A toddler’s missed naps could lead to more than just the short-term crabbiness familiar to parents of sleep-deprived tots. A lack of afternoon shut-eye could also increase the odds of emotional problems later in life, according to a new study on nap-deprivation in young children.
“Toddlers need naps,” said Monique LeBourgeois, director of the sleep and development laboratory at the University of Colorado at Boulder.
Lack of sleep disrupts their ability to build skills for managing emotions, she explained. That puts them at risk for lifelong mood-related problems such as anxiety and depression, LeBourgeois said, citing long-term studies.
The owner of an Alameda day care center knows firsthand the effect of missed naps on toddlers. Marva Lyons, owner of Marva’s Happy Town Family Child Care Center, has seen napless toddlers crankily make demands on an arriving parent, or become quiet all afternoon.
“We can tell what’s wrong,” Lyons said. She said she’ll ask the child, —‰’You didn’t get your afternoon nap, did you?’ “
Lyons noted that some parents don’t put their toddler down for an afternoon rest. “You need to tell them to take a nap,” she said. “And there will be some good time for you, too, to do something around the house.”
At the center, toddlers get a two-hour siesta.
And 15 to 20 percent of toddlers aren’t getting the requisite minimum of 10 hours of sleep at night, LeBourgeois said, making afternoon naps critical for them to meet their total sleep needs of 12 to 14 hours a day.
LeBourgeois and her colleagues tested the effect of nap deprivation on 2½- to 3-year-olds. The study, funded by the National Institute of Mental Health, will be published later this year in the Journal of Sleep Research.
“We know children who don’t regulate their emotions well are at high risk for mood problems later on,” she said. Their study showed that lack of sleep “is one key factor” influencing how well a child manages his or her emotions, LeBourgeois said.
The researchers looked for such facial expressions as joy, interest, excitement, sadness, anger, anxiety, disgust, shame and confusion in kids working with puzzles who missed their usual midday sleep.
Even skipping one day of nap time for these children led to heightened frustration while working on a challenging puzzle, with the napless children showing 31 percent more negative emotions than their rested counterparts.
But even solving an easy puzzle didn’t bring them as much happiness; the nap-deprived kids were one-third less likely to display positive emotions. In an important nuance, the toddlers who missed their daily nap also showed less confusion — by 39 percent — when working on the challenging puzzle.
Signs of confusion are actually healthy, LeBourgeois explained. “Confusion is not bad. It’s a complex emotion showing a child knows something does not add up.”
The researchers monitored facial expressions, because they are the truest way to gauge emotion in toddlers. “It’s kind of hard to ask a 2½-year-old, ‘How do you feel and how much do you feel it?’ ” LeBourgeois said.
Toddlers haven’t developed skills to inhibit emotion, she added. “You get what you see. It’s almost like the most pure form of measuring emotions in young kids.”
A number of large, long-term studies linked lack of sleep in early childhood to anxiety, depression and other mood-related disorders later in life, LeBourgeois said.
A 2009 article in the journal Pediatrics, for example, stated that childhood sleep problems increase the odds of “later (psychological) difficulties.” And a 2010 study pointing to prevention concluded that managing a child’s sleep problems, “may improve health, including emotional well-being, in adolescence and adulthood.”
The tricky part about naps for parents is that toddlers are entering an age where their sleep cycles will start fluctuating. As they leave toddlerhood, they’ll gradually fade out of the need for a daily nap.
“When they start this transition, things are in flux,” LeBourgeois said. So if an older toddler’s sleep cycle starts to change such that he or she is beginning to miss naps, then parents should increase nighttime sleep to ensure the child gets adequate rest. For ages 3 to 5, that’s 11 to 13 hours, according to the National Sleep Foundation.
“If naps are still part of (toddlers’) normal sleep rhythms, then they’re absolutely important,” said David Clamen, director of the UC San Francisco Sleep Disorders Center. “I think this study nicely shows that.”
Contact Suzanne Bohan at 510-262-2789. Follow her at Twitter.com/suzbohan.
