A rare experimental study of kids shows inadequate nighttime sleep alters several aspects of their emotional health — and in some surprising ways.

Study leader Dr. Candice Alfano, University of Houston professor of psychology and director of the Sleep and Anxiety Center of Houston, and her team studied 53 children ages 7-11 over more than a week.

The children completed an in-lab emotional assessment twice, once after a night of healthy sleep and again after two nights where their sleep was restricted by several hours.

“After sleep restriction, we observed changes in the way children experience, regulate and express their emotions,” Alfano said. “But, somewhat to our surprise, the most significant alterations were found in response to positive rather than negative emotional stimuli.”

Although plenty of correlational research links inadequate sleep with poor emotional health, experimental studies with children are few. Further, the impact of sleep loss is not uniform across individuals and pre‐existing anxiety might exacerbate the effects of poor sleep on children’s emotional functioning.

The new research is the first to use a format that objectively tracks changes in physical as well as mental parameters across individuals. Emotion regulation was tracked to observe the way children respond after sleep deprivation or in association with pre-existing anxiety symptoms.

In the study, a sample of 53 children, seven – eleven years old with a mean age of 9, and 56 percent female, completed multimodal, assessments in the laboratory when rested and after two nights of sleep restriction. The sleep restrictions were for seven and six hours in bed, respectively. University of Houston researchers studied the children for more than a week. The children completed an in-lab emotional assessment twice, once after a night of healthy sleep and again after two nights where their sleep was restricted by several hours.

Sleep was monitored with polysomnography and actigraphy. Subjective reports of affect and arousal, psychophysiological reactivity and regulation, and objective emotional expression were examined during two emotional processing tasks, including one where children were asked to suppress their emotional responses.

The multi-method assessment had children view a range of pictures and movie clips eliciting both positive and negative emotions while the researchers recorded how children responded on multiple levels.

In addition to subjective ratings of emotion, researchers collected respiratory sinus arrhythmias (a non-invasive index of cardiac-linked emotion regulation) and objective facial expressions.

Alfano points out the novelty of these data. “Studies based on subjective reports of emotion are critically important, but they don’t tell us much about the specific mechanisms through which insufficient sleep elevates children’s psychiatric risk.”

Alfano highlights the implications of her findings for understanding how poor sleep might “spill over” into children’s everyday social and emotional lives.

“The experience and expression of positive emotions are essential for children’s friendships, healthy social interactions and effective coping. Our findings might explain why children who sleep less on average have more peer-related problems,” she said.

Another important finding from the study is that the impact of sleep loss on emotion was not uniform across all children. Specifically, children with greater pre-existing anxiety symptoms showed the most dramatic alterations in emotional responding after sleep restriction.

According to Alfano, these results emphasize a potential need to assess and prioritize healthy sleep habits in emotionally vulnerable children.

The study appears in the Journal of Child Psychology and Psychiatry.

Source: University of Houston