Sensory reactivity differences are a diagnostic criterion of autism. Sensory hyperreactivity has been linked to intolerance of uncertainty and anxiety in autistic children. However, research is yet to explore the mediating relationships or sensory hyporeactivity, seeking and anxiety subtypes in preschool-age autistic children. Therefore, we aimed to elucidate the relationships between sensory reactivity, intolerance of uncertainty and anxiety subtypes in a heterogeneous group of 54 preschool-age autistic children, age 3–5 years, using observation and parent-report assessments. Correlational analysis found sensory hyperreactivity, intolerance of uncertainty and total anxiety were significantly intercorrelated. In addition, sensory hyperreactivity was significantly correlated with separation anxiety when controlling for autism traits. Serial mediation analyses indicated significant full mediation between sensory hyperreactivity and anxiety through intolerance of uncertainty, and significant full mediation between sensory hyperreactivity and intolerance of uncertainty through anxiety. Our results suggest that sensory hyperreactivity is a key early factor in the development of anxiety, and supports that intolerance of uncertainty is an important interrelated construct in the development and maintenance of anxiety in autism. Our findings have important implications for the development of effective interventions. However, due to limitations with the measures, our research also highlights a pressing need for objective assessments of anxiety and intolerance of uncertainty that can be used with preschool-age autistic children. Lay abstract This study found links between greater sensory hyperreactivity (e.g., over-sensitive to sensory input), intolerance of uncertainty and anxiety, including separation anxiety, in autistic pre-schoolers. Sensory hyperreactivity may predict both anxiety and intolerance of uncertainty, and anxiety and intolerance of uncertainty may both be mutually important, mediating factors. These findings have implications for early anxiety interventions. But there is a pressing need for objective assessments that can be used with preschool-age autistic children.

There is growing evidence for an association between sensory reactivity and mental health in autism. This study set out to explore the relationship between sensory reactivity and mental health in preschool‐aged autistic children. In total 54 preschool‐aged children with an Autism Spectrum Condition took part. Sensory and mental health symptoms were obtained from the Sensory Processing Scale Inventory, Sensory Assessment of Neurodevelopmental Differences and the Behavioral Assessment System for Children–3. Correlational analyses showed a relationship between sensory reactivity and mental health symptoms in autistic preschool‐aged children. Results also indicate divergence in sensory‐mental health profiles between autistic preschool‐aged children who are verbal and those who use few to no words. For the first time this study has revealed a relationship between sensory hyper‐reactivity, as well as sensory seeking, and mental health symptoms outside of anxiety in autism. Of note, this relationship between sensory hyper‐reactivity and internalizing symptoms appears to be driven by those with few to no words. This has implications for both research and clinical interventions, in particular for our understanding of the factors underlying mental health symptoms in different autistic phenotypes, as well as the possible role of functional communication in mitigating the development of mental health symptoms. Lay Summary The present study found that in autistic preschoolers, externalizing mental health symptoms, such as hyperactivity, are related to sensory seeking (seeking out or being fascinated with sensory stimuli), and internalizing mental health symptoms, such as depression, are related to sensory hyper‐reactivity (sensitivity to sensory stimuli). Our results also show that whilst the relationships between externalizing symptoms and sensory seeking is seen across participants, the relationship between internalizing symptoms and sensory hyper‐reactivity was only seen in autistic preschoolers who used few to no words. This has important implications for the assessment of sensory differences as part of more rigorous mental health assessments, especially in autistic people who use few to no words.

Depression and sensory reactivity are both common in autism. However, there is little understanding of the predictive relationship between these factors, or the nature of this relationship in autistic children who speak few to no words. This study set out to explore the longitudinal relationship between sensory reactivity and depressive symptoms in 33 young autistic children who speak few to no words. We found positive correlations between depressive symptoms and hyper-reactivity and sensory seeking at both timepoints, and across timepoints. We further found a bidirectional predictive relationship between depressive symptoms and sensory seeking. These results implicate sensory seeking in the development of depressive symptoms in young autistic children who use few to no words. Our findings have important implications for preventative mental health interventions, especially for those with a developmental language delay.

Sensory reactivity differences are a diagnostic criterion in autism spectrum conditions. Sensory hyperreactivity has been linked to intolerance of uncertainty (IU) and anxiety in autistic children. However, research is yet to explore the mediating relationships or sensory hyporeactivity, seeking, and anxiety subtypes in preschool-age autistic children. Therefore, we aimed to elucidate the relationships between sensory reactivity, IU and anxiety subtypes in a heterogeneous group of 54 preschool-age autistic children, age 3-6 years, using a range of observational and parent-report assessments. Correlational analysis found sensory hyperreactivity, IU and anxiety subtypes, including generalised anxiety, social anxiety, obsessive-compulsive symptoms, physical injury fears, and separation anxiety, were significantly intercorrelated. Neither sensory hyporeactivity or seeking were significantly related to IU or anxiety subtypes. Serial mediation analyses indicated significant full mediation between sensory hyperreactivity and anxiety through IU, and significant full mediation between sensory hyperreactivity and IU through anxiety in preschool-age autistic children.Our results therefore suggest that theoretical models of anxiety in autism should consider sensory hyperreactivity as a predictive factor for anxiety, and supports that IU is an important interrelated construct in the development and maintenance of anxiety. Our findings have important implications for understanding anxiety and related symptoms in autistic children, which can inform the development of effective interventions. However, due to limitations with the measures, our research also highlights a pressing need for objective assessments of anxiety and IU that can be used with preschool-age autistic children.

Children with neurodevelopmental conditions (NDC) often have sensory reactivity differences, such as being overwhelmed by sounds, which can elicit distress in their everyday life. Furthermore, children with an NDC often present with a greater frequency of mental health symptoms compared to their typically developing peers. However little research has examined the relationship of these sensory reactivity differences on broader mental health. This study set out to explore the relationship between sensory reactivity and mental health symptoms. Data from parent-reported measures of sensory reactivity and mental health symptoms were collected for 49 children presenting with a neurodevelopmental condition and 42 typically developing (TD) controls. Partial correlational analyses, controlling for IQ, were used to elucidate the relationship between sensory reactivity and mental health symptoms. Children with an NDC were significantly more likely to present with a sensory reactivity difference or mental health symptom. Sensory seeking was found to be the sensory subtype most related to mental health symptoms, especially in externalising conditions. There was evidence also found for a relationship between depression, sensory seeking and sensory hypo-reactivity, and GAD and hyper-reactivity. Findings suggest a relationship between sensory reactivity and mental health symptoms in children with a neurodevelopmental condition. There is also preliminary evidence of unique sensory-based profiles of mental health. Assessment of sensory difficulties as part of more rigorous mental health assessments within mental health services will support more accurate diagnoses and intervention.