Validation of the Korean Version of the Prodromal Questionnaire-Brief Version in Non-Help-Seeking Individuals

OBJECTIVE: In this study, we examined the reliability and validity of the Korean version of the Prodromal Questionnaire-Brief (PQ-B), a self-report screening instrument for clinical high risk for psychosis (CHR). METHODS: A total of 3,400 middle, high school and college students participated, and 261 subjects with a PQ-B total score ≥3 completed both the PQ-B and the Structured Interview for Prodromal Syndromes (SIPS). Receiver operating characteristic (ROC) curves were used to examine the psychometric properties of the PQ-B. RESULTS: A cut-off of 7 for the PQ-B total score and a cut-off of 22 for the PQ-B distress score showed the best balance of sensitivity (72.2%, 77.8%) and specificity (71.4%, 75.0%). CONCLUSION: The Korean version of the PQ-B showed good reliability and validity for predicting prodromal risk symptoms in the community population.