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| Name | Class |
|---|---|
| Ludwig-Maximilians - University of Munich | OTHER |
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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.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Monitoring | No Intervention | Participants complete weekly questionnaires (QIDS-SR, PMH, GAD-7) on a weekly basis but receive no intervention. | |
| Standard imagery cognitive bias modification | Experimental | 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. |
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| Standard imagery cognitive bias modification plus additional rationale and transfer instructions | Experimental | 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. |
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| Standard imagery cognitive bias modification with frequent brief sessions | Experimental | 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. |
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Imagery cognitive bias modification | Behavioral | 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. |
| 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). |
| 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 |
| Measure | Description | Time Frame |
|---|---|---|
| Spontaneous Use of Imagery Scale (SUIS) | A 12-item questionnaire assessing experience of spontaneous non-emotional mental imagery in daily life (Reisberg et al., 2003) | Baseline |
| Credibility / Expectancy Questionnaire (CEQ) |
Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Simon E Blackwell, Dr. phil. | Ruhr University of Bochum | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Ruhr University of Bochum | Bochum | North Rhine-Westphalia | 44801 | Germany |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| Background | Blackwell, S. E., Woud, M. L., Margraf, J., & Schönbrodt, F. D. (2019). Introducing the leapfrog design: A simple Bayesian adaptive rolling trial design for accelerated treatment development and optimization. Clinical Psychological Science, 7, 1222-1243. https://doi.org/10.1177/2167702619858071 | ||
| 36330836 | Derived | Blackwell SE, Schonbrodt FD, Woud ML, Wannemuller A, Bektas B, Braun Rodrigues M, Hirdes J, Stumpp M, Margraf J. Demonstration of a 'leapfrog' randomized controlled trial as a method to accelerate the development and optimization of psychological interventions. Psychol Med. 2023 Oct;53(13):6113-6123. doi: 10.1017/S0033291722003294. Epub 2022 Nov 4. |
| Label | URL |
|---|---|
| Link for participants to enrol | View source |
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Anonymised data will be made available on publication via a suitable repository such as the Open Science Framework, and will be made available to reviewers at the time of submission (or publically with a pre-print version of the manuscript). Data made available will be the research data reported in the publication, with the exception of any data that could compromise participant anonymity.
Supporting information will be made available on publication via a suitable repository such as the Open Science Framework, and will be made available to reviewers at the time of submission (or publically with a pre-print version of the manuscript).
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| ID | Term |
|---|---|
| D059445 | Anhedonia |
| D003863 | Depression |
| ID | Term |
|---|---|
| D019954 | Neurobehavioral Manifestations |
| D009461 | Neurologic Manifestations |
| D009422 | Nervous System Diseases |
| D012816 | Signs and Symptoms |
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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.
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Participants are not blind as to whether they are receiving an intervention or monitoring only, but otherwise are blind to the status of which intervention they are receiving, i.e. 'original' version of the imagery CBM or an attempted improvement. Researchers are not blind to participant allocations, but the study is planned to be mostly automated, reducing opportunities to influence participants. Researchers will monitor performance of the arms as data accumulates, via the sequential analyses, and will therefore not be blind to outcomes as the trial progresses.
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| Standard imagery cognitive bias modification with a less intensive schedule | Experimental | 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. |
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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) |
A 6-item questionnaire assessing participants' evaluation of the credibility of an intervention (3 items) and their expectancy of symptom improvement (3 items) over the course of an intervention (Devilly & Borkovec, 2000)
| Baseline |
| Feedback questionnaire | A questionnaire containing both rating scales and open questions for eliciting participants' feedback about the study and interventions completed (if applicable) | Post-intervention (4 weeks post-baseline) |
| D013568 | Pathological Conditions, Signs and Symptoms |
| D001526 | Behavioral Symptoms |
| D001519 | Behavior |