Clinical trial NCT04719663: The Modulatory Role of Communicated Treatment Rationale on Treatment Expectation Effects in Depression.
Official title: The Modulatory Role of Communicated Treatment Rationale on Treatment Expectation Effects in Depression.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Condition: Major Depressive Disorder (MDD)
Keywords: Placebo effect
Treatment rationale
Depression
Expectations
Lead sponsor: Philipps University Marburg
Sponsor class: OTHER
Collaborators: name: Psychotherapie-Ambulanz Marburg e.V.
First posted: 2021-01-22
Enrollment: 150
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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.


Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Primary outcomes:
measure: Change in depression severity scores after 4 weeks of treatment - 'Montgomery Asberg Depression Scale' (MADRS)
timeFrame: Baseline, post-treatment (4 weeks after start of treatment)
Secondary outcomes:
measure: Change in depressive symptom scores after 4 weeks of treatment- 'Beck Depression Inventory' (BDI-II)
timeFrame: Baseline, post-treatment (4 weeks after start of treatment), and at follow-up (1 week later)
measure: Change in subjective disability scores after 4 weeks of treatment - adaptation of 'Pain Disability Index' (PDI)
timeFrame: Pre-treatment (2-7 days after baseline), post-treatment (4 weeks after start of treatment), and at follow-up (1 week later)
measure: Change in 'Generic Assessment of Side-Effects' scores (GASE) after 4 weeks of treatment
timeFrame: Pre-treatment (2-7 days after baseline), post-treatment (4 weeks after start of treatment), and at follow-up (1 week later)
measure: Change in treatment expectations at the start of treatment - 'Treatment Expectation Questionnaire' (TEX-Q)
timeFrame: Baseline, pre-treatment (2-7 days after baseline)
measure: Change in subjective stress scores after 4 weeks of treatment - 'Perceived Stress Scale' (PSS-10)
timeFrame: pre-treatment (2-7 days after baseline), post-treatment (4 weeks after start of treatment), and at follow-up (1 week later)
measure: Change in anxiety scores after 4 weeks of treatment - 'State-Trait-Anxiety- Depression-Inventory' (STADI)
timeFrame: 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
Other outcomes:
measure: Treatment adherence
timeFrame: Once per week (during the 4-week treatment period)
measure: Common biological stress markers
timeFrame: Baseline
measure: Current treatment effects after 4 weeks of treatment
timeFrame: post-treatment (4 weeks after start of treatment)
measure: Current treatment effects at follow-up
timeFrame: at follow-up (1 week after end of treatment)
measure: Change in generic expectations about antidepressants at the start of treatment
timeFrame: Baseline; pre-treatment (2-7 days after baseline)
measure: Change in generic expectations about psychotherapy at the start of treatment
timeFrame: Baseline, pre-treatment (2-7 days after baseline)
measure: 'Somatosensory Amplification Scale' (SSAS)
timeFrame: Baseline
measure: 'Behavioral Inhibition/Behavioral Approach System' Scale (BIS/BAS)
timeFrame: Baseline
measure: Generic screening pre-experiences with antidepressants
timeFrame: Baseline
measure: Generic screening pre-experiences with psychotherapy
timeFrame: Baseline
Locations:
city: Marburg
country: Germany
facility: Department of Clinical Psychology and Psychotherapy, Philipps-University Marburg
Study officials:
affiliation: Philipps University Marburg
name: Winfried Rief
role: PRINCIPAL_INVESTIGATOR
References: