(dailyRx News) Skipping a nap - even for one day - has a significant effect on toddlers' ability to express enthusiasm and deal with frustration according to a recent study.
While it may seem obvious that a nap-deprived child would be cranky, the skipped naps could contribute to long-term problems in emotional and cognitive development, warn researchers in the first known study to investigate how sleep deprivation affects young children's emotional states.
Monique LeBourgeois, an assistant professor at the University of Colorado Boulder, led the study, in which children's emotional reactions and facial expressions were assessed while they assembled puzzles and looked at photos on two different days, one with a nap and one without. They showed more anxiety and less interest on the day without a nap.
"Many young children today are not getting enough sleep, and for toddlers, daytime naps are one way of making sure their 'sleep tanks' are set to full each day," LeBourgeois said.
"This study shows insufficient sleep in the form of missing a nap taxes the way toddlers express different feelings, and, over time, may shape their developing emotional brains and put them at risk for lifelong, mood-related problems," she added.
The researchers analyzed the emotional expressions of healthy toddlers after the children had first followed a strict sleeping schedule that included 12.5 hours in bed for five straight days before the study.
Then, the children were asked to solve puzzles and were shown positive, negative or neutral images for their reactions on two different days: one day an hour after having skipped their normal 90-minute nap and then on a different day following their normal nap.
With less sleep, the toddlers had more negative expressions when shown neutral pictures and less positive expressions in response to the positive images.
Then they were videotaped while they worked on a solvable puzzle that had all its pieces and an unsolvable one with an incorrect piece that replaced a missing piece.
The researchers assessed the children's positive reactions when they correctly assembled the complete puzzle and their frustration when they could not finish the mismatched puzzle.
The toddlers had a 34 percent decrease in positive emotional responses on the day they finished the complete puzzles without a nap compared to the day when they had their regular nap.
As they tried to put together the insolvable puzzles, they showed a 31 percent increase in negative emotional responses when they were sleep-deprived compared to their well-rested attempts.
"Without a nap, children are not going to get an adequate amount of sleep for their developmental age," William Kohler, MD, director of the Florida Sleep Institute and director of Pediatric Sleep Services at Florida Hospital Tampa, told dailyRx. "It's yet another study showing us that quality sleep is essential for optimal cognitive development."
Kohler said the study used an instrument that is generally less accurate than a sleep study to assess the children's sleep time, so it could have overestimated or underestimated how much sleep they actually had. However, there is still a strong correlation between the accuracy of the instruments used here and standard sleep studies, he said.
"Unfortunately, parents don't always realize the importance of good sleep, so studies like this are important to educate parents of the need for the nap so that they make time available for the nap to take place," Kohler said.
He said most children can safely stop taking daily naps between the ages of 4 and 6. Until then, he said, regular, sufficient sleep is necessary to ensure children do not develop sleep disorders or experience delays in development.
The authors of this study also warned of the potential for future emotional problems if toddlers frequently have insufficient sleep.
"If insufficient sleep consistently ‘taxes’ young children’s emotion responses, they may not manage emotion regulation challenges effectively, potentially placing them at risk for future emotional/behavioral problems," the authors wrote.
The study, funded by the National Institute of Mental Health, appeared online and will be published in a future issue of Journal of Sleep Research. No information regarding financial disclosures was provided.