A child who soothes themselves back to sleep from an early age adjusts to school more easily than those who don’t, research from Queensland University of Technology (QUT) has found.

The Australian study revealed one in three children have escalating problems sleeping across birth to 5 years, which increased their risk of emotional and behavioral issues at school and put them at risk of attention deficit disorders.

Kate Williams, PhD, from QUT’s Faculty of Education, School of Early Childhood, says the research involved 2,880 children from the landmark study, Growing up in Australia: The Longitudinal Study of Australian Children (LSAC).

She analyzed the sleep behavior of children born in 2004 until they reached 6 to-7 years. “We now know 70% of children are regulating their own sleep by 5 years but for the remaining third it may be detrimental to them developmentally over time,” Williams says in a release. “The overwhelming finding is it’s vital to get children’s sleep behaviors right by the time they turn 5.”

Williams’ research titled “Early childhood profiles of sleep problems and self-regulation predict later school adjustment” was published in the British Journal of Educational Psychology.

Williams says her research was one of the first to use a large sample size and examine the long-term impact of children’s sleep on early school behavior. She says mothers reported on children’s sleep problems, emotional and attention from birth to 5 years, and teachers reported on children’s social emotional adjustment to school.

Williams says she was surprised by the high number of children identified as having escalating behavioral sleep problems across birth to 5 years, which was linked with poorer self-regulation of attention and emotion.

She says children characterized as having escalating sleep problems in early childhood were associated with higher teacher-reported hyperactivity, poorer classroom self-regulation, and emotional outbursts. “If these sleep issues aren’t resolved by the time children are 5 years old then they are at risk of poorer adjustment to school,” she says.

With more than 85% of families using child care or preschool services, Williams says there was an opportunity for better awareness about sleep hygiene practices before children started school. “Parents can withdraw some habits, like lying with children over and over, letting them into their bed, it’s really important to give children a sense of skill so they can do these things themselves,” she says. Williams also says sleep intervention strategies were extremely effective.

The study builds on QUT research which linked mandatory day time naps in child care centers to sleep problems later on.

“Sleep problems can be sorted out long before a child reaches school age provided parents, carers and child care works are aware and supported,” she says. “Prevention is the key.”