Objectives/background: Correlational studies show that short sleep is associated with negative daytime outcomes in school-aged children, but there are few experimental sleep manipulation studies to assess whether this is a causal relation. The aim of this study was to determine the impact of mild, cumulative sleep restriction on daytime functioning of typically developing (TD) children and children with attention-deficit/hyperactivity disorder (ADHD).
Participants: A total of 36 school-aged children (n = 18 TD; n = 18 ADHD), aged 6-11 years participated.
Methods: Children participated in two sleep conditions (order counter-balanced). The Restricted condition required a 1 h reduction of time in bed for one week, and the Controlled Typical condition was based on participant's average baseline sleep. At the end of each condition, participants attended the sleep lab for overnight polysomnography and daytime functioning assessments.
Results: Children successfully reduced time in bed by ~1 h. Due to compensatory changes, total sleep time (TST) was reduced by only ~20 min, as children fell asleep faster and spent less time awake after sleep onset during the Restricted compared to Controlled Typical condition. Many daytime functions were not affected by this very mild sleep restriction, however, both groups showed significant changes in performance on an objective attention task and on a parent-rated emotional lability measure after six nights of minimal reductions in TST. There were no significant differences between groups.
Conclusions: Results suggest that a very mild sleep restriction can affect children's attention and emotional regulation, even with evidence of compensatory sleep mechanisms.