Psychosis and voice-hearing: exploring dissociative processes and factors associated with compliance with commanding voices

Voice-hearing (VH) is prevalent for people with a psychiatric diagnosis of psychosis. Previous research has found that some individuals hear voices that are commanding in nature. However, the factors linked to whether a person complies, or does not comply, with commands are not well understood. Therefore, section one of this thesis aimed to review literature examining variables thought to be related to compliance with commanding voices.

A systematic literature review was completed, where three online databases were searched for relevant studies. In total, 14 papers were included, which considered a range of variables. The quality of included studies was assessed, which highlighted issues with both reliability and validity. Due to methodological differences between studies, it was difficult to directly compare studies and draw firm conclusions. However, there was some evidence that compliance was related to voice-related variables, including recognising the voice, higher
ratings of perceived voice power, the presence of consistent unusual beliefs and voice-hearer characteristics, including increased illness severity and stronger beliefs about future compliance.

The current review provides initial information on several variables thought to be related to compliance with commanding voices. However, the current evidence is limited and further research, of high quality, is required to further inform current understanding and clinical practice. It is recommended that clinicians ask clients about their voice-hearing experiences and assess variables associated with compliance (e.g., the presence of consistent unusual beliefs) to support risk assessment and management and inform treatment targets. It is also
recommended that psychological interventions address issues of compliance, for example by reducing perceived voice power.

The second section of this thesis consists of the empirical project. This online study aimed to compare participants with psychosis and post-traumatic stress disorder (PTSD) on factors considered to be related to VH, including trauma and dissociation. The relationship between peritraumatic dissociation and VH was also explored. Although peritraumatic dissociation has been linked to trauma-related conditions, including PTSD, it has not been examined in psychosis.

A total of 81 adults participated in this project. Participants were recruited to one of three groups (27 per group) based on whether they had a diagnosis of psychosis, PTSD, or no current mental health diagnosis (excluding anxiety or depression). Recruitment was attempted via local NHS services and social media. However, all participants were recruited through social media (e.g. Facebook). Participants were given a link to the study, where they answered demographic questions and completed questionnaires measuring childhood trauma,
dissociation and peritraumatic dissociation. Participants also completed an online signal detection test to support data collection for a separate study.

The psychosis and PTSD groups reported increased childhood trauma, dissociation and peritraumatic dissociation. VH was mediated through childhood trauma, peritraumatic dissociation and dissociation. The findings provide initial evidence that peritraumatic dissociation is relevant to psychosis as well as PTSD. However, due to limitations of this exploratory study, further research using larger samples and clinical populations is required. It is recommended that clinicians routinely screen trauma, dissociation and peritraumatic dissociation in patients with psychosis and PTSD.