Objective: To compare the stability of the sleep-wake system of children with attention-deficit/hyperactivity disorder (ADHD) and controls by objective and subjective measures.
Method: Thirty-eight school-age boys with diagnosed ADHD and 64 control school-age boys were examined using actigraphic monitoring and sleep diaries, over 5 consecutive nights.
Results: Increased instability in sleep onset, sleep duration, and true sleep were found in the ADHD group compared with the control group. Discriminant analysis revealed that children's classification (ADHD versus control) could be significantly predicted on the basis of their sleep measures.
Conclusions: The findings support the hypothesis that instability of the sleep-wake system is a characteristic of children with ADHD. Given the potential negative effects of disturbed or unstable sleep on daytime functioning, it is recommended that a thorough sleep assessment be conducted when a sleep disturbance is suspected or when symptoms associated with daytime sleepiness or decreased arousal level are present.