Auditory and visual oddball stimulus processing deficits in clinical high risk for psychosis: Forecasting psychosis...

Individuals at clinical high risk (CHR) for psychosis exhibit reduced P300 responses, particularly in auditory tasks. While N200 abnormalities have been reported in CHR individuals, findings are inconsistent, and research on visual oddball tasks is limited. This study compares event-related potentials (ERPs) in auditory and visual oddball paradigms between CHR individuals and healthy controls (HC), aiming to explore these components as potential biomarkers for CHR and its clinical outcomes.

Baseline auditory and visual oddball N200 and P300 were obtained from CHR participants (N = 96) and HC participants (N = 60). All CHR participants were followed up for five years and stratified into CHR converters and non-converters. The differences in N200 and P300 amplitude in auditory and visual oddball tasks were compared between the clinical outcome subgroups and HC participants. Prediction models were developed using Cox proportional hazards regression to identify baseline predictors.

CHR converters showed significantly reduced N200 and P300 amplitudes in both oddball paradigms relative to CHR non-converters and HC participants. Furthermore, Prediction models including visual N200 amplitudes (β = -0.233, p = 0.012) and auditory P300 amplitudes (β = 0.219, p = 0.039) demonstrated effective discrimination between CHR converters and non-converters.

These results suggest that N200 and P300 amplitude deficits across auditory and visual modalities precede the onset of full psychosis. Moreover, the combined assessment of visual N200 and auditory P300 amplitudes may serve as a more sensitive prognostic biomarker for predicting clinical outcomes in individuals at clinical high risk.