Psychoanalytic-Interactional Therapy versus Psychodynamic Therapy by Experts for Personality Disorders: A Randomized Controlled Efficacy-Effectiveness Study in Cluster B Personality Disorders

Abstract

Background: With regard to cluster B personality disorders, most psychotherapeutic treatments focus on borderline personality disorder. Evidence-based treatments for patients with other cluster B personality disorders are not yet available. Psychoanalytic-interactional therapy (PIT) represents a transdiagnostic treatment for severe personality disorders. PIT has been applied in clinical practice for many years and has proven effective in open studies. In a randomized controlled trial, we compared manual-guided PIT to nonmanualized pychodynamic therapy by experts in personality disorders (E-PDT) in patients with cluster B personality disorders. Methods: In an inpatient setting, patients with cluster B personality disorders were randomly assigned to manual-guided PIT (n = 64) or nonmanualized E-PDT (n = 58). In addition, a quasi-experimental control condition was used (n = 46) including both patients receiving treatment as usual and patients waiting for treatment. Primary outcomes were level of personality organization and overall psychological distress. As secondary outcomes, depression, anxiety and interpersonal problems were examined. Results: No significant improvements were found in the control patients. Both PIT and E-PDT achieved significant improvements in all outcome measures and were superior to the control condition. No differences were found between PIT and E-PDT in any outcome measure at the end of treatment. The type of cluster B personality disorder had no impact on the results. Conclusions: In an inpatient setting, both PIT and E-PDT proved to be superior to a control condition in cluster B personality disorders. In a head-to-head comparison, both treatments appeared to be equally effective. Further research on the treatment of cluster B personality disorders is required.