A system for diagnosing personality pathology that is empirically derived, clinically relevant, and practical for day-to-day use is described. A random US sample of psychiatrists and clinical psychologists (N=1,201) described a randomly selected patient with any degree of personality dysfunction using the Shedler-Westen Assessment Procedure-II (SWAP-II). Factor analysis to identify naturally occurring diagnostic groupings yielded 10 clinically coherent personality diagnoses organized into three higher-order clusters: internalizing, externalizing, and borderline- dysregulated. The most highly rated descriptors to construct a diagnostic prototype for each personality syndrome were selected. In a second, independent sample, researchers and clinicians were able to diagnose the personality syndromes with high agreement and minimal comorbidity. These 10 prototypes provide a framework for personality diagnosis that is both empirically based and clinically relevant.
Keywords: Personality disorders, diagnosis and classification, SWAP-II, prototype diagnosis, personality styles and health

Drew Westen, Jonathan Shedler, Bekh Bradley, Jared A. DeFife, An empirically derived taxonomy for personality diagnosis: bridging science and practice in conceptualizing personality in "PSICOTERAPIA E SCIENZE UMANE" 3/2012, pp. 327-358, DOI:10.3280/PU2012-003001