Trauma and Psychosis: Investigating the Role of Post-Traumatic Intrusions, Schemas and Avoidance Natalie Louise Peach ORCID I D 0000-0001-5037-9619 Submitted in partial fulfilment of the degree of Master of Psychology (Clinical Psychology)/Doctor of Philosophy November 2016 Department of Psychology The University of Melbourne Abstract Increasing evidence suggests that childhood trauma may play a role in the aetiology of psychosis, leading to suggestions that trauma-related symptoms may be mechanisms in the process. Two prominent cognitive models implicate post-traumatic intrusions and trauma-related schemas and emotion as key mechanisms. Neither of the models has been extensively tested, and both have implications for the content of hallucinations and delusions in relation to traumatic experiences. The aims of the current study are to 1) investigate statistical associations between the severity of trauma and psychosis, 2) investigate phenomenological associations between trauma, post- traumatic intrusions, hallucinations and delusions, and 3) explore the relationship between trauma- related avoidance and psychosis. Sixty-six people with first episode psychosis aged between 15 and 24 years were assessed for childhood trauma, post-traumatic stress disorder (PTSD) symptoms, psychotic symptoms and experiential avoidance. The content of hallucinations, delusions, post-traumatic intrusions and traumatic experiences (up to five of each) was assessed. Content relationships between hallucinations, trauma and post-traumatic intrusions were categorised as ‘direct’ (where hallucination content was identical to trauma or intrusion content), ‘indirect’ (where hallucinations contained elements of trauma/intrusion-specific content but were not exact representations of traumas/intrusions) or ‘thematic’ (where hallucinations were related to trauma or intrusions at the level of broader, schema-related themes). Sixty-five percent of the sample had experienced childhood trauma, and 26% met diagnostic criteria for PTSD. Childhood trauma severity was correlated with hallucination and delusion severity with moderate effect sizes (although the correlation with hallucinations did not i reach significance). Post-traumatic intrusions correlated with both hallucinations and delusions with moderate to large effect sizes. In terms of hallucination content, 78% of people with hallucinations and childhood trauma had hallucinations related in content to their trauma. These relationships were primarily thematic, although a notable minority (25%) had hallucination content directly representative of their trauma. Sixty-four percent of people had more than one type of relationship (direct, indirect, thematic, or no relationship) between their trauma and hallucination content. Of those with hallucinations and post-traumatic intrusions, 73% experienced hallucinations related in content to their post-traumatic intrusions. For delusion content, 89% of people with delusions and trauma had delusional content related to their trauma. Relationships between childhood trauma, avoidance, hallucinations and delusions were investigated, and it was found that childhood trauma was correlated with experiential avoidance (with a moderate effect size), and that both experiential avoidance and post-traumatic avoidance were correlated with hallucinations and delusions (with moderate effect sizes). In a series of multiple linear regressions, post-traumatic intrusions (but not childhood trauma, post-traumatic avoidance, experiential avoidance or maladaptive schemas) were independently associated with hallucination severity and explained 13% of the variance in hallucinations. Post-traumatic intrusions and maladaptive schemas (but not childhood trauma, post-traumatic avoidance or experiential avoidance) were independently associated with delusion severity, and explained 14% and 5-8% of the variance in delusion severity respectively. These findings suggest that post- traumatic intrusions and maladaptive schemas may be particularly important mechanisms in the relationship between trauma and psychosis, and may be playing a stronger role than avoidance. This has implications for the treatment of trauma and PTSD symptoms in people with psychosis. ii Research trialling interventions that specifically target post-traumatic intrusions and schemas in people with early psychosis who have experienced childhood trauma is recommended. iii Declaration This is to certify that: (i) the thesis comprises only my original work towards the degree of Master of Psychology (Clinical Psychology)/Doctor of Philosophy (ii) due acknowledgment has been made in the text to all other material used (iii) the thesis is fewer than 100,000 words in length, exclusive of tables, maps, bibliographies and appendices Natalie Louise Peach I, Natalie Louise Peach, declare that the research reported in this thesis was conducted in accordance with the principles for the ethical treatment of human participants, as approved for this research by the University of Melbourne Human Research Ethics Committee. Natalie Louise Peach iv Acknowledgments I would like to thank my three supervisors for their continuous support throughout this PhD. Firstly to Dr Sarah Bendall; her guidance and advice was an immense help at every stage of conducting the research and writing the thesis. Sarah, I could not have imagined having a better supervisor. I have learned so much from your research knowledge and clinical experience. Thank you so much for all your detailed feedback on my writing, for the use of your own thesis as a template, and for your constant kind words of encouragement. Thank you also to Dr Simon Cropper for the support and assistance throughout this process. Simon I have really appreciated having your perspective, your flexibility and your empathetic outlook in regards to the lives and experiences of the participants in the study. My thanks also to A/Prof Mario Alvarez-Jimenez for your input to the study and for your valuable feedback, particularly in the later stages. Your research expertise and warm encouragement was greatly appreciated. Thank you to the Chair of my Advisory Committee A/Prof Carol Hulbert, who has been extremely positive and encouraging from the beginning of this process and has offered constructive feedback throughout. Thanks to everyone at Orygen. To the participants who volunteered to be in the study, for their time and effort sharing their stories and insights into their experiences. Thanks to the Orygen case managers who referred clients to participate. Thank you to my friends and fellow research students for all the support and motivation over these last few years. Particularly to Pam Sun for all your amazing efforts with our data collection and for your friendship along the way; and to Janet Tong for all your cheery optimism as my most motivating writing buddy! v Finally, my most special thanks to my parents for everything they have done to support me in this over the years. Also to my sisters Beth and Laura, and my brother Adel for being constant sources of upliftment and encouragement. vi Table of Contents Abstract .................................................................................................................................. i Declaration........................................................................................................................... iv Acknowledgments ................................................................................................................ v Table of Contents ............................................................................................................... vii List of Tables ...................................................................................................................... xii Chapter 1. Introduction and Overview .............................................................................. 1 1.1 GENERAL INTRODUCTION................................................................................. 1 1.2 OUTLINE OF THE CHAPTERS OF THE THESIS ............................................... 4 Chapter 2. Trauma, PTSD and Psychosis ......................................................................... 7 2.1 TRAUMA IN PEOPLE WITH PSYCHOSIS .......................................................... 7 2.1.1 Historical Focus on Biological vs Social Factors .......................................... 7 2.1.2 Rates of Trauma in People with Psychosis ..................................................... 8 2.1.3 The Question of Causality ............................................................................ 12 2.2 PTSD AND PSYCHOSIS ..................................................................................... 15 2.2.1 Rates of PTSD in People with Psychosis ...................................................... 15 2.2.2. Low Detection in Clinical Settings .............................................................. 21 2.2.3 Severity Associations .................................................................................... 22 2.2.4 Hallucinations and Delusions in PTSD ........................................................ 22 2.3 PTSD AND PSYCHOSIS AS DIAGNOSTIC CATEGORIES ............................ 23 2.3.1 The Formulation of PTSD as a Diagnostic Construct .................................. 23 2.3.2 Complex Trauma and Complex PTSD .......................................................... 24 2.3.3 Symptom Overlap in PTSD and Psychotic Disorders .................................. 25 2.4 POSITIVE