Printer friendly version
New evidence shows link between childhood trauma and psychotic experiences
10 July 2013
Royal College of Surgeons in Ireland (RCSI)
Researchers at the Royal College of Surgeons in Ireland (RCSI) have demonstrated that
exposure to childhood trauma (physical assault and bullying) is linked to
psychotic experiences, (such as hearing voices), and in turn the cessation of
traumatic experiences led to a significant reduction in the incidence of
psychotic experiences. The findings are being presented today at the European
Society for Child & Adolescent Psychiatry Congress taking place in Dublin
and appear in this month’s edition of the American Journal of Psychiatry.
This was a collaborative project between the National Suicide Research Foundation (Cork)
and RCSI with funding from the Health Research Board (HRB) and the European
Union Framework 7 Programme. The researchers undertook a nationally
representative prospective cohort study of 1,112 school-based adolescents aged
13-16 years, and assessed them at baseline, three-months and 12-months for
childhood trauma (defined as physical assault and bullying) and psychotic experiences.
ProfessorMary Cannon, HRB Clinician Scientist and Senior Investigator, Department of
Psychiatry, RCSI said “Our findings are the first to show there is direct
evidence between exposure to childhood trauma and psychotic experience.
Furthermore, it showed that the cessation of traumatic experiences was
associated with a significant reduction in the incidence of psychotic
experiences. These findings place new
weight on calls for more comprehensive preventions and intervention strategies
against childhood trauma in the community from abuse at home and bullying in
The study aimed to determine whether childhood trauma could be considered a cause of
psychotic experiences. In order for something to be genuinely considered 'a
cause', it has to show a number of characteristics such as, a strength of
association - namely the stronger the association the more likely that it is
causal; a dose-response relationship - as the dose increases, so should the
odds of the outcome or cessation of exposure - if exposure ceases or decreases,
then the odds of the outcome should also cease or decrease.
Professor Cannon, continued “Our findings showed a clear relationship between exposure to
childhood trauma and the onset of psychotic symptoms because the strength of
the relationships was large in terms of odds ratios. We also saw a dose-response relationship with
the odds of psychotic symptoms increasing in line with increasing levels of
Dr Ian Kelleher, Lead Investigator, Department of Psychiatry, RCSI said “Our analysis
shows, we believe for the first time, that cessation of traumatic experiences
predicted a significantly reduced incidence of psychotic experiences compared
to individuals for whom the traumatic experiences continued. This is a very encouraging
finding and suggests that population based approaches could have a large impact
reducing the prevalence of psychotic symptoms.”
“The research found that 'classmates' were the largest group inflicting physical
harm. Additionally, as most bullying taking place within the school, teacher
training could have a very important role to play in reducing this harm,” said Dr
The full paper is available from the American Journal of Psychiatry.
Dr Helen Keeley and Dr Paul Corcoran of the National Suicide Research Foundation were co-investigators on this research.