Differences in personality functioning impairment in mood, anxiety, and personality disorders: a cluster analysis.

Background: The Alternative DSM-5 Model for Personality Disorders and the latest eleventh version of the International Classification of Diseases implement the level of impairment in self and interpersonal personality functioning (Level of Personality Functioning Scale - LPFS) as a core feature of personality pathology. However, some studies have indicated that personality functioning is also impaired in other mental disorders, but a more thorough exploration is missing. Thus, this study aims to develop profiles of levels of personality functioning in people with personality disorders and some other psychiatric diagnoses as well as without diagnosis.

Methods: One-hundred-forty-nine people participated in the study. They came from three groups - healthy controls (n = 53), people with personality disorders (n = 58), and people with mood and anxiety disorders (n = 38). The LPFS was assessed by the Semi-structured Interview for Personality Functioning DSM-5 (STiP-5.1). An optimal clustering solution using agglomerative hierarchical cluster analysis was generated to represent profiles of personality functioning.

Results: The two patient groups showed significantly higher levels of personality functioning impairment than healthy controls. People with personality disorders showed higher levels of impairment than the other groups. In addition, the clustering analysis revealed three distinct profiles of personality functioning.

Conclusions: The impairment of personality functioning seems to be useful in the clinical assessment of other than personality disorders as well. As the resulting clustering profiles suggest, LPFS can be seen as an overall indicator of the severity of mental health difficulties and the presence of mental disorders symptoms. The LPFS provides valuable and detailed information about the individual's mental health and can thus serve as a broad basis for case formulation, treatment and therapy planning, and prognosis.