Assessing Psychosis Risk with the PQ-16: A Systematic Review

The identification of individuals at clinical high risk for psychosis (CHR-P) and the prediction of clinical outcomes is an important concept in early intervention (Fusar-Poli et al., 2012). Self-report instruments have been designed to facilitate detection of CHR-P individuals, such as the Prodromal Questionnaire (PQ; Loewy et al., 2005) a 92-item instrument that covers positive, negative, disorganized, and general symptom domains. More recently, Ising et al. (2012) developed a 16-item version of the PQ (PQ-16), which may be suitable for screening large populations in both help-seeking and non–help-seeking contexts. Currently, no systematic review has examined the diagnostic and prognostic accuracy of the PQ-16 in CHR-P populations. The aim of this systematic review is to examine the diagnostic and prognostic accuracy of the PQ-16, including sensitivity, specificity, and the prediction of clinical outcomes such as transition to psychosis, in CHR-Ps across different populations and settings. These settings include help-seeking individuals in early detection services, individuals in secondary mental health care, and individuals from primary care or the general population.