Examining the Relation Between Sleep Problems and Behavioural Challenges in Youth With Down Syndrome.

The study is cross-sectional, so it cannot show that sleep problems caused behaviour problems or that behaviour problems caused sleep problems. Participants were children eligible for behavioural clinical trials and had at least one behavioural or sleep concern, so findings may not apply to all children with Down syndrome. Children with both Down syndrome and autism were excluded, so the findings may not apply to that group. Specific sleep disorders and obstructive sleep apnoea treatment status were not controlled. Actigraphy measured sleep from movement and did not use polysomnography, so apnoeic episodes may not have been captured. Behaviour outcomes were limited to externalising and internalising scores, so thought problems, social difficulties and inattention may not be captured. The sample was 65 children, and macro-level analyses used 55 to 64 participants, so it may not generalise broadly. Some data were missing, including CBCL subscale scores for one participant and some SIB-R subscale scores for nine participants.

The authors declared no conflicts of interest. Funding was provided by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and Fondation Jérôme Lejeune.

Do not read the week-level association as proof that poor sleep causes behaviour problems. The design was cross-sectional, and nightly sleep measured by actigraphy did not predict next-day behaviour.