Changes in the level of personality functioning in inpatient psychotherapy.

Background: The model of Operationalized Psychodynamic Diagnosis and the model of Personality Organization influenced the concept of the Level of Personality Functioning (LPF) in DSM-V. The LPF is becoming a key variable for diagnostics, treatment and outcome measurement, but there are few studies which integrate the LPF in the study design. This study pursues to expand this body of knowledge by investigating the research question: would an inpatient psychotherapy lead to significant improvements in the LPF? Methods: The study included 156 inpatients at the Psychiatric Hospital Münsterlingen, Switzerland. Exclusion criteria were aggression, psychosis, mental retardation, and participation in another study. The LPF was measured with the Operationalized Psychodynamic Diagnosis-Structure Questionnaire (OPD-SQ) and the short version of the Inventory of Personality Organization (IPO-16) at admission and termination of treatment about eleven weeks later. A repeated-measures ANOVA controlled for age, symptom load, treatment duration and gender was conducted. Results: Data revealed significant, medium improvements for OPD-SQ ( F (2,88) = 8.24, p  < .01, η p 2  = 0.09) and IPO-16 ( F (2,91) = 6.09, p  < .05, η p 2  = 0.06) between admission and termination of psychotherapy and a different change pattern for OPD-SQ and IPO-16. Conclusion: Inpatient psychotherapy is associated with improvements in LPF.