Mechanisms of Change in Psychotherapy

Study Overview
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Brief Summary
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Background: Major depressive disorder (MDD) is a prevalent psychiatric condition associated with significant disability, mortality and economic burden. MDD is ranked fourth in terms of disease burden as defined by the World Health Organization (2001). Cognitive Behavioral Therapy (CBT) and Psychodynamic Psychotherapy (PDT) are found to be equally effective for patients with depression. However, many patients do not respond sufficiently to treatment and relapse rates are high. To be able to offer individualized treatment, a clinically important question is therefore whether some patients profit more from one of the two therapies. At present little is known on which patient characteristics (moderators) may be associated with differential outcomes of CBT and PDT and through what kind of therapeutic processes and mechanisms (mediators) improvements occur in each therapy mode. There are actually only theoretical assumptions sparsely supported by research findings on what moderates and mediates the treatment effects of CBT and PDT. Aims: The overall aim of this project is to examine putative moderators and mediators in CBT and PDT and develop more basic knowledge about their impact on outcomes of psychotherapy for patients with MDD. Methods and study design: The study is a randomized clinical trial. One hundred patients will be randomized to one of two treatment conditions. The patients will be treated over 28 weeks with either CBT (one weekly session over 16 weeks and 3 booster sessions (monthly) during the rest of the 28 week study period) or PDT (one weekly session in 28 weeks). The patients will be evaluated at baseline, during therapy, at the end of therapy, and at follow-up investigations 1 and 3 years after treatment termination. The outcome measures comprise a large range of clinical and process variables, including assessment tools measuring specific preselected putative moderators and mediators. Discussion: The clinical outcome of this trial may guide clinicians to decide what kind of treatment should be offered the individual patient. Moreover, it will shed light on what kind of mechanisms in psychotherapy that is followed by symptom improvement and increased psychosocial functioning.

Official Title
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What Works for Whom and How? Mechanisms of Change in Psychotherapy

Conditions
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Depression

Intervention / Treatment
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* Other: Cognitive behavior therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients aged between 18-65 years, with depressive disorder according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV; American Psychiatric Association, 2000) unipolar MDD diagnosis will be included.MINI plus (Sheehan et al., 1998 will be used as assessment tool. Comorbidity is expected to be frequent. Written consent will be obtained from all patients. The participants need to have the ability to speak and understand a Scandinavian language, and willingness and ability to give informed consent. Exclusion Criteria: Current or past neurological illness, traumatic brain injury, current alcohol and/or substance dependency disorders, psychotic disorders, developmental disorders, and mental retardation.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: In this study we want to examine moderators and mediators in two equally effective, well known psychotherapeutic treatments (Psychodynamic and cognitive behavior therapy)
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cognitive behavior therapy<br>The included patients will receive cognitive therapy for depression for 16 weeks and monthly booster sessions up to 28 weeks. | Other: Cognitive behavior therapy<br>* In this study we want to compare CBT and PDT and examine whether some patients will benefit from CBT and other from PDT. More specifically we want to examine moderators and mediators for improvement in depressive symptoms in the two interventions arms.<br>* Other names: Psychodynamic psychotherapy;|
| Active Comparator: Psychodynamic psychotherapy<br>The included patients will receive time-limited psychodynamic psychotherapy for 28 weeks. | Other: Cognitive behavior therapy<br>* In this study we want to compare CBT and PDT and examine whether some patients will benefit from CBT and other from PDT. More specifically we want to examine moderators and mediators for improvement in depressive symptoms in the two interventions arms.<br>* Other names: Psychodynamic psychotherapy;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hamilton Depression Rating Scale | Assessment of depression | Change in scores between baseline and 28 weeks (end of therapy) and change between baseline and one and three year follow-up | 
| Beck Depression Index | Assessment of depression | Change in scores between baseline and 28 weeks (end of therapy) and change between baseline and one and three year follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Psychodynamic Functioning Scale | Assesment of dynamic functioning | Change in scores during therapy and the follow-up periode (one and three years) | 
| Beck Cognitive Insight Score | Assessment of cognitive insight | Change in scores during therapy and the follow-up periode (8 weeks, 16 weeks, 28 weeks, 1 year and 3 year follow up) | 
| Global Assesment of Functioning | Assessment of global symptoms and functioning | Change in scores during therapy and the follow-up periode (one and three years) | 
| Inventory of Interpersonal Problems | Measure of interpersonal problems | Change in scores during therapy and the follow-up periode (one and three years) | 
| Reflective functioning - depression | Assessment of reflective functioning | Change in scores during therapy and the follow-up periode (one and three years) | 
| Dysfunctional Attitude Scale | Measure of dysfunctional attitude | Change in scores during therapy and the follow-up periode (8 weeks, 16 weeks, 28 weeks, 1 year and 3 year follow up) | 
| Metacognitive questionnaire | Assessments of metacognition | Change in scores during therapy and the follow-up periode (8 weeks, 16 weeks, 28 weeks, 1 year and 3 year follow up) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cognitive behavior therapy, Psychodynamic therapy, Mediators, Moderators