Children who are bullied at ages 8-10 are more likely to suffer from sleep walking, night terrors or nightmares by the time they are 12 years old.
In a study published this week in Pediatrics, journal of the American Pediatric Association, Professor Dieter Wolke and Dr Suzet Tanya Lereya from the University of Warwick, found being bullied increases the risk for a category of sleep disorders known as parasomnias. These are sleep-related problems such as nightmares, night terrors or sleep walking.
A cohort of children from the Avon Longitudinal Study of Parents and Children (ALSPAC) were interviewed at elementary school age (8 and 10 years) about bullying experiences and then about parasomnias at secondary school age (12-13 years).
Professor Wolke, from Warwick Medical School and the Department of Psychology, said: "We found children who were bullied at age 8 or 10 years were more likely to have nightmares, night terrors, or sleepwalking at age 12 years. Moreover, those who were bullied and bullied others (bully/victims) were most likely to have any parasomnia.
"Consistent with previous studies, being a female, having persistent sleep problems, and emotional and behaviour problems in childhood additionally increased the risk for parasomnias at age 12 years."
Dr Lereya, from the Department of Psychology, added that stress could be an important mechanism for the association between being bullied and parasomnias.
"Nightmares may occur when anxiety exceeds a threshold level and several studies have suggested that trait anxiety may be related to the frequency of parasomnias. However, even after controlling for pre-existing anxiety problems our results showed that being bullied may increase the risk for parasomnias."
The authors suggest that: "If a child is experiencing frequent parasomnias, parents, teachers, school counsellors, and clinicians may consider asking about bullying. This would allow detecting bullied children and providing the help they need at an early time to reduce the negative effects of being bullied."
Notes to editors
The study, 'Bullying and Parasomnias: A Longitudinal Cohort Study', Dieter Wolke, Suzet Tanya Lereya, is published in Pediatrics, http://pediatrics.
To speak to Professor Wolke, contact him on 07824358737, to speak to Suzet Tanya Lereya, contact her on 07964236156
Alternatively please contact Kelly Parkes-Harrison, Senior Press and Communications Manager, University of Warwick, firstname.lastname@example.org, 02476 150868, 07824 540863.