Addressing the elephant in the screening room: an item response theory analysis of the Prodromal Questionnaire for at-risk symptoms of psychosis.

OBJECTIVE

Patients at risk of psychosis present a variety of symptoms, and identifying the most discriminative symptoms is essential for efficient detection and treatment.

METHODS

This cross-sectional online study analyzed individuals from the general population to better assess their risk of symptoms classified as clinical high risk (CHR) for psychosis. The 16-item Prodromal Questionnaire was applied as a self-report screening tool. Item response theory with a graded response model was used to assess the discrimination and difficulty of the questionnaire's criteria.

RESULTS

The analysis included 936 participants (mean age: 21.5 years; 71.9% women). "Déjà vu" stood out for its high discriminative power, while the "voices or whispers" and "seeing things" items had greater precision than the other CHR-related symptoms. Conversely, the "smell or taste" and "changing faces" items were associated with the most severe cases.

CONCLUSION

This study identified the most indicative CHR-related symptoms for accurate assessment of psychosis severity, which can be used to guide targeted preventative interventions.