Pramipexole and Emotional Processing
Condition: Emotions; Motivation; Reward; Dopamine
Study type: Interventional

Summary: 
      The dopamine agonist pramipexole has recently been suggested as a potential novel
      antidepressant drug. While preliminary clinical data hint at its efficacy in treating
      depressive symptoms, our current understanding of its impact on neurocognitive processes is
      relatively limited. This is in part because mechanistic studies have largely focused on the
      effects of single-dose treatments. However, such acute administration of dopaminergic drugs
      likely has different cognitive effects than the more prolonged administration that is used
      clinically. This study therefore aims to explore and characterise the neurocognitive effects
      of more prolonged pramipexole treatment. Forty healthy volunteers will be randomly allocated
      to 12 to 15 days of treatment with either pramipexole or placebo. Study participants as well
      as researchers will be blinded as to which treatment is used. Before and after treatment all
      participants will perform a set of psychological tasks and questionnaires evaluating
      reward-based learning, emotional information processing, motivational vigour and subjective
      experience. Furthermore, functional magnetic resonance imaging (fMRI) will be used to compare
      neural activity during emotion and reward processing between the two treatment groups. We
      hypothesises that pramipexole might enhance reward sensitivity, motivational vigour, and
      pleasure experience and could induce positive biases in emotional information processing.
    

Detailed description: 
      Background:

      The dopamine receptor agonist pramipexole has recently been suggested as a potential novel
      antidepressant drug. While preliminary clinical data hint at its efficacy in treating
      depressive symptoms, our current understanding of its impact on neurocognitive processes is
      relatively limited. This is in part because, so far, mechanistic studies have largely focused
      on the effects of single-dose treatments. However acute administration of dopaminergic drugs
      likely has different cognitive effects than the more prolonged administration that is used
      clinically.

      Aim of study:

      To explore and characterise the effects of a 12 to 15 day regime of pramipexole on
      behavioural and neural measures of reward learning, emotional information processing,
      motivational invigoration, and subjective experience.

      Methods:

      Using a double-blind, parallel-group design, forty healthy volunteers (male and female, aged
      18 to 45 years) will be randomly allocated to a 12 to 15 day regime of either pramipexole
      (maximum daily dose of 1.0 mg pramipexole salt) or placebo. At baseline and after 12 to 15
      days of treatment, a set of previously established cognitive tasks and questionnaires tapping
      into reward learning, emotional information processing, motivational invigoration and
      subjective experience will be administered. Furthermore, at 12 to 15 days of treatment, all
      participants will undergo functional magnetic resonance imaging to compare neural responses
      to reward- and emotion-related information.

      Hypotheses:

      Our working hypothesis is that pramipexole will enhance reward sensitivity, motivational
      invigoration and hedonic experience and might positively bias emotional information
      processing.

      Implications:

      This will be the first study to broadly explore and characterise the neurocognitive effects
      of pramipexole administered for a clinically relevant time period. The results of the study
      will add to our understanding of the cognitive mechanisms through which pramipexole could
      exert both its beneficial as well as its adverse clinical effects.
    

Intervention name(s): Pramipexole; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): Pramipexole; Lactose placebo capsule
Intervention MeSH terms: Pramipexole
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Basic Science
Keywords: Pramipexole