The Mini Version of the Level of Personality Functioning Scale-Brief Form (Mini-LPFS): Development and Validation in Two Clinical Samples

This study developed and validated a mini (4-item) version of the Level of Personality Functioning Scale-Brief Form 2.0 (LPFS-BF 2.0) to assess personality functioning as defined in the DSM-5 Alternative Model for Personality Disorders. Two samples were used: a U.S. clinical sample (<i>N</i> = 700) and a Dutch mixed clinical sample (<i>N</i> = 298). In the U.S. sample, participants completed the LPFS-BF 2.0, the Big Five Inventory-2-Extra-Short Form, and several mental health measures. Item combinations that spanned each of the four LPFS elements were evaluated using confirmatory factor analyses and graded response item response theory models to select a promising set in a U.S. sub-sample (<i>n</i> = 350), and this set was evaluated in a second U.S. sub-sample (<i>n</i> = 350). The Dutch sample was used both to validate the scale and to examine cross-cultural measurement invariance. Confirmatory factor analyses supported a one-factor representation of the four-item set in both samples. The Mini-LPFS demonstrated strong convergence with the original LPFS-BF 2.0, satisfactory internal consistency, promising validity, and cross-cultural generalizability. These findings support the Mini-LPFS as an efficient, low-burden measure of overall personality functioning in research settings and as a candidate tool for screening and monitoring, with clinical applications contingent on further evidence.