Clinical Trial: Depression and Dopamine Transporter Function Study Using C-11 Altropane

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Depression and Dopamine Transporter Function: A Positron Emission Tomography Study Using C-11 Altropane

Brief Summary:

Major depressive disorder (MDD) is often characterized by anhedonia and impaired ability to modulate behavior as a function of rewards. However, the neurobiology of anhedonia and reduced reward responsiveness remains largely unknown. Because dopamine (DA) plays a critical role in goal-directed behavior and reinforcement learning, DA dysregulation might play an important role. In fact, several lines of evidence suggest that down-regulation of DA transmission might characterize depression vulnerability and the emergence of depressive symptoms. The current study seeks to elucidate the role of DA dysfunction in MDD. We hypothesize that MDD subjects will show reduced DAT binding potential, reduced reward learning in the probabilistic reward task, and abnormal functional magnetic resonance imaging (fMRI) activation in dorsal and ventral striatal regions during an instrumental learning task.

This study will include three sessions.

The first will take place at Massachusetts General Hospital or at McLean Hospital's Center for Depression, Anxiety and Stress Research. The aims of this session will be to (a) explain the study; (b) collect written informed consent, and (c) assess the subject's eligibility.

Following this, another session (either second or third in order) will take place at the MGH PET Imaging Laboratory. Participants will complete a PET scan and a probabilistic reward task designed to measure reward learning and sensitivity to reward. The radioactive tracer utilized is 11C-altropane.

Another session (either second or third in order) will take place at the McLean Hospital Neuroimaging Center. Participants will complete an instrumental learning task while in the fMRI, followed by a social reinforcement learning task and an

Detailed Summary:
Sponsor: Mclean Hospital

Current Primary Outcome:

• 11C-Altropane Binding [ Time Frame: 1 hour long PET scan during session 2 ]
  11C-altropane binding is recording during the positron emission tomography (PET) scan and is used to measure dopamine transporter levels.
• Behavioral Performance in Probabilistic Reward Task [ Time Frame: 20 minute task administered during session 2 ]
  The probabilistic reward task is designed to measure sensitivity to reward and reward learning.
• Brain Activity during Instrumental Learning Task [ Time Frame: 30 minute long fMRI scan during session 3 ]
  Functional magnetic resonance imaging (fMRI) data are acquired while participants perform the instrumental learning task. fMRI data allows us to measure aspects of brain activity.
• Behavioral Performance in Instrumental Learning Task [ Time Frame: 30 minute task administered during session 3 ]
  The instrumental learning task is designed to measure participant learning from reward and punishment.
• Behavioral Performance in the Social Reinforcement Learning Task [ Time Frame: 15 minute task administered during session 3 ]
  The social reinforcement learning task is designed to investigate whether learning deficits in MDD are specific to learning from monetary incentives or whether the learning deficits are more global and are affected when learning from social rewards and punishments.

Original Primary Outcome: Same as current

Current Secondary Outcome:

• Questionnaire Data [ Time Frame: Self-report measures are administered at all 3 sessions which take place within an average of 2-3 weeks ]
  At all sessions participants will fill out self-report questionnaires regarding aspects of mood and affect, demographics, caffeine and alcohol consumption, etc.
• Behavioral Performance in Implicit Learning Serial Reaction Time Task [ Time Frame: 5 minute task administered during session 3 ]
  The implicit learning serial reaction time task is designed to exclude the possibility of global learning deficits in major depressive disorder.

Original Secondary Outcome: Same as current

Information By: Mclean Hospital

Dates:
Date Received: October 2, 2012
Date Started: January 2012
Date Completion:
Last Updated: April 6, 2015
Last Verified: April 2015