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NCT Number: NCT04719663

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.

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Key information

Conditions

Condition: Major Depressive Disorder (MDD) Behavior Behavioral Symptoms Depression

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Clinical Psychology and Psychotherapy, Philipps-University Marburg

Marburg, 35032, Germany

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Biological illness and treatment rationale

Behavioral

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.

Psychological illness and treatment rationale

Behavioral

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.

Active pharmacological placebo

Drug

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.

Active psychological placebo

Behavioral

"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.

Primary outcomes

  1. Change in depression severity scores after 4 weeks of treatment - 'Montgomery Asberg Depression Scale' (MADRS)

    Time frame: 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 outcomes

  1. Change in depressive symptom scores after 4 weeks of treatment- 'Beck Depression Inventory' (BDI-II)

    Time frame: 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)

  2. Change in subjective disability scores after 4 weeks of treatment - adaptation of 'Pain Disability Index' (PDI)

    Time frame: 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)

  3. Change in 'Generic Assessment of Side-Effects' scores (GASE) after 4 weeks of treatment

    Time frame: 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)

  4. Change in treatment expectations at the start of treatment - 'Treatment Expectation Questionnaire' (TEX-Q)

    Time frame: 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)

  5. Change in subjective stress scores after 4 weeks of treatment - 'Perceived Stress Scale' (PSS-10)

    Time frame: 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)

  6. Change in anxiety scores after 4 weeks of treatment - 'State-Trait-Anxiety- Depression-Inventory' (STADI)

    Time frame: 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)

Other outcomes

  1. Treatment adherence

    Time frame: Once per week (during the 4-week treatment period)

    Count of remaining pills per week; participation in weekly therapy sessions

  2. Common biological stress markers

    Time frame: Baseline

    Salivary Alpha-Amylase and cortisol levels

  3. Current treatment effects after 4 weeks of treatment

    Time frame: post-treatment (4 weeks after start 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)

  4. Current treatment effects at follow-up

    Time frame: at follow-up (1 week after end of treatment)

    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)

  5. Change in generic expectations about antidepressants at the start of treatment

    Time frame: Baseline; pre-treatment (2-7 days after baseline)

    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)

  6. Change in generic expectations about psychotherapy at the start of treatment

    Time frame: Baseline, pre-treatment (2-7 days after baseline)

    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)

  7. 'Somatosensory Amplification Scale' (SSAS)

    Time frame: Baseline

    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)

  8. 'Behavioral Inhibition/Behavioral Approach System' Scale (BIS/BAS)

    Time frame: Baseline

    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)

  9. Generic screening pre-experiences with antidepressants

    Time frame: Baseline

    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)

  10. Generic screening pre-experiences with psychotherapy

    Time frame: Baseline

    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)

Sponsors and collaborators

Lead sponsor

Philipps University Marburg

Other

Collaborators

  • Psychotherapie-Ambulanz Marburg e.V.

Registry information

Important dates

Study start
2021
Primary completion
2023
Study completion
2023
First posted
Jan 22, 2021
Registry last updated
Nov 18, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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