title: Self-other factors in a psycho-developmental model of psychosis vulnerability
Creators: name: Ozdemir, Ercan
Publisher: name: The University of Edinburgh
Year: 2025
Subjects: subject: Schizotypy
subject: Psychosis Vulnerability
subject: Mentalization
subject: Attachment
subject: Disorganized Schizotypy

description: Schizotypy is a theoretical construct posited in the 1950s to study psychosis vulnerability in the domains of social relatedness (negative schizotypy), self-experiences (disorganized schizotypy), and meaning making processes (positive schizotypy). Since the mid-20th century, schizotypy has generated extensive research supporting its validity in representing a psychosis vulnerability construct. However, a developmental model of psychosis vulnerability based on schizotypy is yet to be formulated. The thesis presents a developmental model of psychosis vulnerability based on two lifespan theories of affect regulation: attachment and mentalization. Attachment refers to the capacity to form emotional bonds facilitating a sense of security in the world and mentalization refers to the capacity to reflect on self-experiences to make sense of the self and the world, implicating such capacities as increasing the risk of psychosis development. The thesis formulated a developmental model of schizotypy that was then tested empirically by exploring the relationships between different dimensions of psychosis vulnerability, attachment and mentalization in order to understand a specific pathway to psychotic decompensation rooted in self-other processing. The assessment of the theoretical model involved a systematic review and four interlinked studies. The associations between mentalizing difficulties in understanding affective self-experiences and schizophrenia and psychosis vulnerability were systematically reviewed and meta-analyzed in Chapter 2. The primary research consisted of two cross-sectional studies (Chapters 4 and 6), a 2-wave cohort study (Chapter 5), and an experience sampling study (Chapter 7), all using self-report assessments. Participants were recruited from the general population and sample characteristics suggested that the examined phenomena related to psychosis vulnerability were well represented across the samples. In Chapter 4, a cross-sectional model was estimated via structural equation modeling to evaluate the extent to which theoretically defined associations between the dimensions of psychosis vulnerability, attachment, mentalization, and negative affect fitted the observed data from a sample of n = 1263. Chapter 4 was the baseline study, from which the rest of the study samples were derived. In Chapter 5, the theoretical model was cross-validated contemporaneously and temporally via network modeling methods based on n = 312 participants who took part in the 6-month follow-up assessment. Chapter 6 presents an exploratory cross-sectional study (n = 416) based on the gaps identified in the systematic review of Chapter 2, estimating the differential associations between the dimensions of psychosis vulnerability, mentalizing capacity, and negative affect using a cross-sectional network model. Finally, Chapter 7 utilized an experience sampling design (n =43) to model the concurrent and cross-lagged associations between psychotic experiences, mentalization, and anxiety based on a structured self-report assessment with 56 measurement occasions in total. The findings of the studies collectively showed that mentalizing capacity is robustly associated with psychosis vulnerability and is implicated in maintaining psychotic experiences. Cross-sectionally, mentalizing difficulties – defined as mental state uncertainty – exerted the influences of childhood trauma, negative schizotypy, and depression on self-experiences denoted by disorganized schizotypy and attachment disorganization (Chapter 4). In a subsequent study, temporal modeling indicated that disorganized schizotypy predicted uncertainty about mental states, which in turn predicted positive schizotypy (e.g., magical ideation and perceptual aberrations) and negative schizotypy across a 6-month period. Contrary to the theoretical model, psychosis vulnerability conferred risk for higher indices in attachment insecurity and disorganization (Chapter 5). A cross-sectional network model suggested that difficulty in identifying affective self-experiences was the most central variable connecting negative affect to psychosis vulnerability (Chapter 6). Furthermore, difficulties in identifying and expressing affective self-experiences were implicated in the persistence of psychotic experiences (Chapter 7). In summary, the thesis presents a theoretical model for conceptualizing psychosis vulnerability from a developmental perspective and provides empirical support for the theoretical model based on findings from meta-analytic, cross-sectional, longitudinal, and momentary assessment studies. The evidence presented suggests that mentalization links psychosis vulnerability to psychotic experiences via negative affective reactivity to stress, while difficulties in reflective forms of mentalizing and disorganization in the attachment system may be maintained by schizotypal disorganization. Among the psychosis vulnerability dimensions, disorganized schizotypy has been a neglected domain in theory, research, and practice. The thesis identifies schizotypal disorganization as a central dimension of psychosis vulnerability in conferring risk for the development of psychotic experiences. Interventions that facilitate mentalizing capacity may mitigate the risk of psychosis by enhancing the coherence and organization of narrative self-experience and fostering resilience against distress.