A child who has problems sleeping may be more likely to be more aggressive and bullying in school than children who don’t, according to new research. But the researchers couldn’t say whether it was the sleep problems that contributed to a greater likelihood of bullying behavior, or whether bullies are simply more prone to sleep difficulties.
“Our study was cross-sectional and cannot prove causality,” Louise O’Brien, PhD of the University of Michigan and her colleagues noted.
“But dose-response findings were consistent with the hypothesis that sleep-disordered breathing, and sleepiness in particular, could contribute to conduct problems in schoolchildren.”
As for a possible mechanism, the researchers pointed to previous reports linking sleepiness with impaired emotional regulation.
The findings “raise the possibility that addressing the underpinnings of childhood sleepiness may offer a largely untapped opportunity to reduce the common problem of aggressive behavior in schoolchildren.”
Bullying has potential negative consequences for both the aggressor and the victim.
Bullies are at risk for psychiatric problems, delinquency, substance abuse, antisocial behavior, violence, and criminal activity, whereas victims are at risk for damaged self-image, depression, and decreased quality of life, according to the researchers.
One possible contributing factor to aggressive behavior is sleep-disordered breathing, they noted.
To explore the issue, O’Brien and her colleagues looked at children in grades 2 and 5 in an urban Michigan public school district where 30 percent of children live in poverty.
Parents of 341 children completed screening assessments for conduct problems, bullying behavior, and sleep-disordered breathing. Teachers also provided assessments of conduct problems, behavior, and disciplinary problems in school.
The researchers found that 32 percent of the children were classified by a parent or teacher as having a conduct problem and 17 percent received at least two disciplinary referrals from teachers. Furthermore, 12 percent of the children in the study were classified as demonstrating bullying behavior.
About 23 percent of the children snored more than half the time — which is suggestive of sleep-disordered breathing. These children were also sleepier than those who did not habitually snore.
Children with conduct problems according to parent or teacher reports were significantly more likely than nonaggressive children to screen positive for sleep-disordered breathing (30 percent versus 14 percent).
Although they were also significantly more likely to snore habitually, it was a sleepiness subscale and not a snoring subscale (which is more specific to sleep-disordered breathing) that predicted conduct problems in a multivariate analysis.
“Although previous literature has reported aggressive behavior as a possible symptom of sleep-disordered breathing, we now suggest more broadly that common and frequently unrecognized daytime sleepiness, related perhaps in some but not all cases to sleep-disordered breathing, could underlie a sizable portion of aggressive behaviors within urban public schools,” O’Brien and her colleagues wrote.
Children classified as having bullying behavior according to their parents — but not when they were so classified by teachers — were more likely to have high sleep-disordered breathing risk (42 percent versus 17.5 percent), with increasingly severe bullying associated with higher scores on the sleep-related breathing disorder scale.
In addition, children with at least two discipline referrals in school were more likely to screen positive for sleep-disordered breathing, although the difference did not reach statistical or clinical significance.
Nevertheless, in a multivariate analysis, the sleep-related breathing disorders score did independently predict disruptive behavior in school.
The authors acknowledged some limitations, including possible selection bias stemming from the low recruitment rate, the use of a questionnaire to assess sleep-disordered breathing, and the inconsistency between parent and teacher reports of behavior.
The study appears in the latest issue of the journal Sleep Medicine.
Source: University of Michigan