A phenomenological study of auditory verbal hallucination in psychosis

Abstract

Introduction: Patients of schizophrenia experienced a cluster of symptoms known as psychosis, which were concurrent phenomena presented across multiple psychopathological dimensions, among which hallucination was one of the principal features. Auditory verbal hallucination (AVH) was the most common among other modalities (i.e. visual, olfactory, gustatory and tactile) of hallucinations and was said to occur when audible voices were heard without presence of corresponding stimuli. There were two main neurocognitive hypotheses on the underlying mechanism of the occurrence of AVH, namely the inner speech hypothesis and the top down processing hypothesis. Existing descriptive psychopathology studies were not guided by any theoretical frameworks. This study was the groundwork to examine experiences of AVH as described by patients with psychosis and other psychiatric conditions based on these two major hypotheses.

Method: This study was a retrospective case series. Comprehensive searches of AVH cases were done on biomedicine and psychology databases, in which case reports, case studies and studies with detailed descriptions of phenomenology of AVH with various aetiologies, a total of twenty cases, were selected. Four in-depth qualitative interviews were also conducted with psychosis patients for in-depth understandings of their AVH phenomena experiences.

Result: Three specific features from the two neurocognitive hypotheses were identified. (1) Form of address, (2) linguistic complexity, and (3) command hallucinations were likely interpreted by inner speech hypothesis; whereas (1) single theme and repetitive contents, (2) relations with past experience/knowledge/perceptual expectations, and (3) congruent moods were likely interpreted by top down processing bias hypothesis.

Discussion: This study has categorized AVH phenomena from twenty literature cases and four in-depth qualitative interview cases by specific features of the two mainstream hypotheses; and commented on each of the specific features on their relevancies to the two mainstream hypotheses. Conceptualisation of underlying neurocognitive mechanisms could made taxonomy easier, and as a result benefit clinical staging, better prediction of prognosis and better communications with patients and their families.