Later emotional and behavioral problems associated with sleep problems in toddlers: a longitudinal study.

IMPORTANCE Childhood sleep problems have been linked to a range of adverse health outcomes, but there is limited knowledge as to the temporal association between sleep problems and subsequent emotional and behavioral problems in young children. OBJECTIVE To examine whether sleep problems in toddlers aged 18 months are related to both concurrent and subsequent emotional and behavioral problems in preschool children aged 5 years. DESIGN, SETTING, AND PARTICIPANTS A large population-based longitudinal study was conducted in September 2014 using data from the Norwegian Mother and Child Cohort Study conducted at the Norwegian Institute of Public Health from June 1, 1999, to December 31, 2008. A total of 32 662 children or pregnancies were included. EXPOSURES Sleep was assessed by mother-reported child sleep duration and nocturnal awakenings. MAIN OUTCOMES AND MEASURES Emotional and behavioral problems were measured with items from the Child Behavior Checklist and operationalized according to recommended clinical cutoffs, corresponding to T scores of greater than 65 (93rd percentile). Risk ratios (RRs) were calculated using negative binomial regression, controlling for emotional and behavioral problems at 18 months and other relevant covariates. RESULTS Short sleep duration (<10 hours) in 556 children (1.7%) and frequent nocturnal awakenings (>= 3 times) in 1033 children (3.2%) at 18 months significantly predicted both concurrent and later incidence of emotional and behavioral problems at 5 years. The longitudinal RRs were generally larger for internalizing problems, with adjusted RRs of 1.59 (95% CI, 1.23-2.08) for both short sleep duration and 1.57 (95% CI, 1.28-1.93) for nocturnal awakenings; RRs for externalizing problems were 1.77 (95% CI, 1.37-2.30) and 1.25 (95% CI, 1.00-1.58), respectively. Additional adjustment for emotional and behavioral problems at 18 months slightly reduced the strength of these associations, and all RRs remained significant in the fully adjusted models. CONCLUSIONS AND RELEVANCE Early sleep problems predict later development of emotional and behavioral problems. Intervention studies are needed to examine whether sleep programs targeting early childhood may avert the onset of later adverse outcomes.