17862
Understanding Trajectories of Diurnal Rhythm of Cortisol in Children with Autism Based on Psychological and Behavioral Profiles
Individuals with autism spectrum disorders (ASD) are characterized by marked impairments in social interaction and communication, stereotypic repetitive behaviors, and difficulties responding to changes throughout the day. Furthermore, children with ASD also present significant heterogeneity in their profiles of stress responsivity. Previous studies investigating diurnal rhythm of cortisol have shown notable variability and dysregulation of cortisol throughout the day in children with ASD compared to typically developing (TYP) children. Moreover, findings suggest that sensory sensitivity may be a moderator of reactivity to daily stress, though few studies provide a comprehensive analysis of diurnal cortisol in children with ASDs.
Objectives:
The goal of this study was to replicate and extend previous findings in a new cohort of children to achieve a more detailed understanding of the heterogeneity of diurnal cortisol profiles of children with and without ASD. First, this study aimed to assess the stability of the diurnal cortisol profile in ASD and TYP children, and then sought to clarify the between- and within-group differences through consideration of time-of-day differences, behavioral, and psychological factors as potential covariates of cortisol regulation.
Methods:
The study sample consisted of 64 unmedicated, prepubertal children between 7 and 12 years old, 36 with ASD and 28 typically developing children. Salivary cortisol was collected for three diurnal cycles, consisting of four samples per day (T1: waking, T2: 30-minutes post-waking, T3: afternoon, T4: 30-minutes before bedtime), for a total of 12 samples per child. All participants also completed a battery of neuropsychological tests, including measures of intelligence (IQ) and parent-report measures of sensory sensitivity, stress sensitivity, and adaptability to change. Data were analyzed using a piecewise linear mixed effects model with the cortisol awakening response (T2-T1) separated out from the linear decline of cortisol levels from the awakening response until the end of the day (T2 to T4).
Results:
Preliminary results indicate that the two groups differ in steepness of the linear decline from T2 (30-minutes post-waking) to T4 (30-minutes before bedtime), with individuals with ASD having a flattened slope compared to the TYP group and elevated evening cortisol. Furthermore, there is a dampening effect of peak cortisol and linear decline in the ASD group from Day 1 to Day 3. In this sample, age, IQ, and sex do not significantly affect diurnal cortisol trajectories. However, scores on sensory and stress sensitivity, time of awakening, and adaptability to change throughout the day (and their interactive effects) are still to be explored to help elucidate between- and within-group differences of diurnal rhythm.
Conclusions:
The findings support a growing body of literature emphasizing the identification of specific subgroups of children with ASD, such as those with increased sensory sensitivity, and how cortisol regulation is moderated in terms of differential individual profiles. The findings support a complex interplay between physiological and behavioral stress and sensory sensitivity.