Bodily Self-Disturbances and Hallucinations in Schizophrenia.

BACKGROUND AND HYPOTHESIS: Auditory verbal hallucinations experienced by people with schizophrenia are primarily described in terms of unusual perceptual experiences. However, they also involve profound self-disturbances. More specifically, they are deeply intertwined with disorders of the sense of bodily self. Sometimes hallucinations in schizophrenia are experienced as invading the body, whereas other times they seem to help to delineate a frontier between oneself and others. STUDY DESIGN: As one of the working groups at the 2023 biennial meeting of the International Consortium on Hallucination Research (ICHR), here we review the disorders of the sense of bodily self in schizophrenia and delineate the link between these disturbances and auditory verbal hallucinations. STUDY RESULTS: We report findings suggesting that peripersonal space, interoception, timing, and the vestibular system may all be disturbed in schizophrenia and that there may be reciprocal influences between bodily self-disturbances and hallucinations in this condition. CONCLUSIONS: Schizophrenia is associated with multiple sensory disturbances that contribute to the sense of bodily self. How these disturbances interact remains to be explored. The relationship between weakened sense of the bodily self and hallucinations in schizophrenia is rather complex, with some evidence suggesting that hallucinations in schizophrenia may both contribute to disturbances in the sense of self and, in some cases, temporarily restore self-other boundary. Future studies are needed to establish the causal and bidirectional aspects of these relationships. We can envisage several therapeutic approaches based on the available findings, which will likely have to be adapted to the patients' own needs.