The effect of comorbid personality disorder on depression outcome after short-term psychotherapy in a randomised clinical trial

David Koppers; Marit Kool; Henricus Van; Ellen Driessen; Jaap Peen; Jack Dekker

doi:10.1192/bjo.2019.47

The effect of comorbid personality disorder on depression outcome after short-term psychotherapy in a randomised clinical trial

BJPsych Open. 2019 Jul 16;5(4):e61. doi: 10.1192/bjo.2019.47.

Authors

David Koppers¹, Marit Kool², Henricus Van³, Ellen Driessen⁴, Jaap Peen⁵, Jack Dekker⁶

Affiliations

¹ Clinical Psychologist and Researcher, Department of Research and Quality of Care, ARKIN Mental Health Institute, the Netherlands.
² Clinical Psychologist and Researcher, Department of Personality Disorders, ARKIN Mental Health Institute, the Netherlands.
³ Psychiatrist, and Researcher, Department of Personality Disorders, ARKIN Mental Health Institute, NPI, the Netherlands.
⁴ Researcher, Department of Research and Quality of Care, ARKIN Mental Health Institute, the Netherlands.
⁵ Methodologist, Department of Research and Quality of Care, ARKIN Mental Health Institute, the Netherlands.
⁶ Head, Department of Research and Quality of Care, ARKIN Mental Health Institute; and Faculty of Behavioural and Movement Sciences, Section Clinical Psychology, Vrije Universiteit, the Netherlands.

Abstract

Background: Time-limited psychotherapy for depression is effective. However, comorbid personality disorders affect therapy outcomes negatively. Studies of follow-up effects and results relating to the influence of comorbid personality disorder and treatment modality are scarce.

Aims: To determine the influence of comorbid personality disorder and treatment modality on outcomes after cognitive-behavioural therapy (CBT) or short-term psychodynamic supportive psychotherapy (SPSP) for depression.

Method: This study draws on data from a previously published randomised clinical trial contrasting SPSP and CBT for depression (both 16 sessions). We compared the effectiveness of these psychotherapies for patients with and without personality disorder (n = 196). The primary measure was depression outcome; the secondary measurements were interpersonal functioning and quality of life. Collected data were analysed using multilevel analysis. Trial registration: ISRCTN31263312 (http://www.controlled-trials.com).

Results: Although participants with and without comorbid personality disorder improved at treatment termination (d = 1.04, 95% CI 0.77-1.31 and d = 1.36, 95% CI 0.97-1.76, respectively) and at follow-up (d = 1.15, 95% CI 0.87-1.43 and d = 2.12, 95% CI 1.65-2.59 respectively), personality disorder had a negative effect on depression outcome at both measurement points (P < 0.05). A similar negative effect on interpersonal functioning was no longer apparent at follow-up. Comorbid personality disorder had no influence on social functioning or quality of life outcomes, irrespective of treatment modality.

Conclusions: CBT and SPSP contribute to the improvement of depressive symptoms and interpersonal problems in depressed patients with and without comorbid personality disorder. Both treatments are an effective first step in a stepped care approach, but - given remaining levels of depression in patients with personality disorder - they are probably inadequate for large numbers of patients with this comorbidity.

Declaration of interest: None.

Keywords: Comorbidity; depressive disorders; outcome studies; personality disorders; randomised controlled trial.