Trial Outcomes & Findings for Neurobehavioral Mechanisms of Choice in Opioid Use Disorder (NCT NCT03958474)
NCT ID: NCT03958474
Last Updated: 2026-07-02
Results Overview
Subjects completed a 300-trial probabilistic concurrent monetary choice task, also known as an n-bandit task (here, n=2 choice options, with unsigned probability reversals every 50 trials). In each trial, subjects chose between two options signaled by blue and green envelopes. When a reward was scheduled for the chosen option, subjects were notified they earned $0.25 USD; task earnings were provided upon session completion. Choice of the high probability option was more likely to be reinforced than the low probability option at a 6:1 ratio, with probabilities summing to 0.3, resulting in a low reinforcement density context. Because choosing the higher probability option is associated with a higher likelihood of receiving a monetary reinforcer, making more high probability choices is considered better performance on the task.
Recruitment status
COMPLETED
Study phase
EARLY_PHASE1
Target enrollment
12 participants
Primary outcome timeframe
Subjects complete the task twice; once under opioid maintained and once under opioid withdrawn conditions during a 16-day inpatient participation. The task takes approximately 20 minutes to complete each time.
Results posted on
2026-07-02
Participant Flow
Participant milestones
| Measure |
Active Oxycodone and Placebo
Participants complete a probabilistic money-vs-money choice task during opioid maintained and opioid withdrawn conditions. Opioid withdrawal is accomplished via double-blind substitution of placebo for active oxycodone in daily maintenance capsules.
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|---|---|
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Overall Study
STARTED
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12
|
|
Overall Study
COMPLETED
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12
|
|
Overall Study
NOT COMPLETED
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Neurobehavioral Mechanisms of Choice in Opioid Use Disorder
Baseline characteristics by cohort
| Measure |
Active Oxycodone and Placebo
n=12 Participants
Participants complete a probabilistic money-vs-money choice task during opioid maintained and opioid withdrawn conditions. Opioid withdrawal is accomplished via double-blind substitution of placebo for active oxycodone in daily maintenance capsules.
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|---|---|
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Age, Continuous
|
33.6 years
STANDARD_DEVIATION 6.8 • n=20 Participants
|
|
Sex: Female, Male
Female
|
6 Participants
n=20 Participants
|
|
Sex: Female, Male
Male
|
6 Participants
n=20 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
0 Participants
n=20 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
12 Participants
n=20 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=20 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=20 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=20 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=20 Participants
|
|
Race (NIH/OMB)
Black or African American
|
1 Participants
n=20 Participants
|
|
Race (NIH/OMB)
White
|
11 Participants
n=20 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=20 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=20 Participants
|
|
Region of Enrollment
United States
|
12 participants
n=20 Participants
|
PRIMARY outcome
Timeframe: Subjects complete the task twice; once under opioid maintained and once under opioid withdrawn conditions during a 16-day inpatient participation. The task takes approximately 20 minutes to complete each time.Subjects completed a 300-trial probabilistic concurrent monetary choice task, also known as an n-bandit task (here, n=2 choice options, with unsigned probability reversals every 50 trials). In each trial, subjects chose between two options signaled by blue and green envelopes. When a reward was scheduled for the chosen option, subjects were notified they earned $0.25 USD; task earnings were provided upon session completion. Choice of the high probability option was more likely to be reinforced than the low probability option at a 6:1 ratio, with probabilities summing to 0.3, resulting in a low reinforcement density context. Because choosing the higher probability option is associated with a higher likelihood of receiving a monetary reinforcer, making more high probability choices is considered better performance on the task.
Outcome measures
| Measure |
Oxycodone
n=12 Participants
Subjects complete a probabilistic money-vs-money choice task during oxycodone maintenance.
Oxycodone: Participants receive oxycodone or placebo.
|
Withdrawal
n=12 Participants
Subjects complete a probabilistic money-vs-money choice task during opioid withdrawal induced via double-blind substitution of placebo for active oxycodone in maintenance capsules.
Oxycodone: Participants receive oxycodone or placebo.
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|---|---|---|
|
Probabilistic Money vs Money Choice Task
|
198.2 Number high probability option choices
Standard Deviation 15.3
|
191.2 Number high probability option choices
Standard Deviation 16.5
|
Adverse Events
Oxycodone
Serious events: 0 serious events
Other events: 8 other events
Deaths: 0 deaths
Withdrawal
Serious events: 0 serious events
Other events: 11 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
Oxycodone
n=12 participants at risk
Subjects complete a probabilistic money-vs-money choice task during oxycodone maintenance.
Oxycodone: Participants receive oxycodone or placebo.
|
Withdrawal
n=12 participants at risk
Subjects complete a probabilistic money-vs-money choice task during opioid withdrawal induced via double-blind substitution of placebo for active oxycodone in maintenance capsules.
Oxycodone: Participants receive oxycodone or placebo.
|
|---|---|---|
|
Nervous system disorders
Yawning
|
8.3%
1/12 • Number of events 1 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
33.3%
4/12 • Number of events 4 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Psychiatric disorders
Anxiety
|
16.7%
2/12 • Number of events 2 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
58.3%
7/12 • Number of events 7 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Cardiac disorders
Elevated heart rate (>100 bpm)
|
0.00%
0/12 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
25.0%
3/12 • Number of events 3 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Skin and subcutaneous tissue disorders
Sweating
|
8.3%
1/12 • Number of events 1 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
91.7%
11/12 • Number of events 11 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Musculoskeletal and connective tissue disorders
Restlessness
|
8.3%
1/12 • Number of events 1 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
66.7%
8/12 • Number of events 8 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Eye disorders
Pupil dilation
|
66.7%
8/12 • Number of events 8 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
91.7%
11/12 • Number of events 11 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Musculoskeletal and connective tissue disorders
Bone and joint aches
|
16.7%
2/12 • Number of events 2 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
75.0%
9/12 • Number of events 9 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Respiratory, thoracic and mediastinal disorders
Runny nose
|
33.3%
4/12 • Number of events 4 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
83.3%
10/12 • Number of events 10 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Gastrointestinal disorders
Stomach cramps
|
16.7%
2/12 • Number of events 2 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
50.0%
6/12 • Number of events 6 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Gastrointestinal disorders
Diarrhea
|
0.00%
0/12 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
8.3%
1/12 • Number of events 1 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Musculoskeletal and connective tissue disorders
Tremor
|
16.7%
2/12 • Number of events 2 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
75.0%
9/12 • Number of events 9 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
|
Skin and subcutaneous tissue disorders
Piloerection
|
8.3%
1/12 • Number of events 1 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
50.0%
6/12 • Number of events 6 • On each of the two days that choice task data were collected.
Udvalg for Kliniske Undersøgelser Side Effect Rating Scale Clinical Opiate Withdrawal Scale
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place