Waiting times for evidence-based psychological therapies is a source of concern for healthcare systems globally. Alternatives to traditional face-to-face talking therapies are needed. Self-help interventions can be used independently of contact with a healthcare professional, and offer a degree of flexibility and discretion that can better suit the needs of some individuals. Self-help interventions are widely used for common mental health difficulties, but the application of these approaches to severe mental health difficulties like psychosis is under-researched.

This thesis aims to build in this area. Part A is a systematic review of CBT-informed guided and unguided self-help interventions that have been tested with people with psychosis, and what components make up the interventions. Findings of this study suggest relatively few interventions have been made, with most in the feasibility stages and largely heterogeneous from one another despite all utilising a CBT approach. This study argues that greater consistency of approach, and a focus on factors that improve engagement, would help the literature more out of its nascent stage into a more coherent body of evidence.

Part B focusses on engagement with self-help as experienced by people who experience distressing auditory verbal hallucinations, an experience commonly associated with psychosis. Participants from an ongoing NHS research trial of a guided self-help intervention for distressing auditory verbal hallucinations were interviewed as to what factors made it easier, or harder, for them to make use of the intervention. Reflexive Thematic Analysis of the interviews suggested that personal resources and capacity to engage with self-help, the perceived credibility and accessibility of the self-help intervention itself, and relationship with the guides all appeared to modulate engagement. Part B concludes with suggestions as to how self-help could be made easier to engage with for people who experience auditory verbal hallucinations, which may inform design and implementation of self-help for this population.