**4. Conclusions**

**3.2. Toward a comprehensive assessment of psychotic-like experiences**

maintenance of mental health [34, 35].

12 Psychosis - Biopsychosocial and Relational Perspectives

risk factors [28, 64].

A comprehensive and phenomenological differentiated description of psychotic-like experiences (PLE) might be the prerequisite for attaining reliable classifications of PLE and new insights regarding their individual roles in the exacerbation of subclinical symptoms and the

The clinical perception that psychosis presents itself as "cases" in need of treatment has profoundly shaped the way the psychosis phenotype is conceptualized in the current classification systems [15]. Consequently, this has also influenced the way PLE are operationalized across various psychometric instruments (e.g., be it as psychotic "symptoms" or their attenuated equivalents) [25]. However, there is evidence indicating that the phenomenological quality of psychotic experiences may differ between healthy and clinical individuals [28, 77]. Further, it might be argued that there are experiences belonging to the PLE spectrum that may not have been sufficiently regarded in research. In this context, the novel PAGE-R questionnaire assessing "exceptional experiences" is worth mentioning, as its items are not derived from clinical symptoms but are based on reports from individuals from the general population seeking advice due to their experiences [50]. Indeed, a recent study suggested that EE in healthy individuals can be meaningfully integrated into positive-like symptomatology while potentially expanding the existing description of PLE [44]. Importantly, the PAGE-R might capture more subtle PLE that are often not considered in psychosis research, such as sleep-related perceptions [4, 20] or enriching delusion-like experiences [45, 78]. At the same time, it focuses on experiences and does not include beliefs in the paranormal that might be less relevant for the study of subclinical psychosis [31, 54]. Interestingly, factor analyses suggested the presence of three types of experiences that paralleled the basic structure of the CAPE positive dimension [48], encompassing odd beliefs (*cf*., delusional ideations), dissociative anomalous perceptions (*cf*., bizarre experiences) and hallucinatory anomalous perceptions (*cf*., perceptual anomalies). Importantly, this finding indicated that PLE basing on clinical observations and PLE basing on reports of unusual experiences by the general population might represent overlapping and complementary facets of positive psychotic symptomatology. Indeed, current research suggests that the PAGE-R might provide a more differentiated picture of PLE and new information on their associations with indicators of disadvantage and well-being as well as etiological

However, the PAGE-R was originally not created to study PLE, but a construct referred to as "exceptional experiences" (EE, see [50]). More specifically, its representativeness for PLE in healthy states might be questioned, as individuals reporting EE are characterized by diverse psychological problems [79] and the selection and design of items are substantially influenced by the underlying concept of EE. However, the PAGE-R is currently under further development (Fach, pers. comm.). Nonetheless, its use in psychosis research might be a first step in the right direction regarding a more comprehensive assessment of PLE, as the PAGE-R is not restricted to experiences derived from clinical symptoms and inquires comfort that the experiences may confer and the context in which they occurred (e.g., during meditation). Both might be important but mostly neglected factors for evaluating the clinical relevance of certain PLE. However, pursuing this "non-clinical" approach, psychosis research might tap into supposed indicators of subclinical psychopathology that might as well measure healthy and socially desired abilities. Psychosis research has tended not to differentiate between subtypes of psychotic-like experiences (PLE) and to hold a predominantly deficit-oriented perspective on them. However, studies indicate that PLE might fundamentally differ regarding their individual psychopathological significance and risk for psychosis spectrum disorders. These results require further (longitudinal) investigations aiming at the creation of an empirically founded and accurate categorization of PLE. Importantly, new instruments featuring PLE not derived from clinical symptoms including positive valence ratings might contribute to a more accurate and comprehensive description of subclinical psychosis. Ultimately, these steps might help to advance psychosis research in explaining why some individuals with PLE become ill while others do not and could contribute to more precise risk screenings and more effective therapeutic strategies in the long run.
