Researchers have published strong evidence from a large sample of adolescents that trauma leads to psychosis. But, in an encouraging finding, the ceasing of trauma (bullying or physical abuse) was associated with a clear reduction in psychotic experiences.
"These findings place new weight on calls for more comprehensive prevention and intervention strategies against childhood trauma in the community, from abuse at home to bullying at school," say lead study author Ian Kelleher (Royal College of Surgeons in Ireland, Dublin) and team.
"Our findings provide the first direct evidence that this may lead to a reduced incidence of psychotic experiences in the community and ultimately, we hope, a similar reduction in the incidence of psychotic disorders."
The 1,112 schoolchildren (aged 13–16 years) in the study completed a survey three times over the course of 12 months, during which 5–7% reported psychotic experiences, 8–10% reported physical assault, and over a third experienced bullying.
The research team found a "clear temporal relationship" between trauma and psychosis, with children who reported bullying or assault having a significant four to sixfold increased risk for psychotic experiences at the follow-up surveys, even after accounting for psychotic experiences at baseline. Moreover, the association was dose-dependent, with the risk rising in line with the number of positive responses to six questions related to bullying.
However, children whose experiences of assault did not recur between two surveys had a more than 80% reduction in risk for psychosis, relative to those whose experiences continued. Likewise, the risk for psychosis was reduced by around 70% if bullying ceased, compared with if it continued.
Interestingly, the association between trauma and psychosis worked both ways, with baseline psychotic experiences increasing the risk for bullying up to fivefold and assault up to 12-fold, even after accounting for trauma at baseline.
The researchers speculate that children with psychosis may behave in a way that attracts bullying or assault, or that their social circumstances may be a risk factor for both trauma and psychosis.
Another explanation "is that children with psychotic experiences may interpret negative interactions with others in a more paranoid way and may be more likely than children without psychotic experiences to label such experiences as bullying," they write in The American Journal of Psychiatry.
However, Kelleher stresses that the bidirectional relationship does not affect their main finding, as it held true when children with baseline psychotic experiences were removed from the analysis.