Screening the community for individuals at ultra-high risk (UHR) for psychosis

Introduction: The problem of detecting people at ultra-high risk for psychosis (UHR) remains an issue. Thus, screening tools have received increased attention. We assessed the performance of the Prodromal Questionaire-16 (PQ-16) and the Perceptual and Cognitive Aberrations scale (PCA) to screen for UHR in the general population of Sao Paulo. Methods: Individuals aged 18-35 years (n=6500) were interviewed with the PQ-16 and the PCA. Those with a combined score>10 on the PQ-16+BS were called for assessment with the Structured Interview for Psychosis-Risk Syndromes (SIPS). 75 individuals were deemed as UHR and 99 as healthy comparison; 44 randomly selected individuals (PQ-16+PCA scores<10) joined as further controls. All participants had no DSM-5 diagnosis. Scores of the PCA, PQ-16 (total score and distress index), and their combinations were analyzed. Results: All the proposed scorings significantly distinguished between UHR and control subjects. PQ-16 scoring showed the best performance (AUC=0.711), followed by the PQ-16+PCA combination (AUC=0.700). PQ-16 distress index had the worst performance. Conclusions: Data provides further evidence for the use of the PQ-16 as an effective screening instrument to search for UHR states in the general population. This can help UHR identification, reduce delays in care, while minimizing the risk of false positives.