Shades of vulnerability: latent structures of clinical caseness in prodromal and early phases of schizophrenia

Abstract

The underlying structures of clinical caseness and need of care in prodromal (i.e., at-risk) and early phases of schizophrenia remain poorly characterized in their essential psycho-behavioral coherence. To identify the schizophrenia proneness-related subtypes within a population of young help-seekers referred to a dedicated, community-based early detection program (Programma 2000). A sample of consecutive referrals (n=168) for suspected psychosis or first-episode schizophrenia spectrum psychosis received a detailed clinical assessment, including the early recognition inventory for the retrospective assessment of the onset of schizophrenia checklist. We used exploratory factor analysis (EFA) to determine the underlying dimensional structure and latent class analysis (LCA) to identify putative vulnerability subtypes. EFA identified four factors: dysphoria (irritability tension), paranoid autocentrism, introversive withdrawal, and disturbed subjective experience. LCA distinguished three classes, interpretable as carrying different degrees of "proneness to schizophrenia psychosis," which best captured the underlying continuum of clinical severity. The validity of the three classes was supported by distinct patterns of association with major clinical variables (i.e., diagnostic staging at referral). Vulnerability to schizophrenia psychosis in young help-seekers may manifest in three major clinical prototypes, presenting common levels of dysphoria and social withdrawal but different degrees of paranoid autocentrism and disturbed subjective experience. Overall, the results provide the empirical background to dissect shared features of clinical caseness from more schizophrenia-specific vulnerability components. This is of value for the refinement of the clinical staging model as well as for the pragmatic implementation of multiple-gate screening programs.