The Ghent Psychotherapy Study: A Pragmatic, Stratified, Randomized Parallel Trial into the Differential Efficacy of Psychodynamic and Cognitive-Behavioral Interventions in Dependent and Self-Critical Depressive Patients.

INTRODUCTION: Different types of psychotherapy are effective for treating major depressive disorder across groups yet show large within-group differences. Patient personality style is considered a potentially useful variable for treatment matching. OBJECTIVE: This study is the first experimental test of the interaction between therapeutic approach and patients' dependent versus self-critical personality styles. METHODS: A pragmatic stratified parallel trial was carried out with 100 adult patients diagnosed with DSM-IV-TR major depressive disorder. They were randomly assigned to short-term (16-20 sessions) cognitive behavioral therapy (CBT) or short-term psychodynamic psychotherapy (STPP). Patients were assessed at baseline, during therapy, post-therapy, and at 3- and 6-month follow-up. Primary outcome is depression severity measured by the Hamilton Rating Scale for Depression posttreatment. Primary analysis was by intention to treat. This trial is registered with the ISRCTN registry (www.isrctn.com), number ISRCTN17130982. RESULTS: The intention-to-treat sample consisted of 100 participants; 40 with self-critical and 60 with dependent personality styles were randomized to either CBT (n = 50) or STPP (n = 50). We observed no interaction effect (-0.34 [-6.14, 5.46]) between therapy and personality style and found no evidence for a difference in effectiveness between the treatments in general in terms of symptom reduction and maintained benefits at 6-month follow-up. CONCLUSION: We found no evidence that dependent versus self-critical personality styles moderate the relation between treatment and outcome in depression. Research using individual patient data could gain further insight into why specific therapeutic approaches work better for specific patients.

The Ghent Psychotherapy Study (GPS) on the differential efficacy of supportive-expressive and cognitive behavioral interventions in dependent and self-critical depressive patients: study protocol for a randomized controlled trial.

BACKGROUND: Major depressive disorder is a leading cause of disease burden worldwide, indicating the importance of effective therapies. Outcome studies have shown overall efficacy of different types of psychotherapy across groups, yet large variability within groups. Although patient characteristics are considered crucial in understanding outcome, they have received limited research attention. This trial aims at investigating the interaction between therapeutic approach (pre-structured versus explorative) and the personality style of patients (dependent versus self-critical), which is considered a core underlying dimension of depressive pathology. METHODS/DESIGN: This study is a pragmatic stratified (dependent and self-critical patients) parallel trial with equal randomization (allocation 1:1) conducted in Flanders, Belgium. One hundred and four patients will be recruited and randomized to either 16-20 sessions of cognitive behavioral therapy for depression (pre-structured approach) or 16-20 sessions of short-term psychodynamic psychotherapy for depression (explorative approach) conducted by trained psychotherapists in private practices. The primary outcome is the severity of depression as measured by the Hamilton Rating Scale for Depression at completion of therapy. Secondary outcome measures include self-reported depressive and other symptoms, interpersonal functioning, idiosyncratic complaints, and the presence of the diagnosis of depression. Additional measures include biological measures, narrative material (sessions, interviews), and health care costs. DISCUSSION: This trial presents the test of an often-described, yet hardly investigated interaction between important personality dimensions and therapeutic approach in the treatment of depression. Results could inform therapists on how to match psychotherapeutic treatments to specific personality characteristics of their patients. TRIAL REGISTRATION: Isrctn.com, ISRCTN17130982 . Registered on 2 February 2015.