Associations of circadian factors with insomnia symptoms and emotional and behavioral problems among school-age children

Study Objectives: To examine the associations of circadian characteristics (ie, chronotype and social jetlag) with insomnia symptoms and emotional and behavioral problems among school-age children. Methods: A total of 620 primary school children (median(age) = 10.06, standard deviation =1.16, 58.7% boys) were recruited and assessed by a set of parent-report questionnaires, including Children's Sleep Habit Questionnaire for measuring sleep-wake patterns and insomnia symptoms (bedtime resistance, sleep onset delay, and night waking), Children's Chronotype Questionnaire for assessing the child's chronotype preference, and Strength and Difficulties Questionnaire for assessing emotional and behavioral problems. Linear regression models were applied to examine the associations of chronotype and social jetlag with insomnia symptoms and mental health outcomes, in which age, sex, family income, and average sleep duration were entered as covariates. Results: Evening chronotype was significantly associated with bedtime resistance and sleep onset delay, while social jetlag was not related to insomnia symptoms. Evening chronotype was also significantly associated with externalizing symptoms after controlling for potential confounders. Conclusions: Evening chronotype, but not social jetlag, was the risk factor for insomnia symptoms, and evening chronotype was further associated with increased behavioral problems in school-age children. Our findings underscored the roles of circadian factors in relation to sleep and mental health problems in this young population.