Objective: A prominent noncore symptom of autistic disorder is disturbed sleep, but relatively few studies have investigated this symptom.
Method: A multimethod approach assessed the quantity and quality of sleep in 194 children (68 with autism [AUT], 57 with developmental delay without autism [DD], 69 with typical development) recorded over 1 week. Parent perceptions, structured questionnaires, and actigraphy were compared. In addition, problem sleep as defined by parents was compared with research diagnostic criteria for behavioral insomnia obtained from actigraph recordings.
Results: On actigraphy, children in the DD group, after sleep onset, exhibited more and longer awakenings than the other two groups. In contrast, children in the AUT group exhibited less total sleep time in 24 hours than the other two groups. Parent reports of sleep problems were higher in the AUT and DD groups than the typical development group, but parent reports did not concur with more objective RDC for behavioral insomnia. Parent reports of sleep problems in all of the groups were significantly associated with increased self-reports of stress. Total 24-hour sleep durations for all of the groups were shorter than recommended for preschool-age children.
Conclusions: Our study provides objective evidence that sleep patterns are different in preschool children across the categories of AUT, DD, or typical development.