Enhancing the clinical utility of the psychosis-risk concept: a network and transdiagnostic perspective

Psychotic disorders are associated with significant personal and societal costs, reduced life expectancy, and diminished occupational achievements. The clinical high risk for psychosis (CHR-P) paradigm prospectively focuses on the at-risk phase that may precede the psychosis onset, with the goal of delaying or even preventing first-episode psychosis. Despite this clinical and research model has gained traction worldwide, several scholars have questioned its clinical relevance, also questioning the very concepts of “risk for” and “transition to” psychosis. This thesis provides a formal definition of the “clinical utility” of the CHR-P state and assesses its relevance for diagnosis, enrollment, intervention, and prognosis through a network analysis statistical approach, addressing stigma, and adopting a transdiagnostic approach. Four studies were included in the thesis. The first cross-sectional study focused on CHR-P individuals and clinical controls, showing that the network structure of CHR-P individuals can be differentiated from clinical controls, suggesting clinical specificities of the CHR-P state. In the second survey study in a sample of clinicians, young people, and their relatives, diagnostic terms and clinical strategies were identified for referring to the psychosis-risk state that are clinically communicative and associated with low stigma. In the third study, a scoping review of existing literature revealed no unified approach for treating individuals with both CHR-P state and borderline personality disorder. 10 research recommendations were also generated toward paradigm integration. In the fourth study, network analysis of baseline positive and basic symptoms did not differentiate CHR-P individuals who later transitioned to psychosis from those who did not. Overall, this thesis supports the clinical utility of the CHR-P paradigm, identifies informative, non-stigmatizing terms for communicating the psychosis-risk concept, proposes intervention targets, and suggests future directions for transdiagnostic and prognostic research.