Investigating the validity and measurement invariance of the Personality Inventory for DSM-5 Faceted Brief Form among French-speaking clinical and nonclinical samples

There has been no proper validation of the Personality Inventory for the Diagnostic and Statistical Manual of Mental Disorders (PID-5) Faceted Brief Form (PID-5-FBF), a shortened 100-item version of the original PID-5, in the French language. In addition, more than one domain scoring procedure has been proposed in the literature, and no study has attempted to compare them from a factor analytic standpoint. Also, no study about the PID-5 (nor the PID-5-FBF) has been conducted with private practice clients, to the best of our knowledge, despite the fact that it is a very common clientele. This study seeks to (a) provide initial evidence of reliability and validity for the PID-5-FBF among French-speaking samples; (b) compare the structure of the PID-5-FBF while using two different domain scoring procedures; and (c) investigate its measurement invariance between sexes and across samples following a theoretical gradient of psychopathology. Indices of reliability and validity were documented among three samples: a community sample (n = 526, 49.8% women), private practice clients (n = 544, 64.0% women), and outpatients with personality disorder (n = 288, 61.5% women). Results generally showed good to excellent psychometric properties, providing initial support for the PID-5-FBF for research and clinical applications. The results of both scoring procedures were good, but one showed a clear advantage, by having notably cleaner loadings. Using stringent criteria, strict invariance was supported between sexes, while partial invariance was supported across samples. Clinical implications are discussed, notably pertaining to private practice clients, an understudied group