Personality disorders: the impact of severity on societal costs.

Personality disorders (PDs) are associated with high levels of societal costs. However, previous research has found limited or no evidence of unique contributions of individual PD categories on the overall level of societal costs. Recent research supports the validity of PD as a dimensional construct, and PD severity may be a better predictor of societal costs than specific PD categories. The aim of this study was to explore if PD severity could predict the level of societal costs among treatment-seeking patients with PDs, while controlling for the impact of comorbid mental health and substance use disorders. Four different severity indicators were explored: the number of PDs, the total number of PD criteria, the number of BPD criteria, and the Level of Personality Functioning Scale (LPFS) from the alternative model in DSM-5. Participants (n = 798/794) were retrieved from the quality register of the Norwegian Network for Personality Disorders for the period 2017-2020. Societal costs were assessed using a structured interview covering the six-month period prior to assessment. Diagnoses and diagnostic criteria were determined using a semi-structured diagnostic interview (SCID-5-PD and M.I.N.I), and the LPFS was assessed by the LPFS-Brief Form 2.0 (LPFS-BF 2.0) questionnaire. Statistics included multiple regression analyses. None of the severity indicators were significant predictors of overall societal costs among treatment-seeking patients, and effect sizes were small.