Sleep difficulties and related behavioral problems in Korean preschool children.

<bold>Objectives: </bold>Sleep difficulties are associated with various behavioral problems and cognitive development, but the association has not been thoroughly evaluated in preschoolers with and without developmental disability (DD). The aim of this study was to compare the behavioral and cognitive characteristics of poor and good sleepers with and without DD in a community-based sample of preschool children.<bold>Methods: </bold>We recruited 196 children aged 34-77 months from community-based daycare centers, kindergartens, and special education centers. Children were classified as poor sleepers with DD (n = 23), poor sleepers without DD (n = 23), good sleepers with DD (n = 64), and good sleepers without DD (n = 94). Poor sleepers were defined based on Children's Sleep Habits Questionnaire Total Sleep Disturbance Score (CSHQ TSDS) cutoff of >52.<bold>Results: </bold>When compared to good sleepers with DD, poor sleepers with DD scored significantly higher on the Attention Problems (p = 0.005) and Aggressive Behaviors (p = 0.001) subscales of the CBCL, indicating greater difficulty. Caregivers of the poor sleepers with DD reported more depressive symptoms (p = 0.028) and more stress related to the child (p = 0.002) and the parent (p = 0.045) than caregivers of the good sleepers with DD. On the other hand, when compared to good sleepers without DD, poor sleepers without DD scored significantly higher only on the Anxious/Depressed subscale (p = 0.045) of the CBCL. Cognitive development and adaptive functioning were not significantly different between poor and good sleepers with and without DD. Among the subscales of the CSHQ, the Sleep Onset Delay showed strongest correlation with behavioral measures of the children and distress of the caregivers.<bold>Conclusion: </bold>Externalizing problems such as aggressive behaviors, rather than cognitive development, are associated with sleep difficulties in preschool children with DD. [ABSTRACT FROM AUTHOR]