Bayesian Sequential Single Case Methods to Personalize Low-Intensity Psychological Interventions: Initial Pilot Work

Study Overview
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Brief Summary
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The study is an initial investigation of the feasibility of applying Bayesian sequential analyses to individual participant single-case data for rapid detection of whether or not the individual is benefitting from a low-intensity computerized cognitive training intervention for depression. Patients waiting for, or in follow-up from, outpatient psychological therapy will complete first a two-week period of daily symptom monitoring, followed by two different two-week cognitive training interventions. Data collected will be used to assess feasibility of a future formal case series using Bayesian sequential analyses to determine switching of interventions, and inform the analysis parameters for such a future study.

Official Title
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Using Bayesian Sequential Single Case Methodology to Personalize Low-Intensity Psychological Interventions for Depression: Initial Pilot Work

Conditions
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Depression

Intervention / Treatment
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* Behavioral: Imagery Cognitive Bias Modification
* Behavioral: Cognitive Control Training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient registered at the Ruhr University of Bochum Outpatient Psychotherapy Center (Zentrum für Psychotherapie, ZPT) in an appropriate phase of treatment (on waiting list/ in follow-up), or from 26/10/22 having had a first consultation (Beratungsgespräch) Aged 18 years or above Owning a technical device (e.g. a laptop, computer) that is compatible with the computerized training Scoring ≥ 6 on the QIDS (indicating at least mild levels of depressive symptoms) Willing and able to complete all study procedures Exclusion Criteria: Existence of a condition or circumstances that would interfere with completion of the study procedures (e.g. severe visual impairment, neurological problem, acute psychosis, or substance withdrawal symptoms) Acute crisis with high levels of suicidal ideations or high levels of self-harm, identified either through therapist's assessment or score >1 on item 12 of the QIDS

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: Crossover Assignment
Interventional Model Description: The study is an exploratory single-case series using a within-subject ABC design, with a baseline phase (A) followed by two intervention phases (B) and (C). Participants are randomly assigned to the order in which they complete the two different interventions.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Imagery Cognitive Bias Modification First<br>After completing two weeks of daily QIDS (baseline phase), participants randomly allocated to this arm will complete two weeks of imagery cognitive bias modification followed by two weeks of cognitive control training. Daily QIDS will be completed throughout the intervention phases. | 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. The training aims to train a bias to automatically imagine positive resolutions for ambiguous situations encountered in daily life. Participants will complete one introductory session of the training with the researcher present (in the outpatient center, or via videoconferencing software), then 8 sessions over two weeks completed from home via the study website.<br>Behavioral: Cognitive Control Training<br>* The cognitive control training is an adaptive Paced Auditory Serial Addition Task (PASAT), adapted from that applied in previous studies (e.g. Siegle et al., 2007; Hoorelbeke et al., 2015; Blackwell et al., 2018). Participants will complete one introductory session of the training with the researcher present (in the outpatient center, or via videoconferencing software), then 8 sessions over two weeks completed from home via the study website.<br>|
| Experimental: Cognitive Control Training First<br>After completing two weeks of daily QIDS (baseline phase), participants randomly allocated to this arm will complete two weeks of cognitive control training followed by two weeks of imagery cognitive bias modification. Daily QIDS will be completed throughout the intervention phases. | 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. The training aims to train a bias to automatically imagine positive resolutions for ambiguous situations encountered in daily life. Participants will complete one introductory session of the training with the researcher present (in the outpatient center, or via videoconferencing software), then 8 sessions over two weeks completed from home via the study website.<br>Behavioral: Cognitive Control Training<br>* The cognitive control training is an adaptive Paced Auditory Serial Addition Task (PASAT), adapted from that applied in previous studies (e.g. Siegle et al., 2007; Hoorelbeke et al., 2015; Blackwell et al., 2018). Participants will complete one introductory session of the training with the researcher present (in the outpatient center, or via videoconferencing software), then 8 sessions over two weeks completed from home via the study website.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quick Inventory of Depressive Symptomatology - Self Report Daily Version (QIDS-daily) | The QIDS-daily is an adapted version of the QIDS-SR (Rush et al., 2003), which asks about symptoms over the past day and does not include the weight gain/loss items (as used by Holmes et al., 2016). The QIDS-daily will be completed daily over the entire study period, and we will compare the mean and slope of the daily QIDS over the intervention phase to the mean and slope of the daily QIDS in the previous phase. | End of intervention (4 weeks post-baseline) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quick Inventory of Depressive Symptomatology - Self Report (QIDS) | The standard QIDS-SR (Rush et al., 2003) is a measure of depression symptoms asking about symptoms over the past seven days. | Baseline, pre-intervention (2 weeks post-baseline), between interventions (4 weeks post-baseline), end of study (6 weeks post-baseline) | 
| Dimensional Anhedonia Rating Scale (DARS) | The DARS (Rizvi et al., 2015) is a 17-item self-report measure of different facets of anhedonia (desire, motivation, effort and consummatory pleasure) across different hedonic domains (hobbies/past-times, food/drinks, social activities, and sensory experiences). | Baseline, pre-intervention (2 weeks post-baseline), between interventions (4 weeks post-baseline), end of study (6 weeks post-baseline) | 
| Positive and Negative Affect Schedule - Positive subscale (PANAS-P) | This 18-item positive subscale comprises the Joviality, Self-Assurance, and Attentiveness subscales of the extended PANAS (PANAS-X; Watson & Clark, 1994), and in the current study asks about experience of positive emotions over the past week. | Baseline, pre-intervention (2 weeks post-baseline), between interventions (4 weeks post-baseline), end of study (6 weeks post-baseline) | 
| GAD-7 | The GAD-7 (Spitzer et al., 2006) is a brief (7 items) self-report anxiety questionnaire designed as a screener for Generalized Anxiety Disorder in primary care. | Baseline, pre-intervention (2 weeks post-baseline), between interventions (4 weeks post-baseline), end of study (6 weeks post-baseline) | 
| Positive Mental Health Scale (PMH) | The PMH (Lukat et al., 2016) consists of 9 items designed to assess positive mental health. | Baseline, pre-intervention (2 weeks post-baseline), between interventions (4 weeks post-baseline), end of study (6 weeks post-baseline) | 
| Prospective Imagery Test (PIT) | The PIT (Stöber, 2000) is a measure of the vividness with which participants can imagine positive events in their future. In the current study, two 10-item (5 positive and 5 negative) versions are used, with the order counterbalanced across participants. | Baseline, end of study (6 weeks post-baseline) | 
| Daily Expressions of Psychopathology (DEP) | From 26/10/22 onwards, the DEP is used in addition to the QIDS as a daily measure (completed after the QIDS each day). Nine questions in total were taken (from Wright & Zimmermann, 2021): three depression items, three anxiety items, and three anhedonia items. Participants are asked to rate each item according to much they applied in the past 24 hours, and using a scale from 0 (did not apply at all) to 6 (Applied very strongly). The DEP will be completed daily over the entire study period, and we will compare the mean and slope of the daily DEP over the intervention phase to the mean and slope of the daily DEP in the previous phase. | End of intervention (4 weeks post-baseline) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Depression, Anhedonia, Cognitive Bias Modification, Cognitive Control Training, Bayesian sequential analyses, Single case series