Sleep, executive functions, and repetitive behaviors in autism spectrum disorder: different patterns of association with lower- and higher-level repetitive behaviors

Abstract

Restricted and repetitive behaviors (RBs) are a core feature of autism spectrum disorder (ASD), although the mechanisms underlying different RB subtypes remain poorly understood. The present study investigated the differential contribution of executive functions (EFs) to lower- and higher-level RBs in autistic children and explored whether specific EF domains mediated the relationship between sleep disturbances and RBs. Fifty-seven autistic children aged 6–14 years underwent neuropsychological and behavioral assessment. RBs were assessed using the Repetitive Behavior Scale–Revised, executive functions using the Behavior Rating Inventory of Executive Function–2, sleep disturbances through the Sleep Disturbance Scale for Children, and behavioral difficulties through the Child Behavior Checklist. Partial correlations, regression analyses, and mediation models were performed. Distinct association patterns emerged across RB subtypes. Lower-level RBs were significantly associated only with emotional control difficulties, whereas higher-level RBs were associated with several EF domains, including inhibition, shifting, emotional control, planning, and initiation. Regression analyses showed that higher-level RBs were independently predicted by shifting difficulties, whereas lower-level RBs were significantly associated with IQ and behavioral problems. Mediation analyses indicated that emotional control difficulties significantly explained the association between sleep disturbances and lower-level RBs. In contrast, cognitive flexibility did not mediate the relationship between sleep disturbances and higher-level RBs. These findings provide preliminary evidence of different patterns of association across lower- and higher-level RBs in autistic children. Emotional regulation processes may be particularly relevant for lower-level RBs, whereas cognitive flexibility appears more strongly related to higher-level RBs. Findings also suggest that sleep disturbances may contribute to specific RB manifestations through different mechanisms.