Children who are bullies or are aggressive or have conduct problems at school, are more likely to be sleepy during the day according to University of Michigan Medical School study.
The researchers looked at elementary school students in Michigan public schools who had been referred for conduct discipline problems or bullying and found that they had twice the rate of symptoms for sleep-disordered breathing, particularly daytime sleepiness among these students.
"What this study does is raise the possibility that poor sleep, from whatever cause, can indeed play into bullying or other aggressive behaviours – a major problem that many schools are trying to address," says Louise O'Brien, Ph.D., assistant professor in the university’s Sleep Disorders Centre and the departments of Neurology and Oral and Maxillofacial Surgery.
While schools may push the importance of healthy eating and exercise, “this study highlights that good sleep is just as essential to a healthy lifestyle," O’Brien said.
Causes of poor sleep
The study, published in Sleep Medicine, showed that sleepiness - which could be caused by disordered breathing problems like snoring or sleep apnoea, or other factors like fragmented sleep, over stimulation from electronic devices or chaotic home environments - seemed to be the biggest driver of the behaviour problems.
Although there are other reasons for these behaviours, if sleepiness does contribute to aggressive behaviour as this study suggests, a significant proportion of bullying in children might be eliminated by efforts to improve sleep quality and reduce daytime sleepiness, the researchers concluded.
Effect on the brain
"We know that the pre-frontal cortex area of the brain is sensitive to sleep deprivation, and this area is also related to emotional control, decision making and social behaviour," said O'Brien.
"So impairment in the prefrontal cortex may lead to aggression or disruptive behaviour, delinquency or even substance abuse.
“But the good news is that some of these behaviours can be improved. Sleep-disordered breathing can be treated, and schools or parents can encourage kids to get more sleep."
How much sleep is enough?
O'Brien recommends parents remove electronic devices from bedrooms, make getting enough sleep a priority and encourage children to sleep for the recommended amount of time without interruption.
Children in pre-school should sleep between 11-13 hours a night, and school-aged children between 10-11 hours.
Reference: Sleep Med (2011), doi:10,1016/j.sleep.2010.11.012