Implicit self-esteem: conceptualisation, measurement & contribution to understanding how childhood trauma causes paranoia

Childhood trauma is a known risk factor for the later development of paranoia and persecutory delusions, however the mechanism of action is unclear. An influential model of persecutory delusions (‘delusions-as-defence’) predicted that paranoia may also arise as an unintended consequence of a bias towards holding other people responsible for negative events, the aim of which is to prevent low implicit self-esteem reaching awareness. Whether this model, and low implicit self-esteem specifically, may help to explain the effect of childhood trauma on paranoia has not been investigated. This thesis first set out to understand the nature of implicit self-esteem by conducting a systematic meta-review of 39 existing systematic and non-systematic reviews addressing its conceptualisation, measurement and correlates, as well as what interventions can modify it. Network analysis, mediation analysis and structural equation modelling (SEM) of data gathered from a large population sample (n=1052) was then used to determine whether or not implicit self-esteem, and other key variables implicated in the ‘delusions-asdefence’ model (explicit self-esteem, attributional biases) or in the development of paranoia more generally (self-concept clarity, negative self-schemas), help to account for the effects of childhood trauma on non-clinical paranoia. An exploratory model, driven by the data but constrained by theory, was developed based on fit indices, explanatory power and parsimony. This model was then tested prospectively in another large population sample (n=617), using SEM. The results and implications are discussed in the context of psychological models of paranoia.