Despite their importance, there has been a notable absence of efforts to compare them and to consider how they might indeed work together. Self-disturbances are transformations of basic self that form the inseparable background against which psychotic symptoms emerge. Integrating computational psychiatric approaches with those employed by phenomenologists, we understood delusions and hallucinations as inferences produced under ‘extraordinary’ conditions and would be both statistically and experientially as real for patients as other mental events. Such inferences still approximate Bayes-optimality given the circumstances and may be the only ones available to minimise prediction error.
Most people would never wonder, let alone doubt, whether the thoughts they think are indeed their own. However, in cases of self-disturbances found in schizophrenia and related psychoses, the ‘minimal self’ is damaged (but still never truly absent) and susceptible to anomalous experiences such as confusing internal mental events with external stimuli. The Early Heidelberg School of Psychiatry defined self-disturbances as something that did not arise from impaired conscious self-acquaintance (ipseity), but rather would involve unconscious processing. On the other hand, the ipseity model by Sass and Parnas proposes a heightened self-awareness leading to the alienation of mental events and places lessemphasis on unconscious processing. Nevertheless, there was common ground between these models, such as the convergence on the ‘Basic Symptom’ concept.
Even from a purely neuroscientific point of view, as shown by the Bayesian inference framework, delusions are still the best hypotheses the patient can generate and to a certain degree defend, given the unusual circumstances. It should be borne in mind that schizophrenia carries the heavy burden of stigma even in the clinic because some clinicians do not (and perhaps refuse to) understand the illness, and not that patients living with the illness cannot understand their clinicians. After all, there are intersects between the patients’ and the clinicians’ experiences of reality. By beginning to seek these intersects, a therapeutic dialogue would surely ensue.