title: The prodromal questionnaire (PQ): preliminary validation of a self-report screening measure for prodromal and psychotic syndromes.
abstract: This study aims to establish preliminary validity of the Prodromal Questionnaire (PQ), a 92-item self-report screening measure for prodromal and psychotic symptoms. Adolescents and young adults (N = 113) referred to a prodromal psychosis research clinic completed the PQ and the Structured Interview for Prodromal Syndromes (SIPS [Miller, T.J., McGlashan, T.H., Woods, S.W., Stein, K., Driesen, N., Corcoran, C.M., Hoffman, R., Davidson, L., 1999. Symptom assessment in schizophrenic prodromal states. Psychiatric Quarterly 70(4), 273-287]), an interview with established validity for predicting future psychosis. When maximizing selection of true positive cases, scores on a subset of PQ items that assess positive symptoms predicted a concurrent prodromal or psychotic SIPS diagnosis with 90% sensitivity and 49% specificity. The PQ shows good preliminary validity in detecting individuals with an interview-diagnosed prodromal or psychotic syndrome, but it is less sensitive to the threshold between prodromal and full-blown psychosis.
authors.affiliation: Department of Psychology, University of California, Los Angeles, 1285 Franz Hall, Box 951563, Los Angeles, CA 90095-1563, USA. rloewy@ucla.edu
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Loewy
authors.forename: Carrie E
authors.initials: CE
authors.lastname: Bearden
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Johnson
authors.forename: Adrian
authors.initials: A
authors.lastname: Raine
authors.forename: Tyrone D
authors.initials: TD
authors.lastname: Cannon
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D011569:Psychiatric Status Rating Scales; D012372:ROC Curve; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis*; D012569:Schizotypal Personality Disorder / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires