Opioid Modulation and Neural Reward Activation in Healthy Adults
Trial Snapshot
- Phase
- Phase 1
- Status
- Completed
- Enrollment
- 13
- Locations
- 1
- Primary Endpoint
- Change in Brain Activation to Reward Between Placebo and Active Medication
Study Overview
Brief Summary
This is a double blind study of the effects of opioid antagonism on the brain's reward response. The investigators will recruit participants to undergo two scans, one on active medication and one on placebo. During the scan, the investigators will assess reward.
Detailed Description
The study will employ a crossover design. The study will use the monetary incentive delay task during functional MRI to assess reward. This task presents participants with cues indicating whether they are playing to win $5, win $0, or to avoid losing $5. This task has been well-validated to elicit activation in a key reward response area of the brain called the ventral striatum.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Basic Science
- Masking
- Triple (Participant, Investigator, Outcomes Assessor)
Masking Description
capsule, double blind
Eligibility Criteria
- Ages
- 18 Years to 35 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Between 18 and 35 years of age,
- •Is a moderate drinker (i.e. consumes 1-14 drinks/week for males, or 1-7 drinks/week for females).
Exclusion Criteria
- •Non-drinker
- •Positive result on urine drug screen or breathalyzer at the start of any study visit
- •Inability to complete MRI (e.g. presence of ferromagnetic objects in body)
- •Current use of medications that alter the hemodynamic response such as insulin
- •History of trauma resulting in loss of consciousness longer than 15 minutes
- •Currently taking opioid medications
- •Pregnancy
Arms & Interventions
Naltrexone, Then Placebo
Participants first received naltrexone capsules each day in a blister pack for 5 days. Days 1 and 2 were at 25mg/day, and days 3-5 were at 50mg/day. After a washout period of at least 3 days, they then received placebo capsules (matching naltrexone capsules) for 5 days.
Intervention: Placebo (Other)
Placebo, Then Naltrexone
Participants first received placebo capsules each day in a blister pack for 5 days. After a washout period of at least 3 days, they then received naltrexone capsules (matching placebo capsules) at 25mg/day for days 1 and 2 and then 50mg/day for days 3-5 for 5 days.
Intervention: Naltrexone (Drug)
Placebo, Then Naltrexone
Participants first received placebo capsules each day in a blister pack for 5 days. After a washout period of at least 3 days, they then received naltrexone capsules (matching placebo capsules) at 25mg/day for days 1 and 2 and then 50mg/day for days 3-5 for 5 days.
Intervention: Placebo (Other)
Naltrexone, Then Placebo
Participants first received naltrexone capsules each day in a blister pack for 5 days. Days 1 and 2 were at 25mg/day, and days 3-5 were at 50mg/day. After a washout period of at least 3 days, they then received placebo capsules (matching naltrexone capsules) for 5 days.
Intervention: Naltrexone (Drug)
Outcomes
Primary Outcomes
Change in Brain Activation to Reward Between Placebo and Active Medication
Time Frame: one week
Percent signal change relative to baseline in the nucleus accumbens during cue to win $5 as assessed during functional MRI. Higher values of percent signal change indicate greater activation to reward. We will compare the active medication condition to the placebo, establishing whether there is a difference between the conditions.
Secondary Outcomes
- Alcohol Value(one week)
- Brain Activation to Emotion Regulation(one week)