First night effect analysis in a cohort of young children with autism spectrum disorder.

Study Objectives: To evaluate for the finight effect (FNE) in a group of young children with autism. Design: Analysis of polysomnographic data from a 2-night sleep laboratory study. Setting: Clinical Center of the National Institutes of Health. Patients or Participants: 15 children (aged 2-10 years) with a diagnosis of an ASD. Interventions: None. Measurements and Results: Polysomnographic analysis showed the presence of a FNE for wake after sleep onset minutes, stage 2, and sleep effi ciency, but not for REM sleep parameters or TST. Conclusions: In this 2-night polysomnographic analysis of sleep stages in young children with autism, we did not fi the expected second night increase in total sleep time or REM sleep percentage or a decrease in REM sleep latency. This lack of an FNE for TST and REM parameters suggests that a single-night polysomnogram may be suffi cient to evaluate