how early emerging anxiety and sensory behaviours relate to later autism is important for understanding pathways and developing targeted support for autistic children. 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.

Exploring the impact of adolescent cognitive inflexibility on emotional and behavioural problems experienced by autistic adults

Autistic young people experience high levels of co-occurring mental health difficulties, including anxiety, depression and behavioural difficulties, across their lifespan. Understanding the neuropsychological mechanisms which underlie these difficulties is vital in developing personalised supports and interventions. Cognitive inflexibility is one candidate mechanism which is associated with co-occurring mental health comorbidities but is also associated with other features of autism such as restricted and repetitive behaviours. This study investigates the distinct longitudinal association between cognitive inflexibility, measured using objective neuropsychological measures and emotional and behavioural problems across adolescence and early adulthood. Eighty-one autistic people from a population-based longitudinal study were assessed at 16 and 23 years on measures of emotional and behavioural problems, with cognitive inflexibility, restricted and repetitive behaviours and verbal intelligence quotient measured at 16 years. We used structural equation modelling to investigate the relationship between cognitive inflexibility and emotional and behavioural symptoms at both timepoints while accounting for the severity of restricted and repetitive behaviours and verbal intelligence quotient. Our results indicate an effect of cognitive inflexibility on increased behavioural problems at 16 years and emotional problems across timepoints, which is distinct from restricted and repetitive behaviours and verbal intelligence quotient. Exploratory mediation analyses suggest that cognitive inflexibility may be one mechanism through which emotional difficulties are maintained longitudinally. Lay abstract Autistic people experience high levels of co-occurring mental health difficulties. To develop more effective treatments, a greater understanding of the thinking processes that may lead to these difficulties is needed. Cognitive inflexibility, defined as a rigid pattern of thoughts and subsequently behaviours, is one possible thinking trait which has previously been associated with both co-occurring mental health difficulties but also other features of autism such as restricted and repetitive behaviours. Restricted and repetitive behaviours include repetitive movements, ritualistic behaviours, and/or highly focused interests. This study investigates the relationship between, cognitive inflexibility, measured using neuropsychological tasks, and emotional and behavioural problems across adolescence and early adulthood. Eighty-one autistic people who were recruited to be representative of the wider autism population were assessed at 16 and 23 years on measures of emotional and behavioural problems, with cognitive inflexibility, restricted and repetitive behaviours and verbal intelligence measured at 16 years. We used statistical modelling to investigate the relationship between cognitive inflexibility and emotional and behavioural symptoms at both timepoints while accounting for the possible relationship with restricted and repetitive behaviours and verbal intelligence quotient. Our results suggest that cognitive inflexibility may be an important factor associated with emotional difficulties across adolescence and early adulthood. This suggests that developing intervention approaches targeting cognitive inflexibility may be an important step in improving the mental health of those with autism.

A Clinical and Cost Effectiveness Trial of A Parent Group Intervention To Manage Challenging Restricted and Repetitive Behaviours In Young Children With Autism Spectrum Disorder: Study Protocol For a Randomized Controlled Trial.

Background: Restricted and repetitive behaviours vary greatly across the autism spectrum, and although not all are problematic some can cause distress and interfere with learning and social opportunities. We have, alongside parents, developed a parent group based intervention for families of young children with autism, which aims to offer support to parents and carers; helping them to recognise, understand and learn how to respond to their child’s challenging restricted repetitive behaviours.Methods: The study is a clinical and cost effectiveness, multi-site randomised controlled trial of the Managing Repetitive Behaviours (MRB) parent group intervention versus a psychoeducation parent group Learning about Autism (LAA) (n=250; 125 intervention/125 psychoeducation; ~83/site) for parents of young children aged 3-9 years 11 months with a diagnosis of autism. All analyses will be done under intention-to-treat principle. The primary outcome at 24 weeks will use Generalised Estimating Equation (GEE) to compare proportion of children with improved RRB between the MRB group and the LAA group. The GEE model will account for the clustering of children by parent groups using exchangeable working correlation. All secondary outcomes will be analysed in a similar way using appropriate distribution and link function.The economic evaluation will be conducted from the perspective of both NHS costs, and family access to local community services. A ‘within trial’ cost-effectiveness analysis with results reported as the incremental cost per additional child achieving at least the target improvement in CGI-I scale at 24 weeks.DiscussionThis is an efficacy trial to investigate the clinical and cost effectiveness of a parent group based intervention designed to help parents understand and manage their child’s challenging RRB. If found to be effective this intervention has the potential to improve the well-being of children and their families, reduce parental stress, greatly enhance community participation and potential for learning, and improve longer-term outcomes.Trial Registration: Trial ID: ISRCTN15550611 Date registered: 07/08/2018URL: https://doi.org/10.1186/ISRCTN15550611

Dissecting the phenotypic heterogeneity in sensory features in Autism Spectrum Disorder: a factor mixture modelling approach

Background: Heterogeneity in the phenotypic presentation of Autism Spectrum Disorder (ASD) is apparent in the profile and the severity of sensory features. Here we applied Factor Mixture Modelling (FMM) to test a multidimensional factor model of sensory processing in ASD. We aimed to identify homogeneous sensory subgroups in ASD that differ intrinsically in their severity along continuous factor scores. We also investigated sensory subgroups in relation to clinical variables: sex, age, IQ, social communication symptoms, restricted and repetitive behaviours, adaptive functioning and symptoms of anxiety and Attention-Deficit/Hyperactivity Disorder.Methods: 332 children and adults with ASD between the ages of 6 and 30 years with IQs varying between 40 and 148 were included. First, three different confirmatory factor models were fit to the 38 items of the Short Sensory Profile (SSP). Then, latent class models (with two-to-six subgroups) were evaluated. The best performing factor model, the 7-factor structure, was subsequently used in two FMMs that varied in the number of subgroups: a two-subgroup, seven-factor model and a three-subgroup, seven-factor model.Results: The ‘three-subgroup/seven-factor’ FMM was superior to all other models based on different fit criteria. Identified subgroups differed in sensory severity from severe, moderate to low. Accounting for the potential confounding effects of age and IQ, participants in these sensory subgroups had different levels of social-communicative symptoms, restricted and repetitive behaviours, adaptive functioning skills and symptoms of inattention and anxiety.Limitations: Results were derived using a single parent-report measure of sensory features, the SSP, which limits the generalisability of findings.Conclusion: Sensory features can be best described by three homogeneous sensory subgroups that differ in sensory severity gradients along seven continuous factor scores. Identified sensory subgroups were further differentiated by the severity of core and co-occurring symptoms, and level of adaptive functioning, providing novel evidence on the associated clinical correlates of sensory subgroups. These sensory subgroups provide a platform to further interrogate the neurobiological and genetic correlates of altered sensory processing in ASD.

Dissecting the phenotypic heterogeneity in sensory features in Autism Spectrum Disorder: a factor mixture modelling approach

Background Heterogeneity in the phenotypic presentation of Autism Spectrum Disorder (ASD) is apparent in the profile and the severity of sensory symptoms. Here we applied Factor Mixture Modelling (FMM) to test a multidimensional factor model of sensory processing in ASD. We aimed to identify homogeneous sensory subgroups in ASD that differ intrinsically in their severity along continuous factor scores. We also investigated sensory subgroups in relation to clinical variables: sex, age, IQ, social communication symptoms, restricted and repetitive behaviours, adaptive functioning and symptoms of anxiety and Attention-Deficit/Hyperactivity Disorder. Methods 332 children and adults with ASD between the ages of 6 and 30 years with IQs varying between 40 and 148 were included. First, three different confirmatory factor models were fit to the 38 items of the Short Sensory Profile. Then, latent class models (with two-to-five subgroups) were evaluated. The best performing factor model, the 7-factor structure, was subsequently used in two FMMs that varied in the number of subgroups: a two-subgroup, seven-factor model and a three-subgroup, seven-factor model. Results The ‘three-subgroup/seven-factor’ FMM was superior to all other models based on different fit criteria. Identified subgroups differed in sensory severity from severe, moderate to low. Accounting for the potential confounding effects of age and IQ, participants in these sensory subgroups had different levels of social-communicative symptoms, restricted and repetitive behaviours, adaptive functioning skills and symptoms of inattention and anxiety. Limitations Results were derived using a single parent-report measure of sensory symptoms, the SSP, which has some notable construct limitations that constrain the generalisability of findings. Conclusion Sensory features can be best described by three homogeneous sensory subgroups that differ in sensory severity gradients along seven continuous factor scores. Identified sensory subgroups were further differentiated by the severity of core and co-occurring symptoms, and level of adaptive functioning, providing novel evidence on the associated clinical correlates of sensory subgroups. These sensory subgroups provide a platform to further interrogate the neurobiological and genetic correlates of altered sensory processing in ASD.

Management and treatment of autism spectrum disorders

Autism spectrum disorder (ASD) is a chronic disorder beginning early in development and comprising lifelong impairments in social communication and restricted and repetitive behaviours and interests. The manifestations of these core symptoms frequently vary across individuals, especially with differences in intellectual ability, and may change with age. In addition, people with ASD have high rates of co-occurring psychiatric disorders, including attention-deficit/hyperactivity disorder, anxiety and depression, tics/Tourette’s syndrome, and sleep problems. They frequently exhibit behaviours that challenge others, including aggression, self-injury, and high levels of irritability. Hence, their treatment and management requires a comprehensive approach to core and co-occurring symptoms. Management should include evidence-based approaches from health and also ASD-specific support from education, employment, social care, and the wider community. There is insufficient evidence to guide best practice, and more research on interventions is urgently required.