A Personalized Approach to Effects of Affective Bias Modification on Symptom Change and Rumination
Condition: Major Depressive Disorder
MeSH terms: Rumination Syndrome; Depressive Disorder; Depressive Disorder, Major
Study type: Interventional

Summary: 
      This study evaluates the effect of a computerized intervention for depressive symptoms called
      Affective Bias Modification (ABM). A third of the patients will receive active ABM, a third
      will receive sham ABM and a third will undergo assessment only. The study will investigate if
      rumination mediates the effect of the intervention and investigate if specific symptom
      profiles affect the effect of the intervention.
    

Detailed description: 
      A main aim of the project is to investigate how the effects of an ABM intervention on
      depressive symptoms are mediated by transdiagnostic rumination and how characteristics of the
      symptom network moderate these effects. The Affective Bias Modification Task (ABM) will be
      applied in a randomized controlled, double blind clinical trial with 6 months follow-up.
      Personalized networks are generated from prospective assessment of depression-related
      processes at baseline and follow-ups. Patients (n = 150) will be recruited from out-patient
      clinics at Diakonhjemmet Hospital, and randomized into one of three conditions: active, sham
      and assessment only. Patients aged 18-65 with depression (major depressive disorder) or
      bipolar disorder 2, with or without comorbid anxiety and/or alcohol use disorder will be
      included. The main hypothesis is that subjects who are in the active ABM group will exhibit
      less tendency for stress related (state) rumination compared to those in the placebo group.
      Active vs placebo ABM will decrease depressive symptoms (6 months) and this effect will be
      mediated by the change in state rumination. Densely connected symptom network and high
      strength centrality of rumination at baseline will moderate the effect of ABM. By combining
      mechanisms research with a personalized symptom network approach, this study will be in the
      forefront of understanding how a drug-free treatment option works and for whom it works best.
    

Intervention name(s): Affective bias modification; Sham Affective bias modification
Intervention type(s): Behavioral; Behavioral
Intervention description(s): In the Affective bias modification (ABM) procedure, paired stimuli (e.g. a negative and a positive facial expression) are presented on a laptop screen, followed by one or two probes (dots) appearing in the spatial location of one of the stimuli. Participants are then required to press one of two buttons as quickly as possible to indicate the number of dots in the probe. Stimuli presentation time is 50% 500 ms and 50 % 1000 ms (evenly distributed throughout the task). In total, the ABM will comprise 90 trials of paired images of faces of different valences. In the active condition, the probe appears at the location of the most positive stimuli of each pair in 87 % of trials (encouraging a positive affective bias). Participants will do ABM in their homes (approx. 5 min.) twice a day for two weeks (28 sessions) using laptop computers provided by us.; In the Affective bias modification (ABM) procedure, paired stimuli (e.g. a negative and a positive facial expression) are presented on a laptop screen, followed by one or two probes (dots) appearing in the spatial location of one of the stimuli. Participants are then required to press one of two buttons as quickly as possible to indicate the number of dots in the probe. Stimuli presentation time is 50% 500 ms and 50 % 1000 ms (evenly distributed throughout the task). In total, the ABM will comprise 90 trials of paired images of faces of different valences. In the sham condition, the probe appears at the location of the most positive stimuli of each pair in 50 % of trials (no contingency between facial expressions shown and the probe location). Participants will do ABM in their homes (approx. 5 min.) twice a day for two weeks (28 sessions) using laptop computers provided by us.
Other intervention name(s): Attention Bias Modification; Sham Attention bias modification
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Rumination; Attention bias modification; Transdiagnostic