More Is More: Evidence for the Incremental Value of the SCID-II/SCID-5- PD Specific Factors Over and Above a General Personality Disorder Factor

Abstract

Currently, 3 competing conceptualizations of personality dysfunction can be distinguished: the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM–5) categorical model delineating 10 distinct types of personality disorders (PDs); the alternative model for PDs (DSM–5 Section III), which assesses personality functioning and traits separately; and the International Classification of Diseases, 11th Version conceptualization, which provides 1 single code for the presence of a PD (which is based on problems in functioning) as well as codes that specify the level of the disorder (mild/moderate/severe), and prominent trait domains or patterns (5 domains and 1 pattern). The current study aims to assess the incremental value of the DSM–5 PDs over and above a global personality dysfunction factor, using expert ratings obtained with the Structured Clinical Interview for DSM–IV PDs and the Structured Clinical Interview for DSM–5 PDs interview in a large sample of clinical patients (N = 3,851). All estimated bifactor models provided adequate fit to the data. We found a surprisingly low explained common variance for the g-factor (<40%), indicating that ignoring the specific PD factors would lead to a substantial loss of information. The strongest specific PDs in terms of explained common variance were the avoidant, schizotypal, and schizoid PD factors and the conduct disorder criteria set if included. Correlations between our factors and external variables were relatively low, except for the Severity Indices of Personality Problems, which aims to measure personality functioning. Our findings suggest that specific PDs still have an important role to play in the assessment of personality pathology.