Mentalization-oriented psychodynamic group therapy for patients with personality disorders: a naturalistic prospective cohort study

Abstract

Objectives

Patients with personality disorders (PDs) are often treated with non-manualized psychodynamic group therapy (PDT) lasting for several years. Non-manualized PDT often combines a variety of therapeutic approaches from different PDT traditions, including mentalization-based therapy. Currently, little is known about the effect of this long-term, costly treatment. This study investigated the extent to which patients with different PDs benefit from mentalization-oriented PDT as it is implemented in clinical practice in terms of symptom severity, interpersonal problems, and general functioning.

Methods

The design was a naturalistic, prospective cohort study. Seventy-five consecutive PD patients were assessed before treatment with the Symptom Checklist-90 Revised (SCL-90-R) as the primary outcome measure and the Inventory of Interpersonal Problems (IIP) and Global Assessment of Functioning (GAF) as secondary outcome measures. The sample was repeatedly assessed every 12 months for up to 36 months. Paired t-tests were applied to examine the effectiveness of the intervention.

Results

Among completers (n = 42; 56%), improvement was observed on the SCL-90-R: Global Severity Index (mean change = −0.45 [95% CI = –0.72, −0.19]; Cohen’s d = –0.55), Positive Symptom Distress Index (–0.40 [–0.63, −0.17]; −0.56); Positive Symptoms Total (–10.70 [–17.31, −4.09]; −0.52). Secondary outcomes also improved: IIP-total (mean change = –0.50 [95%CI = –0.74, −0.25]; Cohen’s d = –0.66); GAF-Functioning (8.79 [6.32, 11.27]; 1.15); and GAF-Symptoms (10.67 [8.09, 13.25]; 1.34).

Conclusions

Completers improved on symptom severity, interpersonal problems, and general functioning, with within-group effect sizes ranging from medium to large. Approximately half the sample dropped out, suggesting that mentalization-oriented PDT spanning several years may be unrealistic for many patients with PD.

Significant outcomes

• There are no clear guidelines for psychological interventions targeting personality disorders (PDs), and currently eclectic and non-manualized psychodynamic approaches lasting for up to 3 years are prevailing in some clinical practices.

• Although this treatment approach may have an effect on compliant patients, the high drop-out rate indicates that it may not be suitable for a large proportion of PD patients since it requires long-term commitment. Furthermore, it is difficult to identify the content of the non-manualized psychodynamic therapy and what helps the patients.

• More specific clinical guidelines emphasizing the application of evidence-based treatments or at least manualized treatments are warranted for the treatment of emotionally unstable PDs and other PDs.

Limitations

• The naturalistic study design, without any control group, limits conclusions about mechanisms of action of the intervention.

• Since the intervention was not manualized, it is unknown exactly which treatment was actually administered, which reduces external validity.

• The outcomes are based on completer data of a relatively small sample size with high drop-out rate.

Keywords:

• Clinical practice
• mentalization
• personality disorders
• psychodynamic therapy
• group therapy

Acknowledgments

The project was unconditionally funded by the Psychiatric Research Foundation of Southern Denmark.

Author contributions

BAS, ES, JB and AIM designed the study and got it funded. JB, PVL, BAS, CS, and AIM retrieved, managed, and analyzed the data. BAS, LS, and AIM wrote the draft of the manuscript, and all authors contributed to and approved the final manuscript.

Notes on contributors

Bo Anton Svensson is MD in training to become a specialist in psychiatry at the Psychiatric Clinic in Lund, Sweden. He has previously been employed as a research assistant in psychiatry in the Region of Southern Denmark.

Jacob Bredtoft is Cand. Psych. and authorized psychologist. He has been employed in Group Therapeutic Team for Personality Disorders since 2014, working as a group therapist, supervisor, researcher and educator.

Elsebeth Stenager, MD, consultant, is professor in Social psychiatry at the University of Southern Denmark. Her research interest is in particular suicide research, epidemiology, and studies concerning somatic problems in psychiatric patients. Clinically, she has for many years worked as a consultant with special interest in patients with personality disorders.

Pia Veldt Larsen is statistical consultant at the Mental Health Services in the Region of Southern Denmark. She provides statistical support to researchers in psychiatry in the Region of Southern Denmark.

Lotte Skøt has a master’s degree in Psychology from the University of Copenhagen. She completed her PhD in Health Sciences, in 2020, at the University of Southern Denmark. She is currently working as a research assistant at the Unit for Clinical Alcohol Research, University of Southern Denmark.

Christian Sibbersen, PhD, is a statistician and data scientist with a background in chemistry from Aarhus University, Denmark. He is currently working in the field of chemometrics.

Angelina Isabella Mellentin is clinical licensed psychologist and associated professor at the Unit of Psychiatric Research, Department of Psychiatry, Odense, Denmark. She has mainly worked with patients with alcohol and other substance use disorders (SUDs), but also a range of other psychiatric disorders without co-existing SUDs, including personality disorders and eating disorders.

Disclosure statement

The authors have no conflicts of interest to disclose.

Data availability statement

The dataset for this study will be made available upon request from the authors, provided that this complies with national legislation and the decisions of the ethical committee.