Anhedonia, Depression
Conditions
Keywords
Cognitive Bias Modification, Mental Imagery, Leapfrog Design
Brief summary
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.
Interventions
BEHAVIORALImagery cognitive bias modification
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.
Sponsors
Ludwig-Maximilians - University of Munich
Ruhr University of Bochum
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Masking description
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.
Intervention 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.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Dimensional Anhedonia Rating Scale (DARS) | Post-intervention (4 weeks post-baseline). | 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). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Positive Mental Health Scale (PMH) | Baseline, 1 week post-baseline, 2 weeks post-baseline, 3 weeks post-baseline, post-intervention (4 weeks post-baseline) | A 9-item questionnaire designed to assess positive mental health (Lukat et al., 2016) |
| Ambiguous Scenarios Test for Depression (AST) | Baseline and post-intervention (4 weeks post-baseline) | A measure with two 15-item parallel forms designed to assess depression-relevant negative interpretation biases (Rochbacher & Reinecke, 2014) |
| Prospective Imagery Test (PIT) | Baseline and post-intervention (4 weeks post-baseline) | 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). |
| Negative Effects Questionnaire - Short Form (NEQ) | Post-intervention (4 weeks post-baseline) | A 20-item questionnaire designed to assess potential negative effects of psychological interventions (Rozental et al., 2019) |
| Quick Inventory of Depressive Symptomatology - Self Report (QIDS) | Baseline, 1 week post-baseline, 2 weeks post-baseline, 3 weeks post-baseline, post-intervention (4 weeks post-baseline) | A 15-item version of the QIDS (Rush et al., 2013), excluding the suicidal ideation item, will be used |
| GAD-7 | Baseline, 1 week post-baseline, 2 weeks post-baseline, 3 weeks post-baseline, post-intervention (4 weeks post-baseline) | A brief 7-item measure of generalized anxiety symptoms (Spitzer et al., 2006) |
Other
| Measure | Time frame | Description |
|---|---|---|
| Feedback questionnaire | Post-intervention (4 weeks post-baseline) | A questionnaire containing both rating scales and open questions for eliciting participants' feedback about the study and interventions completed (if applicable) |
| Spontaneous Use of Imagery Scale (SUIS) | Baseline | A 12-item questionnaire assessing experience of spontaneous non-emotional mental imagery in daily life (Reisberg et al., 2003) |
| Credibility / Expectancy Questionnaire (CEQ) | 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) |
Countries
Germany
Outcome results
None listed