Journal of Sleep Disorders & Therapy
Open Access

Abstract

Infant Sleep Duration is Related to Externalizing Behavior at the Age of 18 Months: Results from a Dutch Cohort Study

Ilona Quaak, Marijke de Cock, Michiel de Boer and Margot van de Bor

Background: Sleep is essential for children’s daytime functioning. Sleep problems have been related to several behavioral disorders. In the last few decades, growing attention has been given to externalizing problem behavior. Previous work has indicated that children and adolescents presenting externalizing problem behavior are at risk for an array of disorders in adulthood, including anxiety, disruptive behavior, mood problems and substance use. Several studies have shown that sleep problems may be related to externalizing problem behavior; research however is limited, especially among children younger than 18 months.

Methods: Data from the Dutch mother-child cohort LINC (Linking Maternal Nutrition to Child Health) were used. Sleep patterns were assessed by sleep diaries, which were filled out by the parents or caretaker when the child was three, six, nine, twelve and eighteen months old. Using the sleep diaries, sleep duration, nocturnal awakenings and early awakenings were calculated for each child at each time point. Externalizing behavior was assessed by using the scale ‘Externalizing behavior’ of the Child Behavior Checklist 1.5-5. Mixed model analyses were conducted to determine whether random intercepts and/or slopes had to be included in analyses regarding the development of the sleep variables over time (0-18 months). A random intercept and random slope was included for sleep duration and nocturnal awakenings, while for early awakenings only a random intercept was added. Subsequently, linear regression analyses were carried out to study the relationship between sleep characteristics over time with externalizing behavior as continuous, dependent variable. Family history, educational level, smoking, alcohol use and illicit drug use during pregnancy were checked for possible confounding effects. In total, data from 85 to 91 mother-child pairs were included, depending on the sleep variable.

Results: The intercept of sleep duration was found to be significantly related to externalizing scores on the CBCL (β=-2.35; CI=-4.31, -0.16; p=0.03). No other significant results were found.

Conclusion/discussion: We found that sleep duration was significantly related to externalizing behavior at 18 months. More specifically our results indicate that children who sleep less on average show more externalizing behavior. However, results should be interpreted with caution as the sample size was limited. Future studies should make use of longitudinal designs and larger sample sizes to confirm the relationship between sleep patterns and behavioral development over time.