By Traci Pedersen Associate News Editor Reviewed by John M. Grohol, Psy.D. on December 28, 2013

Putting toddlers to bed at a specified time may put them out of sync with their internal body clocks, making it difficult for them to fall asleep, according to a new University of Colorado Boulder study.

In a group of 14 toddlers, researchers pinpointed the time when the hormone melatonin spiked in the evening, indicating the start of the biological night. The findings showed that toddlers with later melatonin rise times took longer to fall asleep after being put to bed, said CU-Boulder Assistant Professor Monique LeBourgeois, Ph,D.

There is relatively little research out there on how the physiology of toddlers may contribute to the emergence of sleep problems, said study leader LeBourgeois.

Sleeping at the wrong biological clock time leads to sleep difficulties, like insomnia, in adults.

Although adults can choose when they go to sleep, toddlers rarely have this option, said LeBourgeois.

This study is the first to show that a poor fit between bedtimes selected by the parents of toddlers and the rise in their evening melatonin production increases their likelihood of nighttime settling difficulties, said LeBourgeois.

About 25 percent of young children have difficulty settling down after bedtime, said LeBourgeois. Problems may include having trouble falling asleep, bedtime resistance, tantrums, and episodes known as curtain calls, such as calling out from bed or coming out of the bedroom, often repeatedly, for another story, glass of water or bathroom trip, she said.

Toddlers with longer intervals between the onset of nightly melatonin release and their bedtimes were shown to fall asleep more quickly and had decreased bedtime resistance as reported by their parents, according to the study.

Sleep difficulties in early childhood are predictive of later emotional and behavioral problems, as well as poor cognitive function, that can persist into later childhood and adolescence.And parents of young children with sleep problems often report increased difficulties in their own sleep patterns, which can cause chronic fatigue and even marital discord, she said.

The rest is here:
Toddler Bedtime Should Coincide With Melatonin Increase