Background The treatment of patients diagnosed with a narcissistic personality disorder (NPS) is considered to be extra challenging. Well-controlled studies on the effectiveness of psychotherapy in NPS patients are not available; so many interventions are based on theoretical constructs. The clarification-oriented psychotherapy (COP) is a psychotherapeutic approach, which emerged from concepts of the cognitive behavioral therapy, client-centered psychotherapy and various process-oriented procedures. The present ambulatory therapy-evaluation of COP aimed to evaluate the effectiveness of a psychotherapeutic treatment for patients suffering from NPS.
Methods and Results Retrospective cohort-study including 173 treatment-seeking NPS-patients. Via pre-post per-protocol-analysis, significant improvements mostly with medium effect sizes were found in all relevant parameters after completion of the COP (58.6±10.5 sessions). In particular, the ambitious/narcissistic personality style in the Personality Style and Disorders Inventory (PSSI) (primary outcome) was improved (medium effect size: d = −0.49 [−0.67; −0.31], p < 0.001). Analyses revealed even high effect sizes in terms of the improvement of depressive states and traits, neuroticism as well as self-acceptance. The lowest effect sizes however were found for improvements in self-regulation (d = 0.2 [0.03; 0.36], p = 0.02).
Discussion As no intention-to-treat analysis has been carried out, the effect sizes of COP in the treatment of NPS might be overestimated. Nevertheless, our findings support the use of COP for the treatment of NPS. In light of evidence-based medicine, the present so far most comprehensive study on this topic warranted an increase of the evidence of COP in the treatment of NPS from level IV to level III.