The Personality Disorder Severity ICD-11 (PDS-ICD-11) Scale: Psychometric Properties and Incremental Predictive Validity for Trait Domains in Czech Community and Treatment-Seeking Groups.

The 11th revision of the International Classification of Diseases defines the severity of dysfunction as a core diagnostic criterion for personality disorders. This study examined the psychometric properties of the Czech adaptation of the Personality Disorder Severity-ICD-11 (PDS-ICD-11) scale. The sample consisted of 1704 participants (72.4% women) in community (n = 612) and treatment-seeking (n = 1092) groups. Results supported the unidimensionality of the PDS-ICD-11, good internal consistency, and expected associations with a validated measure of severity (Levels of Personality Function Scale-Brief Form 2.0; LPFS-BF 2.0), as well as with pathological traits and quality of life measures. Compared with the LPFS-BF 2.0, the PDS-ICD-11 demonstrated stronger associations with quality of life (small effect size) and was a better predictor of treatment-seeking status; however, it explained less variance in pathological traits, except for negative affectivity. Neither severity measure showed a balanced representation of trait domains, suggesting a need for refinement. Overall, the Czech PDS-ICD-11 offers a valid and efficient tool for screening the severity of personality dysfunction, with utility in both research and clinical settings.