Feasibility Randomized Controlled Trial Using a 'Leapfrog' Design

Study Overview
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Brief Summary
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This study is a small-scale randomized controlled trial (RCT) using a 'Leapfrog' design (Blackwell, Woud, Margraf, & Schönbrodt, 2019) with the aim of investigating feasibility of this design in the context of an RCT of an internet-delivered intervention. The leapfrog design will be applied to a simple cognitive training intervention, imagery cognitive bias modification (imagery CBM), completed over a four-week training period. The trial will start with the three arms described in the initial registration, but these will be removed and new arms added over the course of the trial on the basis of sequential Bayesian analyses.

Official Title
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Feasibility Randomized Controlled Trial Using a 'Leapfrog' Design: Optimizing an Internet-delivered Cognitive Training Intervention to Reduce Anhedonia

Conditions
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Anhedonia, Depression

Intervention / Treatment
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* Behavioral: Imagery cognitive bias modification


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 18 or over Fluent German Willing and able to complete all study procedures (including having a suitable device/ internet access) Interested in monitoring their mood over the study time-period (one month) Score of ≥ 6 on the Quick Inventory of Depressive Symptomatology, including ≥ 1 on item 13 (General Interest), indicating at least mild levels of depression symptoms and anhedonia Exclusion Criteria: No exclusion criteria set

Ages Eligible for Study
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Minimum Age: 18 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: The leapfrog trial design is a parallel-arm design in which participants and randomly allocated to one of several treatment arms on a 1:1:1... ratio. One trial arm is designated the comparison arm, and all other arms are compared to this comparison arm via sequential Bayesian analyses. Depending on the outcomes of the sequential analyses (based on reaching Bayes Factor thresholds for 'success' or 'failure', trial arms may be removed, or take the place of the comparison arm while the trial is ongoing, and new arms may also be introduced into an ongoing trial.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Monitoring<br>Participants complete weekly questionnaires (QIDS-SR, PMH, GAD-7) on a weekly basis but receive no intervention. | |
| Experimental: Standard imagery cognitive bias modification<br>Participants are scheduled to complete a first introductory session then 12 further training sessions of a 'standard' imagery cognitive bias modification (CBM) intervention derived from that implemented in previous studies. | Behavioral: Imagery cognitive bias modification<br>* The imagery cognitive bias modification intervention is derived from that developed via experimental psychopathology research (e.g. Holmes et al., 2009) and adapted for clinical applications in the context of depression (e.g. Blackwell & Holmes, 2010; Blackwell et al., 2015). The intervention is a series of training sessions in which participants listen to training scenarios consisting of descriptions of everyday situations, structured so that they start ambiguously but always end positively. Participants are instructed to imagine themselves in the situations described as the scenarios unfold. It is hypothesised that via repeatedly practising imagining positive resolutions for ambiguous situations in the training sessions, a bias is trained to automatically imagine positive resolutions for ambiguous situations encountered in daily life.<br>|
| Experimental: Standard imagery cognitive bias modification plus additional rationale and transfer instructions<br>Participants are scheduled to complete a first introductory session then 12 further training sessions of a 'standard' imagery cognitive bias modification (CBM) intervention, but in addition are first presented with a more extended rationale for completing the training, and during each training session are provided with instructions to practice retrieval and rehearsal of the training contents in between sessions. | Behavioral: Imagery cognitive bias modification<br>* The imagery cognitive bias modification intervention is derived from that developed via experimental psychopathology research (e.g. Holmes et al., 2009) and adapted for clinical applications in the context of depression (e.g. Blackwell & Holmes, 2010; Blackwell et al., 2015). The intervention is a series of training sessions in which participants listen to training scenarios consisting of descriptions of everyday situations, structured so that they start ambiguously but always end positively. Participants are instructed to imagine themselves in the situations described as the scenarios unfold. It is hypothesised that via repeatedly practising imagining positive resolutions for ambiguous situations in the training sessions, a bias is trained to automatically imagine positive resolutions for ambiguous situations encountered in daily life.<br>|
| Experimental: Standard imagery cognitive bias modification with frequent brief sessions<br>Participants are scheduled to complete a first introductory session then 40 brief ( 5 min) sessions of a 'standard' imagery cognitive bias modification (CBM) intervention, with 2 per day five days per week for each of the four training weeks. In addition, as with the arm Standard imagery cognitive bias modification plus additional rationale and transfer instructions, participants are first presented with a more extended rationale for completing the training, and during many of the training sessions are provided with instructions to practice retrieval and rehearsal of the training contents in between sessions. This arm was added into the ongoing trial on 30.05.21. | Behavioral: Imagery cognitive bias modification<br>* The imagery cognitive bias modification intervention is derived from that developed via experimental psychopathology research (e.g. Holmes et al., 2009) and adapted for clinical applications in the context of depression (e.g. Blackwell & Holmes, 2010; Blackwell et al., 2015). The intervention is a series of training sessions in which participants listen to training scenarios consisting of descriptions of everyday situations, structured so that they start ambiguously but always end positively. Participants are instructed to imagine themselves in the situations described as the scenarios unfold. It is hypothesised that via repeatedly practising imagining positive resolutions for ambiguous situations in the training sessions, a bias is trained to automatically imagine positive resolutions for ambiguous situations encountered in daily life.<br>|
| Experimental: Standard imagery cognitive bias modification with a less intensive schedule<br>Participants are scheduled to complete a first introductory session then 11 further sessions of a 'standard' imagery cognitive bias modification (CBM) intervention, with 3 sessions scheduled for each of the four training weeks. Sessions have fewer training scenarios than the Standard imagery cognitive bias modification condition and more varied task instructions. In addition, as with the arm Standard imagery cognitive bias modification plus additional rationale and transfer instructions, participants are first presented with a more extended rationale for completing the training, and during many of the training sessions are provided with instructions to practice retrieval and rehearsal of the training contents in between sessions. This arm was added into the ongoing trial on 09.06.21. | Behavioral: Imagery cognitive bias modification<br>* The imagery cognitive bias modification intervention is derived from that developed via experimental psychopathology research (e.g. Holmes et al., 2009) and adapted for clinical applications in the context of depression (e.g. Blackwell & Holmes, 2010; Blackwell et al., 2015). The intervention is a series of training sessions in which participants listen to training scenarios consisting of descriptions of everyday situations, structured so that they start ambiguously but always end positively. Participants are instructed to imagine themselves in the situations described as the scenarios unfold. It is hypothesised that via repeatedly practising imagining positive resolutions for ambiguous situations in the training sessions, a bias is trained to automatically imagine positive resolutions for ambiguous situations encountered in daily life.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dimensional Anhedonia Rating Scale (DARS) | A 17-item scale measuring anhedonia (Rizvi et al., 2015). The primary analysis is a between-groups comparison of post-intervention scores, controlling for baseline scores, using constrained longitudinal data analysis (cLDA). An approximate Bayes factor is then calculated via the t-statistic for the Time x Group effect with a directional default Cauchy prior (rscale parameter = √2/2). | Post-intervention (4 weeks post-baseline). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quick Inventory of Depressive Symptomatology - Self Report (QIDS) | A 15-item version of the QIDS (Rush et al., 2013), excluding the suicidal ideation item, will be used | Baseline, 1 week post-baseline, 2 weeks post-baseline, 3 weeks post-baseline, post-intervention (4 weeks post-baseline) | 
| GAD-7 | A brief 7-item measure of generalized anxiety symptoms (Spitzer et al., 2006) | Baseline, 1 week post-baseline, 2 weeks post-baseline, 3 weeks post-baseline, post-intervention (4 weeks post-baseline) | 
| Positive Mental Health Scale (PMH) | A 9-item questionnaire designed to assess positive mental health (Lukat et al., 2016) | Baseline, 1 week post-baseline, 2 weeks post-baseline, 3 weeks post-baseline, post-intervention (4 weeks post-baseline) | 
| Ambiguous Scenarios Test for Depression (AST) | A measure with two 15-item parallel forms designed to assess depression-relevant negative interpretation biases (Rochbacher & Reinecke, 2014) | Baseline and post-intervention (4 weeks post-baseline) | 
| Prospective Imagery Test (PIT) | A measure designed to assess vividness of positive and negative future-oriented imagery (Stöber et al., 2000), here administered with as two 10-item parallel versions (each with 5 positive and 5 negative items). | Baseline and post-intervention (4 weeks post-baseline) | 
| Negative Effects Questionnaire - Short Form (NEQ) | A 20-item questionnaire designed to assess potential negative effects of psychological interventions (Rozental et al., 2019) | Post-intervention (4 weeks post-baseline) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Leapfrog Design, Cognitive Bias Modification, Mental Imagery