The Modulatory Role of Communicated Treatment Rationale on Treatment Expectation Effects in Depression.
- Conditions
- Condition: Major Depressive Disorder (MDD)
- Interventions
- Behavioral: Psychological illness and treatment rationaleBehavioral: Biological illness and treatment rationaleDrug: Active pharmacological placeboBehavioral: Active psychological placebo
- Registration Number
- NCT04719663
- Lead Sponsor
- Philipps University Marburg Medical Center
- Brief Summary
Placebo groups in clinical trials on depression show impressive improvements. Yet, there is little research on the mechanism underlying this effect. The aim of this study is to assess how patients' treatment expectations modulate the placebo treatment effects.
We expect that patients' treatment expectation determines placebo responses and treatment outcomes, and that this expectation is influenced by the disorder explanations (information about the illness models) typically provided during the initial medical encounters that precede treatment.
In the study we aim to manipulate depressed patients' expectations by providing two different clinician-delivered illness and treatment rationales (biological/ psychological). Patients will then receive placebo treatment (pharmacological/ psychological), that is either congruent or incongruent with the previously communicated treatment rationale.
Hypotheses:
1. Providing a treatment-congruent treatment rationale leads to a better outcome than providing treatment-incongruent rationales.
2. Treatment-congruent explanations reduce the risk of side effect development, in particular in the medication arm.
3. Inter-individual differences in the effect of provided treatment rationale are associated with pre-treatment experiences and expectations, depression severity and comorbid anxiety.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 150
- Diagnosis of major depression according to the 'Structured Clinical Interview for DSM-V' (SCID)
- Age>17
- Comorbidity is allowed if major depression is the dominant clinical problem
- Concordant medication is allowed if kept constant for the four weeks before and until the end of the trial (with the exception of benzodiazepines and if not contraindicated together with Buscopan)
- Fluency in German
- Informed consent
- Severe depression (BDI> 30) or suicidality
- Psychosis
- Significant neurological diseases
- Other mental or physical disorder with substantial influence on disability
- Benzodiazepine intake
- Any intolerance against Buscopan and sucrose or any medical condition/treatment conflicting with Buscopan intake
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description 1. Congruent Rationale & Treatment: Biological/Pharmacol. Active pharmacological placebo Participants receive a biological illness explanation and treatment rationale. During treatment they receive a placebo pill (Buscopan). 2. Incongruent Rationale & Treatment: Psychological/Pharmacol. Psychological illness and treatment rationale Participants receive a psychological illness explanation and treatment rationale. During treatment they receive a placebo pill (Buscopan). 2. Incongruent Rationale & Treatment: Psychological/Pharmacol. Active pharmacological placebo Participants receive a psychological illness explanation and treatment rationale. During treatment they receive a placebo pill (Buscopan). 3. Congruent Rationale & Treatment: Psychological/Psychol. Psychological illness and treatment rationale Participants receive a psychological illness explanation and treatment rationale. During treatment they receive a placebo psychological treatment (emotional writing). 1. Congruent Rationale & Treatment: Biological/Pharmacol. Biological illness and treatment rationale Participants receive a biological illness explanation and treatment rationale. During treatment they receive a placebo pill (Buscopan). 3. Congruent Rationale & Treatment: Psychological/Psychol. Active psychological placebo Participants receive a psychological illness explanation and treatment rationale. During treatment they receive a placebo psychological treatment (emotional writing). 4. Incongruent Rationale & Treatment: Biological/Psychol. Biological illness and treatment rationale Participants receive a biological illness explanation and treatment rationale. During treatment they receive a placebo psychological treatment (emotional writing). 4. Incongruent Rationale & Treatment: Biological/Psychol. Active psychological placebo Participants receive a biological illness explanation and treatment rationale. During treatment they receive a placebo psychological treatment (emotional writing).
- Primary Outcome Measures
Name Time Method Change in depression severity scores after 4 weeks of treatment - 'Montgomery Asberg Depression Scale' (MADRS) Baseline, post-treatment (4 weeks after start of treatment) Expert rating to assess depression severity; 10 items; each item is rated on a 7-point scale (0-6); total scores range between 0-60 (higher scores indicate more severe depression)
- Secondary Outcome Measures
Name Time Method Change in subjective disability scores after 4 weeks of treatment - adaptation of 'Pain Disability Index' (PDI) Pre-treatment (2-7 days after baseline), post-treatment (4 weeks after start of treatment), and at follow-up (1 week later) Self-report questionnaire to assess illness burden; 7 items; each item rated on a 0 (no disability)-10(maximum disability) standardized numerical analogue scale; total scores range from 0-70 (higher scores indicate more disability)
Change in treatment expectations at the start of treatment - 'Treatment Expectation Questionnaire' (TEX-Q) Baseline, pre-treatment (2-7 days after baseline) Self-report questionnaire to assess expectations about treatment outcomes; 15 items; each rated on a 0 (no expectation of improvement)- 10(most improvement imaginable) numeric scale; total scores range from 0-150 (higher scores indicate better treatment expectations)
Change in subjective stress scores after 4 weeks of treatment - 'Perceived Stress Scale' (PSS-10) pre-treatment (2-7 days after baseline), post-treatment (4 weeks after start of treatment), and at follow-up (1 week later) Self-report questionnaire to assess subjective stress experience; 10 items; each item is rated on a 5-point scale from 0(never) to 4(very often); total scores range between 0 and 40 (higher scores indicate more subjective stress)
Change in anxiety scores after 4 weeks of treatment - 'State-Trait-Anxiety- Depression-Inventory' (STADI) State scale: Baseline; pre-treatment (2-7 days after baseline), post-treatment (4 weeks after start of treatment) and at follow-up (1 week later); Trait scale only measured at baseline Self-report questionnaire to assess state and trait anxiety and depression; 40 (20 state scale; 20 trait scale) items; each item is rated on a 4-point scale from 1(not at all) to 4(very much); total scores per scale range between 20 and 80 (higher scores indicate more anxiety)
Change in depressive symptom scores after 4 weeks of treatment- 'Beck Depression Inventory' (BDI-II) Baseline, post-treatment (4 weeks after start of treatment), and at follow-up (1 week later) Self-report questionnaire to assess subjective depression symptomatology; 21 items (each item response is scored 0-3); total scores range from 0 - 63 (higher scores indicate more depressiveness)
Change in 'Generic Assessment of Side-Effects' scores (GASE) after 4 weeks of treatment Pre-treatment (2-7 days after baseline), post-treatment (4 weeks after start of treatment), and at follow-up (1 week later) Self-report questionnaire to assess experience of side effects; 36 items; each item describes a side-effect symptom which is rated on a 4-point scale from 0 (not present)-3 (strong experience); total scores range from 0-108 (higher scores indicate stronger experience of side effects)
Trial Locations
- Locations (1)
Department of Clinical Psychology and Psychotherapy, Philipps-University Marburg
🇩🇪Marburg, Germany