Measuring and Understanding the Phenomenology and Content of Hallucinations

Abstract

Historically regarded as a symptom of psychosis, more recent research has indicated that hallucinations may be transdiagnostic, phenomenologically diverse, and associated with traumatic and adverse life experiences. Psychological models have struggled to account for this range of hallucinatory experience. A better understanding of how traumatic experiences relate to hallucinations, and of the diversity of this phenomenon could have valuable implications for psychological theories and therapies for hallucinations. A systematic literature review (Paper 1) examined the relationship between trauma and the content and characteristics of hallucinations. A large majority of included studies identified a relationship, including direct relationships, such as parallels in terms of perpetrator and voice identity, and thematic relationships, such common themes of threat. The findings were explored in the context of psychological theories of hallucinations, including drawing on the existing literature on re-experiencing symptoms as found in post-traumatic stress disorder. Various methodological limitations of the literature are discussed. An empirical study (Paper 2) sought to develop the Dimensions of Voices Questionnaire. An exploratory factor analysis revealed different dimensions which were termed memory-related hallucinations, threat-related hallucinations and linguistic complexity hallucinations. Certain demographic characteristics of the sample limit generalisability, perhaps due to the study being online. Further research is needed to ascertain replication of the factor structure in an independent sample. A critical evaluation (Paper 3) is presented, which describes in more detail some of the decisions made in the above papers, and further explores the strengths and limitations of this work.

Date of Award	31 Dec 2018
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Anthony Morrison (Supervisor) & Filippo Varese (Supervisor)