Research Report: Bullying and Parasomnias: A Longitudinal Cohort Study
Monday, October 13, 2014
Researchers examine whether being bullied by peers can increase the risk of children developing parasomnias, or sleep disturbances.
Authors Dieter Wolke and Suzet Tanya Lereya, University of Warwick
Published by Pediatrics, September 2014
Past research has shown serious trauma and abuse, and other environmental factors, can lead to nightmares and night terrors. Researchers from the University of Warwick wanted to find out whether being bullied by peers, which can be very distressing for children, could increase the risk of developing parasomnias, or sleep disturbances: night terrors, sleepwalking and nightmares. Nightmares occur during rapid eye movement sleep, causing distress and are usually remembered. Night terrors, where children might fight imaginary monsters or scream, and sleepwalking, occur after sudden arousal from non-rapid eye movement sleep and are usually not remembered.
The researchers analysed data from 6,796 children who were interviewed at the ages of eight and 10 about their experiences of bullying. At 12 years old the same children were interviewed by trained psychology graduates about their experiences of parasomnias.
The study found that at the age of eight, 32.2 per cent of children were victims of bullying, one per cent were classed as bullies, and 6.7 per cent were both bullies and victims of bullying. By the age of 10, 18.5 per cent of the children were victims, 0.8 per cent were bullies and 5.5 per cent were bullies and victims. A total of 35.3 per cent of children were victims of bullying at either eight or 10, and 13.5 per cent were victims of bullying at both ages.
When it came to sleep disturbances, the research found that at an age of 12 years and nine months, 24.4 per cent of children said they had nightmares, 9.3 per cent had night terrors and 12.6 per cent reported sleepwalking. In total, 36.2 per cent had experienced at least one example of parasomnia in the last six months.
Analysis of the data, taking into account existing sleep problems and other traumatic experiences apart from bullying, showed a significant link between being bullied in primary school and suffering from parasomnia in early adolescence. The researchers found children who were bullied at age eight or 10 were more likely to have nightmares, night terrors, or sleepwalking at the age of 12, and those who had reported bullying at both ages were particularly vulnerable. The group most likely to suffer from any parasomnias were those who were both bullied themselves and bullied others. Those who bullied others but were not bullied themselves were the least likely to suffer any parasomnias.
Other factors increasing the risk of suffering from nightmares, night terrors and sleepwalking at the age of 12 were being female, having persistent sleep problems, and emotional and behavioural problems in childhood.
The researchers say the stress caused by being bullied could be the reason why victims suffer from nightmares. Stress can result in a change in chemicals produced by the body, leading to disturbed sleep and possibly nightmares. Increased anxiety can also lead to nightmares.
Implications for practice
The researchers suggest that if a child is experiencing frequent parasomnias, parents, teachers, school counsellors, and clinicians could consider asking about bullying. This would identify bullied children earlier and provide the help they need to reduce the negative effects of being bullied.
Impact of Bullying in Childhood on Adult Health, Wealth, Crime, and Social Outcomes, Dieter Wolke, William E Copeland, Adrian Angold, E Jane Costello, Psychological Science, August 2013. A previous work from the co-author of Bullying and Parasomnias, which shows serious illness, struggling to hold down a regular job, and poor social relationships are just some of the adverse outcomes in adulthood faced by those exposed to bullying in childhood.
Bullied Children and Psychosomatic Problems: A Meta-analysis, Gianluca Gini and Tiziana Pozzoli, Pediatrics, September 2013. A review of 30 existing studies which found a link between bullying and psychosomatic problems - physical ailments that are caused or made worse by mental factors. It concludes bullying should be considered a significant international public health problem.
Worse Than Sticks and Stones? Bullying is Associated with Altered HPA Axis Functioning and Poorer Health, JM Knack, LA Jensen-Campbell, A Baum, Brain and Cognition, November 2011. A study which measured levels of the hormone cortisol in adolescents exposed to stressful situations.