Abstract / Summary
Background. Something in discourse with a person experiencing psychosis often "feels off" before formal assessment is completed, yet this phenomenon has not been quantified at the level of ongoing dyadic conversation. Prior work has largely treated patient speech in isolation, limiting our capacity to measure how communicative disruption emerges within clinical exchange. Methods. We applied a three-level decomposition of conversational alignment in 109 patients with psychotic disorders (26 female) and 60 healthy controls (22 female) at baseline and 12 months (n = 115). Register divergence captured lexical distance between interviewer and participant; embedding-based synchrony measured semantic trajectory coupling; within-speaker coherence was computed separately for each speaker. We used linear mixed-effects models adjusted for timepoint and participant clustering. Results. Patients showed significantly greater lexical-semantic divergence from the interviewer (d = 0.48, p < .001) and reduced embedding-based synchrony (d = -0.59, p < .001), both effects observed at each timepoint, consistent with a partially stable profile. Critically, the interviewer's within-speaker coherence was reduced during conversations with patients (d = -0.33, p = .016), indicating that the linguistic phenomenon of interest extended beyond patient speech to the interaction itself. Register divergence tracked impoverished thinking, while synchrony tracked disorganized thinking (both FDR-corrected q = .038). Conclusions. Conversational alignment in psychosis reveals a reconfiguration of dyadic semantic coordination, marked by reduced interviewer coherence despite preserved patient narrative continuity. These transcript-derived alignment metrics offer a scalable approach to quantifying interpersonal communicative function in routine clinical encounters.