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Dopamine and Opioid Receptor Antagonists Reduce Cue-induced Reward Responding and Reward Impulsivity

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02557984
Recruitment Status : Completed
First Posted : September 23, 2015
Last Update Posted : September 23, 2015
Information provided by (Responsible Party):
University of Zurich

Brief Summary:
The purpose of this study is to determine how the dopamine and opioid system is involved in reward processing, specifically in cue-induced reward responding and reward impulsivity, using dopamine and opioid receptor antagonists in healthy participants. The investigators predict that particularly the dopamine challenge should alter cue-induced reward responding and reward impulsivity. Such effects would be of high interest for the treatment of disorders which involve impairments of reward processing such as addiction.

Condition or disease Intervention/treatment Phase
Addiction Drug: Placebo Drug: Amisulpride Drug: Naltrexone Not Applicable

Detailed Description:

In this study the investigators use amisulpride and naltrexone to elucidate what function the dopamine and opioid system have in the processing of reward. Amisulpride [Solian®; sanofi-aventis] is an atypical antipsychotic and acts as an antagonist at dopamine D2 and D3 (D2/D3) receptors with very high specificity. Amisulpride has been used in numerous past studies to study the role of dopamine in the brain, for example in studies on reinforcement learning, memory, and attentional bias in stimulant dependence. Naltrexone [Naltrexin®; OrPha Swiss GmbH] is an opioid antagonist and is clinically used in the management of alcohol and opioid dependence. It has been used to investigate the role of opioid in pain perception, taste detection and recognition, and smoking behavior. The investigators were interested in particular how amisulpride and naltrexone influence cue-induced reward responding and reward impulsivity.

Study Aims

A) Investigating the role of the dopamine system in cue-induced reward responding; B) Investigating the role of the dopamine system in reward impulsivity; C) Investigating the role of the opioid system in cue-induced reward responding; A) Investigating the role of the opioid system in reward impulsivity.

Study Design

This is a double-blind, randomized, placebo-controlled, between-subject blocker study. 121 participants received either placebo, the dopamine D2/D3 receptor antagonist amisulpride (400 mg), or the unselective opioid receptor antagonist naltrexone (50 mg), 3h before the experimental tasks. Subjective effects on mood were assessed by visual analogue scales (VAS). Cue-induced reward responding was measured using a standard Pavlovian-to-Instrumental Transfer (PIT) task, where participants press a button for reward in the presence of a stimulus predicting that reward. Reward impulsivity was measured using a Delay Discounting (DD) Task, in which participants choose between smaller, immediate rewards and larger, delayed rewards.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 121 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Official Title: Dopamine D2/3- and μ-opioid Receptor Antagonists Reduce Cue-induced Reward Responding and Reward Impulsivity in Healthy Volunteers
Study Start Date : February 2014
Actual Primary Completion Date : April 2014
Actual Study Completion Date : April 2014

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Placebo Comparator: Placebo
Placebo Pill
Drug: Placebo
Placebo Pill
Other Name: Lactose Placebo Pill

Experimental: Amisulpride
400 mg Amisulpride (Solian®)
Drug: Amisulpride
400 mg Amisulpride
Other Name: Solian

Experimental: Naltrexone
50 mg Naltrexone (Naltrexin®)
Drug: Naltrexone
50 mg Naltrexone
Other Name: Naltrexin

Primary Outcome Measures :
  1. Cue-Induced Reward Responding Measure [ Time Frame: 1 day ]
    Measured using a Pavlovian-to-Instrumental Transfer Task

  2. Reward Impulsivity Measure [ Time Frame: 1 day ]
    Measured using a Delay Discounting Task

Secondary Outcome Measures :
  1. Mood [ Time Frame: 1 day ]
    Current Mood assessed by Visual Analog Scale (VAS)

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 35 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Physically and psychiatrically healthy men and women

Exclusion Criteria:

  • Serious past brain disease or injury
  • Pacemaker or neurostimulator
  • Hearing aid
  • Surgery to head or heart
  • Potential metal parts in body (metal splinters, gun wounds, shrapnel or surgical clips)
  • Neurological or psychiatric problems (including alcoholism, depression, schizophrenia, bipolar disorders, anxiety disorder, claustrophobia, or parkinsonian symptoms)
  • High blood pressure, low blood pressure, cardiac attack in anamnesis, irregular heart rate
  • Epilepsy
  • Emphysema, chest problems, or multiple sclerosis
  • Respiratory problems (including difficulty breathing through the nose)
  • Pregnancy, nursing, or planning pregnancy
  • Diabetes
  • Acute Hepatitis
  • Allergy or sensitivity to lactose
  • Allergy or sensitivity to amisulpride or naltrexone
  • Breast cancer or current tumors
  • Insufficiency of liver or kidney
  • Past use of opiates or other drugs that may interact with amisulpride or naltrexone (such as stimulants)
  • Currently taking medications known to interact with amisulpride or naltrexone (including medicines used to treat irregular heart rhythm such as quinidine, disopyramide, amiodarone and sotalol, cisapride, antibiotics such as erythromycin and pentamidine, levodopa, thioridazone (an antipsychotic), or methadone)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02557984

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University Hospital
Zurich, Switzerland, 8091
Sponsors and Collaborators
University of Zurich
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Principal Investigator: Boris B Quednow, Prof University Hospital of Psychiatry Zurich
Principal Investigator: Philippe N Tobler, Prof Laboratory for Social and Neural Systems Research, Department of Economics, University of Zurich

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Responsible Party: University of Zurich Identifier: NCT02557984    
Other Study ID Numbers: SNS_Study_01
First Posted: September 23, 2015    Key Record Dates
Last Update Posted: September 23, 2015
Last Verified: September 2015
Keywords provided by University of Zurich:
Additional relevant MeSH terms:
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Impulsive Behavior
Alcohol Deterrents
Narcotic Antagonists
Physiological Effects of Drugs
Sensory System Agents
Peripheral Nervous System Agents
Antipsychotic Agents
Tranquilizing Agents
Central Nervous System Depressants
Psychotropic Drugs
Dopamine Antagonists
Dopamine Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Antidepressive Agents, Second-Generation
Antidepressive Agents