Results of the Search for Personality Disorder Screening Tools

Abstract

To examine the characteristics, validity, posttest probabilities, and screening capabilities of 8 different instruments used to predict personality disorders. Screening instruments were examined in 3 prospective, observational, test-development studies in 3 random samples of Dutch psychiatric outpatients, using the Structured Clinical Interview for DSM-IV Axis II Disorders (SCID-II) as the "gold standard." The studies were performed from March 2004 to March 2005 (study 1: N = 195, mean age = 32.7 years), October 2006 to January 2007 (study 2: N = 79, mean age = 34.3 years), and January 2008 to October 2009 (study 3: N = 102, mean age = 33.7 years). The following 8 assessment instruments were examined: 3 short questionnaires (a self-report form of the Standardized Assessment of Personality-Abbreviated Scale [SAPAS-SR], the self-report Iowa Personality Disorder Screen [IPDS], and a short self-report version of the SCID-II [S-SCID-II]); 2 longer questionnaires (the self-report SCID-II Personality Questionnaire [SCID-II-PQ] and the NEO Five-Factor Inventory [NEO-FFI]); 1 short semistructured interview (the Quick Personality Assessment Schedule [PAS-Q]); and 2 informant-based interviews (the Standardized Assessment of Personality [SAP] and the Standardized Assessment of Personality-Abbreviated Scale for Informants [SAPAS-INF]). The SCID-II rate of identification of personality disorders in the 3 studies was between 48.1% and 64.1%. The SAPAS-SR, the IPDS, and the PAS-Q had the best sensitivity (83%, 77%, and 80%, respectively) and specificity (80%, 85%, and 82%, respectively). Moreover, these 3 instruments correctly classified the largest number of patients. Using the SAPAS-SR, the IPDS, or the PAS-Q raises the odds from 50% to between 80% and 84% that a patient in a psychiatric outpatient population will receive a personality disorder diagnosis. The results provide evidence for the usefulness of the SAPAS-SR, IPDS, and PAS-Q instruments for personality disorder screening. Because the PAS-Q takes a longer time and requires qualified personnel to administer it, we recommend use of the SAPAS-SR or the self-report version of the IPDS.