London: Does your toddler miss out on afternoon naps? Beware, it may make your kid more stressed, unhappy and also increase the risk of life-long mental health problems, a new US study has claimed.
Researchers at the University of Colorado Boulder found that young kids who miss just one daytime nap become more anxious and less interested in the world around them.
They are also less excited by happy events and found the slightest stressful event hard to cope with. This is because missing naps "taxes the way toddlers express different feelings", the researchers said.
And long-term sleep deprivation, they warned, could even lead to lifelong, mood-related problems, Daily Mail reported.
For the study, the team measured the sleep patterns of toddlers aged two to three years. The kids wore a special device which measured how much they slept, with their parents also keeping a sleep log.
The researchers filmed the kids' facial expressions as they completed two jigsaws on one day when they'd had their usual nap, and on another when they'd been deprived of it.
The results, published in the Journal of Sleep Research, showed that tired toddlers who successfully completed the first puzzle were 34 percent less positive in their emotional responses than when they'd been well-rested.
And on being given another deliberately unsolvable puzzle the team noticed that the tired toddlers were a third more stressed by it than when they'd enjoyed their usual nap.
Toddlers who had missed out on a nap were also more than a third (39 percent) less curious about the unsolvable puzzle than when they were well rested, said Prof LeBourgeois.
Prof LeBourgeois said: "A sleepy child in a classroom or nursery environment may not be able to engage with others and benefit from positive interactions."
"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. Just like good nutrition, adequate sleep is a basic need," she added.