Disturbance of minimal self (ipseity) in schizophrenia: clarification and current status.

The assessment of psychopathology in most contemporary research is based squarely on signs and symptoms of disorder, often measured in fairly crude checklist-type fashion. This approach has tended to indicate significant overlap in psychotic and other symptoms across disorders , eg, between schizophrenia and bipolar disorder 1 and between psychotic disorders and borderline personality disorder. 2 This may partly be the result of the assessment tools and conceptual frameworks being used. By contrast, insights from phenomenological psychiatry and philosophy, focused on disturbed subjectivity, 3 indicate that disturbed self-experience or selfhood may underlie and generate many " surface-level " psychotic symptoms, particularly in schizophrenia spectrum disorders. There are many different meanings and controversies surrounding the notion of the " self. " 4 These controversies mainly concern its ontology or ultimate reality status, eg, as a kind of " substance, " object, or process. The experi-ential, subjective notion of the self (the sense of self) is, however, widely acknowledged, both in the analytic philosophy of mind 5 and in phenomenology. 6 Two levels of the experiential self are typically proposed: 1. " Minimal " self, also referred to as " basic " or " core " self or as " ipseity. " This is a prereflective, tacit level of selfhood. It refers to the implicit first-person quality of consciousness, ie, the implicit awareness that all experience articulates itself in first person perspective as " my " experience. In other words, all conscious acts are intrinsically self-conscious, 7 a feature sometimes designated as " self-affection. " " Minimal " or " core " self constitutes the foundational level of selfhood on which other levels of selfhood are built. 6–8 2. " Narrative " or social self. This refers to characteristics such as social identity, personality, habits, style, personal history, etc. Psychological concepts such as " self-esteem " or " self-image " refer to this level of selfhood. This level is widely understood to presuppose the sense of existing as a subject of experience (" minimal self ") and often involves reflective, metacognitive processes, in which one's self is largely an object of awareness. Many classic and early texts about schizophrenia proposed that disturbance of minimal self is at the core of the disorder , 11,12 a view reinforced and extended by recent empirical studies (see below). The ipseity-disturbance model (IDM), developed by Sass and Parnas, presents distortion/instabil-ity of the minimal self as consisting …