Thinking, believing, and hallucinating self in schizophrenia

In this Personal View, we discuss the history and concept of self-disturbance in relation to the pathophysiology and subjective experience of schizophrenia in terms of three approaches: the perceptual anomalies approach of the early Heidelberg School of Psychiatry, the ipseity model, and the predictive coding framework. Despite the importance of these approaches, there has been a notable absence of efforts to compare them and consider how they might be integrated. This Personal View compares the three approaches and offers suggestions as to how they might work together, which represents a novel position. We view self-disturbances as transformations of self that form the inseparable background against which psychotic symptoms emerge. Integrating computational psychiatric approaches with those used by phenomenologists in the first two listed approaches, we argue that delusions and hallucinations are inferences produced under extraordinary conditions and are both statistically and experientially as real for patients as other mental events. Such inferences still approximate Bayes-optimality, given the personal, neurobiological, and environmental circumstances, and might be the only ones available to minimise prediction error. The added contribution we hope to make focuses on how the dialogue between neuroscience and phenomenology might improve clinical practice. We hope this Personal View will act as a timely primer and bridging point for the different approaches of computational psychiatry and phenomenological psychopathology for interested clinicians.