Sleep Modulates Daytime Behavior in Children with Autism Spectrum Disorders

Background: Sleep problems are highly prevalent in children with autism spectrum disorders (ASD) and contribute to problematic daytime behaviors. Studies employing objective measures of sleep in relation to parent report of sleep and daytime behavior have been limited.

Objectives: We hypothesized that parental sleep concerns in children with ASD, confirmed by objective measures of sleep, would modulate daytime behavior in specific, rather than global, dimensions.

Methods: Fifty eight children, ages 4–10 years, participated in this study. Forty-two had a clinical diagnosis of ASD confirmed by the Autism Diagnostic Observation Schedule, and were defined as ASD-PS (n = 27) or ASD-GS (n = 15) based on the Parental Concerns Questionnaire. Sixteen were typically developing (TD) and reported to be good sleepers. Behavior was measured by the Childhood Behavior Checklist (CBCL), Repetitive Behavior Scale (RBS), and Parental Concerns Questionnaire (PCQ). Sleep was measured with two nights of wrist actigraphy (Mini-Mitter AW64) and polysomnography (PSG); nights were averaged. Measurements obtained included total sleep time (TST), sleep latency (SL), sleep efficiency (SE), wake time after sleep onset (WASO), nighttime movement and fragmentation (MFI)-actigraphy only, and arousal index (AI)-PSG only. Kruskal-Wallis statistics were used to determine significance between all three groups, and Mann-Whitney U tests provided between group comparisons on the overall significant parameters with significance set at p < 0.05.

Results: On the RBS, the ASD-PS group showed significantly increased scores on the compulsive scale as compared to the ASD-GS group. On the PCQ, the ASD-PS group showed more hyperactivity than the ASD-GS group. Both the ASD-GS and ASD-PS groups differed significantly from the TD children globally on the CBCL, RBS, and PCQ, with the exception of the sleep item on the PCQ. The groups differed on objective measures of sleep. With actigraphy, the ASD-PS group differed significantly from the ASD-GS group on sleep latency [mean(SD)] [53.4(25.6) versus 23.0(19.0) minutes]; sleep efficiency [80.9(6.6) versus 88.3(5.1)%], and MFI [(12.5(3.4) versus 9.4(3.1)]. With PSG, the ASD-PS group differed significantly from the ASD-GS group on sleep latency [(54.0(41.7) versus 34.9(34.3)] minutes. The ASD-GS and TD children were comparable on sleep parameters, except that the TD children had a higher MFI [(14.0(3.3) versus (13.5(3.4)].

Conclusions: Our results suggest that poor sleep in children with ASD, as defined by objective parameters, selectively modulates compulsive behavior and hyperactivity, as measured by parent report. Defining the phenotype of sleep in ASD, and its relation to daytime behavior, provides the foundation for focused studies of pathophysiology and targeted interventions.