A Common Metric for Self-Reported Severity of Personality Disorder

Abstract

Introduction: Dimensional models of personality disorders (PD) in the DSM-5 and ICD-11 share a focus on impairments in self and interpersonal functioning to represent the general features and severity of PD. This new perspective has led to the development of numerous measures for assessing individual differences in PD severity. While this improves choices for researchers and practitioners, it also poses the challenge of an increasing lack of standardization. Objective: The aim of this study is to establish a common metric across 6 widely used self-report measures of PD severity using item response theory models. Methods: 849 participants completed a survey including the Inventory of Personality Organization-16-item version (IPO-16), the Level of Personality Functioning Scale-Brief Form 2.0, the Level of Personality Functioning Scale-Self-Report, the Operationalized Psychodynamic Diagnosis-Structure Questionnaire Short Form, the Personality Inventory for DSM-5-Brief Form Plus and the Standardized Assessment of Severity of Personality Disorder (SASPD). We fitted exploratory multidimensional graded response models and used bifactor rotation to extract a general factor across measures. Factor scores were linked to representative T scores using data from a representative survey of 2,502 participants who completed the IPO-16. Results: When using bifactor rotation in a 7-factor model, all items loaded positively on the general factor, and the general factor explained 65.5% of the common variance. With the exception of the SASPD, all measures provided highly discriminating items (factor loadings > 0.70) for measuring the general factor and reached an acceptable reliability (> 0.80) across a wide range of the latent continuum. We constructed a crosswalk table linking total scores of the 6 measures to each other and to representative T scores. Conclusions: Our results suggest that 6 different self-report measures of the severity of PD capture a strong common factor and can therefore be scaled along a single latent continuum. Our results may facilitate instrument-independent assessment of severity of PD and increase comparability across studies.

ICD-11 Personality Disorders: A Psychodynamic Perspective on Personality Functioning

“…From a psychodynamic viewpoint, the inclusion of severity of impairment as the core feature of personality disorder classification represents a major improvement over previous classification systems. Multiple studies have confirmed global severity as the single most important predictor for current and future dysfunction (37)(38)(39). The consideration of the severity of personality pathology also has been a central component of psychodynamic approaches to personality pathology for decades.…”

“…But the results also show that the SASPD predominantly captures externalizing, interpersonal difficulties, while somewhat neglecting the area of self-functioning and internal distress. Additionally, Zimmermann et al (39) raised concern about the reliability of the SASPD to measure personality pathology severity when compared to 5 other self-report instruments derived from DSM-5 (LPFS-Brief Form 2.0, LPFS-Self Report, Personality Inventory for DSM-5-Brief Form Plus) and the psychodynamic tradition (IPO-16, OPD-SQS), arguably equally due to its lack of incorporation of items assessing the selfrelated dimension of personality functioning. Accordingly, the authors found a stronger correlation between the psychodynamic instruments and the AMPD of DSM-5 than with the ICD-11 system (39).…”

“…Additionally, Zimmermann et al (39) raised concern about the reliability of the SASPD to measure personality pathology severity when compared to 5 other self-report instruments derived from DSM-5 (LPFS-Brief Form 2.0, LPFS-Self Report, Personality Inventory for DSM-5-Brief Form Plus) and the psychodynamic tradition (IPO-16, OPD-SQS), arguably equally due to its lack of incorporation of items assessing the selfrelated dimension of personality functioning. Accordingly, the authors found a stronger correlation between the psychodynamic instruments and the AMPD of DSM-5 than with the ICD-11 system (39). Similar results were provided by Oltmanns and Widiger, who found a significantly higher correlation between the IPO and LPFS than between these two and the SASPD (41).…”

Inventário de Organização da Personalidade – Brasil: evidências de validade baseadas em critérios externos

“…Um grave transtorno da personalidade tem sido determinado por prejuízos severos na constituição do self, com problemas na integração da identidade e no autogoverno, bem como por prejuízos graves nos estilos de relacionamento interpessoal, com problemas na empatia e intimidade. Esses novos modelos estão intrinsecamente alinhados com o modelo de OP de Kernberg [22][23][24] . De fato, um estudo inclusive encontrou itens no IPO que cobrem todos os construtos do modelo alternativo de diagnóstico dos transtornos da personalidade descritos no DSM-5 1 .…”

The Utility of ICD-11 and DSM-5 Traits for Differentiating Patients With Personality Disorders From Other Clinical Groups

“…The current study sought to investigate the utility of the PID5BF+M total score along with specific domain and facet scores in differentiating patients with PDs from other psychiatric patients. The use of the PID5BF+ as a proxy of severity is particularly supported in a comparative study by Zimmermann et al (22), which found the total PID5BF+ score to align well with a number of PD severity measures.…”