Semi-structured interview for personality functioning DSM-5 (STiP-5.1): Psychometric evaluation of the Czech version

The DSM-5 Alternative Model for Personality Disorders introduced a dimensional perspective on personality disorders and their assessment by measuring personality functioning in the following domains: Identity, Self-Direction, Empathy, and Intimacy. This study provides a replication of the psychometric evaluation of the Semi-Structured Interview for Personality Functioning DSM-5 (STiP-5.1) within a mixed clinical sample and a community sample. The sample consisted of 188 adults: 86 participants from the general population and 102 people from a mixed clinical sample. All participants completed the STiP-5.1 and Level of Personality Functioning Scale-Brief Form (LPFS-BF 2.0). Results showed good internal consistency (McDonald's ω = 0.89-0.94) and promising convergent validity (correlations with LPFS-BF 2.0 above 0.6) of the STiP-5.1. Its scores differentiated participants within the community sample from those in the mixed clinical sample with large effect sizes (r_rb = 0.77-0.88). Moreover, the impairment in personality functioning was more pronounced in people with personality disorders than in other psychiatric disorders (medium effect size, r_rb = 0.46-0.57), supporting the notion of a continuum of personality functioning impairment. The STiP-5.1 therefore offers an instrument with satisfactory psychometric properties for the assessment of personality functioning both for research and clinical practice.