The Modulatory Role of Communicated Treatment Rationale on Treatment Expectation Effects in Depression.

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.

Study Overview

• Status: Completed
• Conditions: Condition: Major Depressive Disorder (MDD)
• Intervention / Treatment: Behavioral: Biological illness and treatment rationale; Drug: Active pharmacological placebo; Behavioral: Psychological illness and treatment rationale; Behavioral: Active psychological placebo

• Study Type: Interventional
• Enrollment (Actual): 150
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • Marburg, Germany, 35032
    • Department of Clinical Psychology and Psychotherapy, Philipps-University Marburg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 1. Congruent Rationale & Treatment: Biological/Pharmacol.; Participants receive a biological illness explanation and treatment rationale. During treatment they receive a placebo pill (Buscopan).	Behavioral: Biological illness and treatment rationale; Depression is described as a brain disorder and the role of monoamine, brain structures, and brain functions are reported as central mechanisms of relevance for its etiology and treatment. Biological processes are illustrated using typical charts and visualizations. Psychological influences are mentioned, but only as a byproduct of the disorder.; Drug: Active pharmacological placebo; The active placebo pill does not have direct effects on the brain. Buscopan (butylscopolamine, 10 mg daily, 1 pill in the morning) does not cross the blood-brain barrier, yet induces some smaller side effects that resemble those of antidepressants (e.g., mouth dryness, fatigue, nausea). Treatment duration is 4 weeks. The rationale is briefly explained to participants as "stimulating the biological balance in humans with depression, using a well-tolerated drug similar to Buscopan, which is well-known from pain treatments.
Experimental: 2. Incongruent Rationale & Treatment: Psychological/Pharmacol.; Participants receive a psychological illness explanation and treatment rationale. During treatment they receive a placebo pill (Buscopan).	Drug: Active pharmacological placebo; The active placebo pill does not have direct effects on the brain. Buscopan (butylscopolamine, 10 mg daily, 1 pill in the morning) does not cross the blood-brain barrier, yet induces some smaller side effects that resemble those of antidepressants (e.g., mouth dryness, fatigue, nausea). Treatment duration is 4 weeks. The rationale is briefly explained to participants as "stimulating the biological balance in humans with depression, using a well-tolerated drug similar to Buscopan, which is well-known from pain treatments.; Behavioral: Psychological illness and treatment rationale; Depression is described as a psychological disorder resulting from emotion regulation deficits. The suppression of emotions receives a special role in explaining depression. The psychological processes are illustrated using charts and visualizations. Biological aspects are mentioned, but only as a byproduct of the disorder.
Experimental: 3. Congruent Rationale & Treatment: Psychological/Psychol.; Participants receive a psychological illness explanation and treatment rationale. During treatment they receive a placebo psychological treatment (emotional writing).	Behavioral: Psychological illness and treatment rationale; Depression is described as a psychological disorder resulting from emotion regulation deficits. The suppression of emotions receives a special role in explaining depression. The psychological processes are illustrated using charts and visualizations. Biological aspects are mentioned, but only as a byproduct of the disorder.; Behavioral: Active psychological placebo; "Emotional writing" consists of writing about emotional experiences (4 sessions, one per week, 30 minutes each). The study instructor will be present displaying standard psychotherapeutic attitudes but will not read the participant's notes. The rationale for this treatment is briefly explained as "improving the dealing" with emotions to achieve a psychological balance in humans with depression.
Experimental: 4. Incongruent Rationale & Treatment: Biological/Psychol.; Participants receive a biological illness explanation and treatment rationale. During treatment they receive a placebo psychological treatment (emotional writing).	Behavioral: Biological illness and treatment rationale; Depression is described as a brain disorder and the role of monoamine, brain structures, and brain functions are reported as central mechanisms of relevance for its etiology and treatment. Biological processes are illustrated using typical charts and visualizations. Psychological influences are mentioned, but only as a byproduct of the disorder.; Behavioral: Active psychological placebo; "Emotional writing" consists of writing about emotional experiences (4 sessions, one per week, 30 minutes each). The study instructor will be present displaying standard psychotherapeutic attitudes but will not read the participant's notes. The rationale for this treatment is briefly explained as "improving the dealing" with emotions to achieve a psychological balance in humans with depression.
No Intervention: 5. Natural course control; Participants receive no intervention and remain on the psychotherapy waiting list. Participants who are recruited externally and are not on a waiting list, will be offered the option to join the waiting list.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in depression severity scores after 4 weeks of treatment - 'Montgomery Asberg Depression Scale' (MADRS)	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)	Baseline, post-treatment (4 weeks after start of treatment)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in depressive symptom scores after 4 weeks of treatment- 'Beck Depression Inventory' (BDI-II)	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)	Baseline, post-treatment (4 weeks after start of treatment), and at follow-up (1 week later)
Change in subjective disability scores after 4 weeks of treatment - adaptation of 'Pain Disability Index' (PDI)	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)	Pre-treatment (2-7 days after baseline), post-treatment (4 weeks after start of treatment), and at follow-up (1 week later)
Change in 'Generic Assessment of Side-Effects' scores (GASE) after 4 weeks of treatment	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)	Pre-treatment (2-7 days after baseline), post-treatment (4 weeks after start of treatment), and at follow-up (1 week later)
Change in treatment expectations at the start of treatment - 'Treatment Expectation Questionnaire' (TEX-Q)	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)	Baseline, pre-treatment (2-7 days after baseline)
Change in subjective stress scores after 4 weeks of treatment - 'Perceived Stress Scale' (PSS-10)	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)	pre-treatment (2-7 days after baseline), post-treatment (4 weeks after start of treatment), and at follow-up (1 week later)
Change in anxiety scores after 4 weeks of treatment - 'State-Trait-Anxiety- Depression-Inventory' (STADI)	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)	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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
Treatment adherence	Count of remaining pills per week; participation in weekly therapy sessions	Once per week (during the 4-week treatment period)
Common biological stress markers	Salivary Alpha-Amylase and cortisol levels	Baseline
Current treatment effects after 4 weeks of treatment	Generic questions to assess perceived treatment effects; 3 items, each rated on a 0(no improvement) - 10(most improvement imaginable) numeric scale; total scores range from 0-30 (higher scores indicate better treatment expectations)	post-treatment (4 weeks after start of treatment)
Current treatment effects at follow-up	Generic questions to assess perceived treatment effects; 3 items, each rated on a 0(no improvement) - 10(most improvement imaginable) numeric analogue scale; total scores range from 0-30 (higher scores indicate better treatment expectations)	at follow-up (1 week after end of treatment)
Change in generic expectations about antidepressants at the start of treatment	Generic questions assess pre-existing expectations about antidepressants; 3 items; items are rated on a 0(no expectation of improvement) - 10(most improvement imaginable) numeric analogue scale; total scores range from 0-30 (higher scores indicate better antidepressant treatment expectations)	Baseline; pre-treatment (2-7 days after baseline)
Change in generic expectations about psychotherapy at the start of treatment	Generic questions to assess pre-existing expectations about psychotherapy; 3 items; items are rated on a 0(no expectation of improvement) - 10(most improvement imaginable) numeric analogue scale; total scores range from 0-30 (higher scores indicate better psychotherapy treatment expectations)	Baseline, pre-treatment (2-7 days after baseline)
'Somatosensory Amplification Scale' (SSAS)	Self-report questionnaire to assess amount of somatosensory amplification tendencies; 10 items; items are rated on a 5-point scale from 1(not at all true) - 5(extremely true); total scores range from 10-50 (higher scores indicate more somatosensory amplification)	Baseline
'Behavioral Inhibition/Behavioral Approach System' Scale (BIS/BAS)	Self-report questionnaire to assess sensitivity to approach or avoidance goals; 24 items; each item is rated on a 4-point scale from 1(not at all true for me) to 4(very true for me)	Baseline
Generic screening pre-experiences with antidepressants	Generic questions to assess pre-existing experiences with antidepressants; 4 items; if experience with antidepressants is indicated in item 1, the following 3 items are rated on a 0(no improvement) - 10(most improvement imaginable) numeric analogue scale; total scores range from 0-30 (higher scores indicate better past experiences with antidepressants)	Baseline
Generic screening pre-experiences with psychotherapy	Generic questions to assess pre-existing experiences with psychotherapy; 4 items; if experience with psychotherapy is indicated in item 1, the following 3 items are rated on a 0 (no improvement)-10(most improvement imaginable) numeric analogue scale; total scores range from 0-30 (higher scores indicate better past experiences with psychotherapy)	Baseline

Collaborators and Investigators

• Sponsor: Philipps University Marburg Medical Center
• Collaborators: Psychotherapie-Ambulanz Marburg e.V.
• Investigators: Principal Investigator: Winfried Rief, Philipps University Marburg Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): April 13, 2021
• Primary Completion (Actual): September 12, 2023
• Study Completion (Actual): September 12, 2023

Study Registration Dates

• First Submitted: January 6, 2021
• First Submitted That Met QC Criteria: January 19, 2021
• First Posted (Actual): January 22, 2021

Study Record Updates

• Last Update Posted (Estimated): November 16, 2023
• Last Update Submitted That Met QC Criteria: November 15, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Keywords: Depression; Expectations; Placebo effect; Treatment rationale
• Additional Relevant MeSH Terms: Behavioral Symptoms; Mental Disorders; Mood Disorders; Depression; Depressive Disorder; Depressive Disorder, Major
• Other Study ID Numbers: CRC 289 Project A16

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No