The immediate impact of a tired toddler may be (painfully) obvious, but new research sheds light on how sleep issues at a young age may affect children years later.
A longitudinal study published in JAMA Pediatrics showed that toddlers who slept less than 10 hours a night or woke at least three times during the night were more likely to show emotional and behavioral problems when they turned 5. The risk was higher for internalizing problems, like being emotionally reactive, anxious or depressed, than for externalizing problems, like attention deficit or aggression, the researchers found.
The researchers told Reuters they were surprised by the strength of the correlation, although they had expected to find some association. Because of the nature of the study, the researchers point out that they weren’t able to determine a direct cause and effect.
“While only an experimental study can determine causality, our study does suggest that there is an increased risk of developing such problems, also after accounting for a range of other possible factors,” lead author Borge Sivertsen of Uni Research Health and the Norwegian Institute of Public Health in Bergen told Reuters.
The researchers analyzed data from an ongoing Norwegian study involving 32,662 pairs of mothers and children. The data is based on questionnaires mothers were given at three points: at 17 weeks pregnant, when the child was 18 months old, and when the child turned 5. The researchers controlled for factors such as maternal age, duration of pregnancy and number of other children, as well as behavioral and emotional issues that the child might have started out with.
In an accompanying editorial, Michelle M. Garrison of Seattle Children’s Research Institute in Washington sympathizes with parents, calling it a “classic chicken and egg conundrum.”
“Although a cross-sectional study cannot demonstrate the causal sequence, many parents point out that it sometimes seems to flow in both directions, setting up a feedback whirlpool of despair,” she writes. “Inadequate sleep seems to beget tired meltdowns, which in turn delay sleep onset, potentially setting the child up for even more behavior problems the next day.”
The study was one of the first to look at sleep issues and their impact on behavior at such a young age, Garrison said, adding that sleep interventions are most effective during the toddler years.
Other recent research has shown the importance of nighttime sleep vs. daytime naps, suggesting that parents may be better off letting their toddler skip a nap in favor of quality sleep at night. However it’s addressed, the new study adds a layer of urgency to solving sleep issues as a society, with a growing body of research linking poor sleep to serious health problems such as obesity and diabetes, as well as memory loss, poorer academic performance, and higher rates of substance abuse.
“The need to improve early childhood sleep is not only a family issue or a clinical problem but may be critical from a public health perspective as well,” Garrison concludes.