Link between toddler sleep patterns and behaviour at 5

Toddlers who sleep less than 10 hours a night or wake frequently are more likely to have emotional and behavioural problems at the age of five, according to a study from the Norwegian Institute of Public Health.

"We were surprised that the risks were so strong and consistent. Our study suggests that there is an increased risk of developing problems even when other factors are taken into account. Experimental studies are needed to find the causes," says Borge Sivertsen, lead author and senior researcher at the Norwegian Institute of Public Health.

Main findings

Those who slept 10 hours per day or less, or woke 3 times or more during the night at 18 months old were more likely to have emotional or behavioural problems at 5 years of age.

Frequent waking in the night was most strongly associated with internalising problems such as anxiety and depression, whereas short sleep duration was associated with both internalising and externalising problems such as aggression.

About the study

The results come from the longitudinal Norwegian Mother and Child Cohort Study. Over 32 000 mothers from the cohort completed questionnaires at week 17 of pregnancy and when their child reached 18 months and 5 years. They rated their child's emotional and behavioural problems using a standard child behaviour checklist and reported how long the child slept in a 24-hour period. The researchers accounted for factors such as maternal age, education, duration of pregnancy, number of siblings and the child's weight and sex.

"Early sleep problems may play a significant role in subsequent emotional or behavioural issues but other factors like parental mental health or the child's temperament may also be important. More research is needed to see whether sleep programmes in early childhood can help to prevent the onset of problems later" concludes Sivertsen.