Background: It has been proposed that voice hearing, even in the context of psychosis, is associated with high levels of dissociation - especially amongst individuals with a history of childhood abuse. This thesis studies these relationships using more rigorous research methods than have been applied in much existing observational work, and contributes original evidence for understanding the incidence of, and associations between, voice hearing, dissociation, and life adversity (particularly childhood sexual abuse: CSA) in a first-episode psychosis sample.
Study 1 and 2: Evaluates current knowledge on associations between (1) voice hearing and dissociation, and (2) voice hearing and CSA using systematic, critical literature review. Both studies found strong associations between key variables, although methodological limitations in the literature preclude assumptions of causal relationships.
Study 3: Employs self-report measures and a retrospective case-control design to assess voice hearing, dissociation, psychological distress, and adversity exposure within a pseudo-random sample of voice hearers (n=31) and non-voice hearing controls (n=31). CSA and dissociation were significantly higher amongst case participants. Dissociation retained a significant association with voice hearing when controlling for pre-illness adversity exposures and psychological distress.
Study 4: Employs self-report measures and a cross-sectional between-groups design to assess dissociation, distress, and voice phenomenology within a pseudo-random sample of voice hearers with (n=23) and without (n=23) self-reported CSA exposure. CSA severity was associated with higher dissociation. Both groups reported similar voice characteristics, although CSA survivors perceived voices as more omnipotent. Emotional responses to voices showed strongest associations with psychological distress when controlling for dissociation and adversity exposure.
Summary: Considerable heterogeneity was apparent for all measures between and within groups of voice hearers and non-voice hearers, and voice hearers with and without CSA exposure. Associations between voice hearing and dissociation remain significant when controlling for adversity exposure and the type of stress, anxiety, and depression that occurs in the more general context of psychosis. However, while dissociation increases the likelihood of voice hearing per se, psychological distress has stronger associations for experiencing voices as negative. The datasets are interpreted within the context of wider clinical/conceptual debates around the role of dissociation, distress, and adverse life events in psychosis, and are used to generate recommendations for both therapeutic intervention and future research.
