Sleep-related breathing disorder is associated with hyperactivity in preschoolers.

INTRODUCTION Sleep problems are a prominent feature in children with attention deficit hyperactivity disorder (ADHD). Unlike existing studies that focused on extreme samples (i.e. normal vs. ADHD), our study investigated the associations of sleep-related behaviours and ADHD features in nonclinical Chinese preschoolers. METHODS All participants were recruited via advertisements and screened for eligibility through a telephone interview prior to an onsite visit. The maternal reports of the Conners' Parent Rating Scale (CPRS) and Pediatric Sleep Questionnaire (PSQ) were acquired from 110 Chinese preschoolers aged six years. Regression models were used to examine the association between CPRS and PSQ scores. RESULTS The results obtained from regression models on the CPRS and PSQ scores of the 110 participants showed that none of the sleep-related behavioural measures (i.e. sleep-related breathing disorder [SRBD], snoring, daytime sleepiness, restless legs syndrome) was associated with inattention in our sample. However, worse SRBD was associated with higher hyperactivity. CONCLUSION Our study underpins the importance of understanding the relationship between sleep-related behaviours and ADHD characteristics before the usual age of clinical diagnosis in children with ADHD.