Psychological processes involved in psychosis symptomatology: the role of dissociation and reality discrimination.

Abstract

This thesis has been prepared in a paper based format, comprised of three papers. Paper 1, a systematic review; Paper 2, an empirical study; and Paper 3, a critical appraisal and evaluation of the work. Paper 1 presents a systematic review of the association between dissociation and psychosis symptomatology. A systematic literature search was conducted using four electronic databases; Web of Science, PsycINFO, Embase and Pubmed. Forty studies satisfied inclusion criteria for the review. These assessed the relationship of dissociation with hallucinations, delusions, paranoia, positive symptoms, negative symptoms and schizotypy. Significant associations were found between dissociation and all symptoms of psychosis, and this finding was consistent across clinical and non-clinical populations. Recommendations are made for future research to control for the high level of co-occurrence of different symptoms of psychosis, and to consider psychological mechanisms that may play a role in the relationship between dissociation and psychosis. Paper 2 presents an experimental study assessing a proposed two-hit model of voice-hearing whereby dissociation triggers voice-hearing in people already vulnerable to reality discrimination errors. An experimental study was conducted to assess the relationship between dissociation, reality discrimination and voice-hearing proneness in a clinical sample of 50 participants. Findings did not support the two-hit model of voice-hearing. Interpretations of the findings are discussed alongside consideration of limitations in the study design. Paper 3 is a critical appraisal of the systematic review, the empirical paper and the research process as a whole. This includes reflecting on strengths and weaknesses of the papers, and personal reflections on the experience of conducting research.

Date of Award	31 Dec 2017
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Katherine Berry (Supervisor) & Sandra Bucci (Supervisor)