BackgroundThe Community Assessment of Psychic Experiences-Positive 15-items scale (CAPE-15) is another brief, valid screening tool used to identify people at high risk of psychosis in the community. This study examined the reliability and validity of the Korean version of the CAPE-15 in university students.MethodsThis study had two stages: initial screening with self-report questionnaires including the CAPE-15, and semi-structured interviews to investigate the instrument’s diagnostic validity. The initial screening involved 1,749 college students. The modified Korean version of Prodromal Questionnaire-16 item (mKPQ-16) was also administered. The criteria for ultra-high risk (UHR) of psychosis in the Comprehensive Assessment of At-Risk Mental States (CAARMS) were the gold standard for diagnosis.ResultsTwelve of the interviewed subjects met the CAARMS criteria for UHR of psychosis. The area under the receiver operating characteristic curve was highest (0.936) for the CAPE-15 distress score (p<0.001). The use of 6 as the cutoff for the CAPE-15 distress score resulted in the best balance of sensitivity (91.7%) and specificity (85.2%), with a favorable positive predictive value of 32.4%. The coefficients of correlation between the CAPE-15 and mKPQ-16 were significant.DiscussionThis study showed that the CAPE-15 is a good screening instrument for use in community and school settings. In particular, the better validity of the CAPE-15 suggests that it is a promising alternative to other brief self-report screening tools that are currently used to detect UHR. This validation of a questionnaire with a small number of items may make it feasible to screen large numbers of young adults in the community and shorten the duration of untreated psychosis through prompt early intervention.