Multi-modal hallucinations across diagnoses: What relationships do they have with voice-related distress?

Background: Research into hallucinatory experiences has focused primarily upon hallucinations within the auditory modality, to the relative neglect of other modalities. Furthermore, the exploration of auditory hallucinations (or 'voices') has focused primarily upon the experiences of people with a diagnosis of psychosis. The presence of multi-modal hallucinations may have implications across diagnoses for levels of distress, formulation and the targeting of psychological interventions.

Methods: This study presents a cross-sectional analysis of observational data from the PREFER survey (N = 335). Linear regression was used to explore the relationships between voice-related distress and the presence, number, type and timing of multi-modal hallucinations.

Results: Simple relationships were not found between distress and the presence of hallucinations in visual, tactile, olfactory or gustatory modalities, or in the number of modalities experienced. When considering the degree to which another modality hallucination was experienced simultaneously with voices, there was some evidence that the degree of co-occurrence with visual hallucinations was predictive of distress.

Conclusions: The co-occurrence of voices with visual hallucinations may be associated with relatively greater distress, but not consistently, and the association between multimodal hallucinations and clinical impact appear complex and potentially variable from individual to individual. Further study of associated variables such as perceived voice power may further illuminate these relationships.