Linguistic markers and basic self-disturbances among adolescents at risk of psychosis. A qualitative study.

Background: Language impairments are key features of schizophrenia spectrum disorders, and have also been suggested to signal enhanced psychosis risk. Incoherence, derailment, and monotonous speaking are however closely related to psychosis onset, and thus not very early markers. Recent phenomenologic-psychiatric studies claim that basic self-disturbance (BSD) may represent more useful early markers. Methods: We searched for distinctive irregular linguistics of 30 CHR outpatient adolescents, aged 12-18 years. Standard instruments established psychosis risk and BSD. Participants chose three personal and well manifested BSD phenomena. Ninety verbatim statements were analyzed and grouped into higher order clusters of linguistic irregularities. Findings: We identified five clusters of irregular language features: distinctive words, describing an atmosphere of unreality; irregular use of prepositions, indicating experiential detachment; shifts of personal pronouns, indicating identity confusion; near-literal use of metaphors and conjunctions indicating existential insecurity, and idiosyncratic use of adjectives indicating perceptual transcendence. Interpretation: The adolescents provided naturalistic descriptions of experiences that were markedly twisted and almost ineffable. This unique irregular "BSD -language" was highly meaningful in its proper context, expressing informative characteristics of first-personal experiential alterations, essential for early detection. The features may additionally represent precursors of psychosis transition, useful for clinical decision-making. Funding: Foundation Dam, Oslo, Norway (Grant Number 2017/FO143368).