Parent-Reported Sleep Problems in Children with Comorbid Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder
Sleep problems are frequent and well documented in children with Autism Spectrum Disorder (ASD), children with Attention Deficit/Hyperactivity Disorder (ADHD) and children with anxiety. Anxiety is also highly prevalent in children with ASD and ADHD: Up to 84% of children with ASD report anxiety symptoms, and 25% of children with ADHD meet criteria for co-occurring anxiety disorders. Although the prevalence of sleep problems has been well documented within each pure diagnosis, limited work has examined sleep problems and anxiety levels in children presenting with comorbid ASD/ADHD.
The objectives of the current study were to: 1) determine which diagnostic factors are related to problematic sleep behaviors in children with comorbid ASD/ADHD; and 2) to assess the association between problematic sleep behaviors and functional impairment in this sample specific to academic performance, intellectual functioning, and executive functioning. We expected that 1) increased ASD, ADHD, and anxiety symptom severity would predict elevated levels of problematic sleep behaviors, and 2) that more severe problematic sleep behaviors would predict increased academic, cognitive, and executive functioning difficulties over and above ASD and ADHD diagnostic severity and anxiety symptom severity.
Participants were 85 children (M age = 9.29, SD = 1.79; range = 6.66 – 12.91; 64 boys) who met DSM-IV criteria for both autism and ADHD. Sleep, anxiety, intellectual functioning, academic achievement and executive functioning were assessed. Hierarchical linear regression analyses were completed to determine the relationship between anxiety symptom severity, ASD symptom severity, ADHD severity, and total problematic sleep behavior. Multivariate regressions examining the link between problematic sleep behaviors and functional outcomes (i.e., academic performance, intellectual functioning, executive functioning), using anxiety symptoms severity, ASD symptom severity and ADHD symptom severity as predictor variables were also completed.
Parent-reported child anxiety significantly predicted parent-report of their child having nightmares (R2change = 0.078, Fchange = 7.036, β = 0.253, p = .010), being overtired for no reason (R2change = 0.132, Fchange = 12.448, β = 0.347, p < .001), and their total problematic sleep behaviors score (R2change = 0.091, Fchange = 8.221, β = 0.226, p = .005). ASD and ADHD severity did not significantly predict any sleep behaviors. Parent report of sleeping more than other children significantly predicted increased verbal IQ (F = 5.345, p = .023), and better sentence comprehension (F = 5.708, p = .019) and math computation (F = 5.296, p = .052), with a trend towards significance for spelling (F = 3.732, p = .057) over and above ASD, ADHD, or anxiety symptomology.
Results suggest that anxiety is the most consistent predictor of problematic sleep behaviors in children with comorbid ASD/ADHD, and that increased sleep may be beneficial for children with comorbid ASD and ADHD. Further, our results indicate that anxiety symptoms play a significant role in problematic sleep behavior in children with ASD and ADHD. Clinically, these results imply children with ASD who present with problematic sleep behaviors should receive a comprehensive evaluation to identify specific problematic sleep behaviors and their potential relationship with anxiety.