Dynamic Learning in Depression
Condition: Depression
MeSH terms: Depression; Depressive Disorder
Study type: Interventional

Summary: 
      This study will assess learning bias (the tendency to learn more from negative relative to
      positive outcomes) at baseline in 3 groups of participants (currently depressed, previously
      depressed and never depressed). It will then try to modify this bias using a simple
      computerised training task completed at home daily for 2 weeks. Outcome measures include
      symptoms of depression, cognitive measures (i.e. accuracy and reaction time during completion
      of tasks), pupillometry measures and salivary cortisol.
    

Detailed description: 
      Depressed patients tend to focus on negative, at the expense of positive, events. This bias
      of attention is thought to be one factor which causes some people to be at higher risk of
      developing depression. One reason depressed people might pay more attention to negative
      events is that they think those events are more useful to them when they learn about the
      future. In this study the investigators will compare the learning styles (i.e. whether
      participants focus more on negative or positive information when learning about the future),
      cognitive biases and salivary cortisol levels (the levels of the hormone cortisol can be
      measured in the saliva and is known to be raised in those at risk of depression) of currently
      depressed (N=40), previously depressed (N=40) and never depressed (N=40) participants. The
      study will then randomly assign participants to complete one of two version of a learning
      task daily over two weeks. One version of the task will be designed to encourage an
      optimistic learning style, whereas the other will encourage neither an optimistic nor
      pessimistic learning style. The study will then retest participants' learning styles,
      cognitive biases, salivary cortisol and mood (using questionnaire measures) after completion
      of the task and again after 1 month. Study activities for participants will be: Screening
      visit (1 hours), baseline test visit (2 hours), task completion at home (10 mins per day for
      2 weeks), test visit 2 (2 hours, completed 2 weeks after baseline visit) and test visit 3 (2
      hours, completed 1 month after test visit 2). Participants will be asked to collect saliva
      samples, to measure cortisol, immediately after they wake up on the 3 testing days. Note that
      testing sessions involve pupillometry (measurement of area of pupil of the eye). This is done
      using a specialised camera pointed at the eye and is not invasive.
    

Intervention name(s): IBLT; IBLT control
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Information bias learning task-- a computer based task in which positive information is more useful when learning how best to complete it; A control version of the IBLT task-- a computer based task in which both positive and negative information is useful when learning how to complete it
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: learning