The role of treatment duration in psychodynamic group therapy: A randomized clinical trial of short-term and long-term Group Analytic Psychotherapy

Abstract

The efficacy of group psychotherapy for a wide variety of different mental disorders has been clearly demonstrated. However, it remains unclear how long therapy must last for change to take place. The aim of my thesis is to generate knowledge on the differential effectiveness of short- and long-term group analytic psychotherapy for psychiatric outpatients. We also wanted to investigate how presence of personality disorder (PD) impacts the long-term outcomes of group psychotherapy of different durations. Within the field of psychodynamic group therapy, our study is the first randomized trial investigating the impact of treatment duration.

The short-term group therapy lasted 6 months (20 sessions) and long-term group therapy lasting two years (80 sessions). Patients improved in both interpersonal problems and self-relatedness in both short-term and long-term group therapy across 3 years. Patients treated in the short-term format even seemed to change earlier on problems being too distant and socially avoidant in relationships to others. With regard to change in the patients’ relationship towards themselves, patients in long-term therapy were more likely to modify their negative attitudes towards themselves compared to patients in the short-term therapy over the first 3 years.

Patients with PD had greater improvement of both symptom distress and interpersonal problems up to 7 years after the start of long-term compared to short-term therapy. There was a delayed effect after long-term therapy, while the change was sustained after short-term therapy. Patients without PD seem to have no further improvement after the first 6 months in either treatment format.

Many patients without PD are likely to be sufficiently helped by short-term group therapy, while most patients with PD will require longer therapies to improve. The study demonstrates that presence of PD may be a selection criterion for deciding therapy duration in group psychotherapy.