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Dopamine Neurotransmission in Major Depression

NCT01659814 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 71

Last updated 2014-04-23

No results posted yet for this study

Summary

The overall aim of this study is to utilize an integrative research model in order to dynamically assess reward-related dopamine (DA) transmission in major depressive disorder (MDD) and test the role of dysfunctional DA release in depression and anhedonia.

The first arm of this line of research (PET scan) aims to investigate phasic DA release in MDD during incentive motivation. The investigators will utilize an established molecular imaging technique to measure striatal DA release dynamically during performance of testing and control versions of a monetary incentive delay task, which involves anticipation and receipt of monetary rewards. In doing so, this experiment will link together independent lines of research that have associated depression with decreased hedonic responsiveness, impaired reinforcement learning and dysfunctional DA transmission. We hypothesize that, relative to matched controls, unmedicated MDD subjects will show reduced reward-related ligand (11C-raclopride) displacement. Reduced ligand displacement will be interpreted as indicating reduced task-induced release of endogenous striatal DA in response to reward-predicting cues and unpredictable reward in MDD subjects.

In the second arm of this research (EEG recording), the investigators aim to probe the spatio-temporal dynamics of brain mechanisms underlying positive and negative reinforcement learning in MDD and their relations to phasic DA. Participants will perform the probabilistic stimulus selection task (PSST) while event-related potentials (ERPs) are collected. The investigators expect that, relative to matched controls, unmedicated MDD subjects will show reduced positive reinforcement learning, potentiated negative reinforcement learning, and larger (i.e., more negative) feedback-related negativity (FRN) in response to positive reinforcement (indicative of reduced DA transmission). Moreover, the investigators hypothesize that a more negative FRN in response to positive reinforcement will be associated with decreased striatal raclopride displacement (i.e., lower release of endogenous DA) as measured by PET in the first part of the study. This experiment will investigate the effects of blunted DA transmission on behavioral and ERP markers of both positive and negative reinforcement learning.

Conditions

Sponsors & Collaborators

  • Mclean Hospital

    lead OTHER

Principal Investigators

  • Diego Pizzagalli, PhD · Mclean Hospital

Eligibility

Min Age
18 Years
Max Age
45 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2011-03-31
Primary Completion
2012-12-31
Completion
2012-12-31

Countries

  • United States

Study Locations

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Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT01659814 on ClinicalTrials.gov