Alcohol Drinking, Opioid Use, Unspecified
Conditions
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.
Interventions
DRUGNaltrexone
Naltrexone is an opioid antagonist with primary action at the mu opioid receptor.
OTHERPlacebo
Placebo will be used to control for expectancy effects
Sponsors
University of Colorado, Denver
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Masking description
capsule, double blind
Intervention model description
Participants will be counterbalanced for the order they undergo placebo and medication.
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Brain Activation to Reward Between Placebo and Active Medication | 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
| Measure | Time frame | Description |
|---|---|---|
| Alcohol Value | one week | Maximum alcohol expenditure, or Omax, is the maximum amount of money that a person will pay for alcohol in a hypothetical alcohol consumption task called the Alcohol Purchase Task. Higher values of Omax indicate that a person values consuming alcohol at a greater level. |
| Brain Activation to Emotion Regulation | one week | Percent signal change from baseline in the amygdala during trials to regulate emotion relative to trials to passively experience emotion during a functional MRI scan. Cues will be negative images, and instructions will be either decrease or look. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Healthy Adults: Placebo First This arm will receive placebo first, then active medication second
Naltrexone: Naltrexone is an opioid antagonist with primary action at the mu opioid receptor.
Placebo: Placebo will be used to control for expectancy effects | 6 |
| Healthy Adults: Active Medication First This arm will receive active medication first, then placebo second
Naltrexone: Naltrexone is an opioid antagonist with primary action at the mu opioid receptor.
Placebo: Placebo will be used to control for expectancy effects | 5 |
| Total | 11 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Withdrawal by Subject | 1 | 1 |
Baseline characteristics
| Characteristic | Healthy Adults: Placebo First | Healthy Adults: Active Medication First | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 6 Participants | 5 Participants | 11 Participants |
| Age, Continuous | 24.8 years STANDARD_DEVIATION 4.4 | 24.0 years STANDARD_DEVIATION 4.4 | 24.2 years STANDARD_DEVIATION 4.6 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 6 Participants | 5 Participants | 11 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 6 Participants | 5 Participants | 11 Participants |
| Region of Enrollment United States | 6 participants | 5 participants | 11 participants |
| Sex: Female, Male Female | 5 Participants | 3 Participants | 8 Participants |
| Sex: Female, Male Male | 1 Participants | 2 Participants | 3 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 11 | 0 / 11 |
| other Total, other adverse events | 0 / 11 | 0 / 11 |
| serious Total, serious adverse events | 0 / 11 | 0 / 11 |
Outcome results
Primary
Change in Brain Activation to Reward Between Placebo and Active Medication
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.
Time frame: one week
Population: The participants who completed the study were analyzed. They were all healthy adults who met inclusion/exclusion criteria.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Naltrexone | Change in Brain Activation to Reward Between Placebo and Active Medication | 0.25 percentage signal change | Standard Deviation 0.09 |
| Placebo | Change in Brain Activation to Reward Between Placebo and Active Medication | 0.26 percentage signal change | Standard Deviation 0.1 |
Secondary
Alcohol Value
Maximum alcohol expenditure, or Omax, is the maximum amount of money that a person will pay for alcohol in a hypothetical alcohol consumption task called the Alcohol Purchase Task. Higher values of Omax indicate that a person values consuming alcohol at a greater level.
Time frame: one week
Population: Healthy adults who completed the study
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Naltrexone | Alcohol Value | 19.4 Dollars | Standard Deviation 14.8 |
| Placebo | Alcohol Value | 19.9 Dollars | Standard Deviation 17.4 |
Secondary
Brain Activation to Emotion Regulation
Percent signal change from baseline in the amygdala during trials to regulate emotion relative to trials to passively experience emotion during a functional MRI scan. Cues will be negative images, and instructions will be either decrease or look.
Time frame: one week
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Naltrexone | Brain Activation to Emotion Regulation | 0.1 percentage signal change | Standard Deviation 0.1 |
| Placebo | Brain Activation to Emotion Regulation | 0.1 percentage signal change | Standard Deviation 0.1 |