The role of self-disturbances and cognitive biases in the relationship between traumatic life events and psychosis proneness in a non-clinical sample.

BACKGROUND: Traumatic life events have been established as an environmental risk factor for psychosis. However, the exact mechanisms by which traumatic life events increase risk for psychosis are unknown. In the present study we tested an integrative model of traumatic life events being related to psychosis proneness via self-disturbances and cognitive biases.

METHODS: The sample consisted of 653 healthy people. Traumatic life events, self-disturbances, cognitive biases and psychosis proneness were assessed with self-report questionnaires. The direct and an indirect model of the relationship between traumatic life events and psychosis proneness were compared using path analyses with structural equation modelling in a cross-sectional study.

RESULTS: There was a significant direct effect of traumatic life events on psychosis proneness. However, path analysis suggested better fit of the indirect model including paths from trauma to psychosis proneness via cognitive biases and self-disturbances. There were significant paths from traumatic life events to cognitive biases and self-disorders. Self-disorders significantly predicted cognitive biases. Finally, cognitive biases and self-disorders significantly predicted psychosis proneness. Exclusion of any paths, apart from direct path in the model, significantly reduced model fitness.

DISCUSSION: The results revealed that a direct relationship between trauma and psychosis proneness became insignificant when taking into account the influence of self-disorders and cognitive biases. This suggests that the interactions between disrupted self-experience, impaired information processing and traumatic life events are of importance in psychosis proneness. This model should be further tested in a longitudinal study on a clinical sample.