Diagnostic and Prognostic Significance of DSM-5 Attenuated Psychosis Syndrome in Services for Individuals at Ultra High Risk for Psychosis.

Background: The diagnostic and prognostic significance of the DSM-5-defined Attenuated Psychosis Syndrome (DSM-5-APS) in individuals undergoing an ultra high risk (UHR) clinical assessment for suspicion of psychosis risk is unknown. Methods: Prospective cohort study including all consecutive help-seeking individuals undergoing both a DSM-5-APS and a Comprehensive Assessment of At Risk Mental States (CAARMS 12/2006) assessment for psychosis risk at the Outreach and Support in South London (OASIS) UHR service (March 2013-April 2014). The diagnostic significance of DSM-5-APS was assessed with percent overall agreement, prevalence bias adjusted kappa, Bowker's test, Stuart-Maxwell test, residual analysis; the prognostic significance with Cox regression, Kaplan-Meier failure function, time-dependent area under the curve (AUC) and net benefits analysis. The impact of specific revisions of the DSM-5-APS was further tested. Result: In 203 help-seeking individuals undergoing UHR assessment, the agreement between the DSM-5-APS and the CAARMS 12/2006 was only moderate (kappa 0.59). Among 142 nonpsychotic cases, those meeting DSM-5-APS criteria had a 5-fold probability (HR = 5.379) of developing psychosis compared to those not meeting DSM-5-APS criteria, with a 21-month cumulative risk of psychosis of 28.17% vs 6.49%, respectively. The DSM-5-APS prognostic accuracy was acceptable (AUC 0.76 at 24 months) and similar to the CAARMS 12/2006. The DSM-5-APS designation may be clinically useful to guide the provision of indicated interventions within a 7%-35% (2-year) range of psychosis risk. The removal of the criterion E or C of the DSM-5-APS may improve its prognostic performance and transdiagnostic value. Conclusions: The DSM-5-APS designation may be clinically useful in individuals accessing clinical services for psychosis prevention.