Trial Outcomes & Findings for Dopamine Responsivity in Gamblers (NCT NCT02772978)

NCT ID: NCT02772978

Last Updated: 2021-02-16

Results Overview

The presented value represents a correlation. Subjects completed a delay discounting task while functional MRI images were obtained. In this task, subjects made hypothetical choices between a smaller amount of money available sooner, and a larger amount of money available later. Performance on the delay discounting task, as assessed by the impulsive choice ratio, was determined for both the tolcapone and placebo sessions, and the difference between them (tolcapone minus placebo) was calculated. This difference value was then correlated with scores on the Barratt Impulsiveness Scale, non-planning subscale.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

19 participants

Primary outcome timeframe

120 minutes after drug ingestion

Results posted on

2021-02-16

Participant Flow

Patients were recruited from the community between June 2014 and September 2015.

Participant milestones

Participant milestones
Measure
Functional MRI Arm - Tolcapone, Then Placebo
This cognitive science study consists of a single "arm" in which all subjects receive both tolcapone and placebo in randomized, double-blind, counterbalanced, crossover fashion Tolcapone: Tolcapone is in the medication class of catechol-O-methyltransferase (COMT) inhibitors Placebo: A placebo is a tablet or capsule that looks like the study medication (in this case, tolcapone) but does not contain any active ingredients
Functional MRI Arm - Placebo, Then Tolcapone
This cognitive science study consists of a single "arm" in which all subjects receive both tolcapone and placebo in randomized, double-blind, counterbalanced, crossover fashion Tolcapone: Tolcapone is in the medication class of catechol-O-methyltransferase (COMT) inhibitors Placebo: A placebo is a tablet or capsule that looks like the study medication (in this case, tolcapone) but does not contain any active ingredients
Overall Study
STARTED
10
9
Overall Study
COMPLETED
9
8
Overall Study
NOT COMPLETED
1
1

Reasons for withdrawal

Reasons for withdrawal
Measure
Functional MRI Arm - Tolcapone, Then Placebo
This cognitive science study consists of a single "arm" in which all subjects receive both tolcapone and placebo in randomized, double-blind, counterbalanced, crossover fashion Tolcapone: Tolcapone is in the medication class of catechol-O-methyltransferase (COMT) inhibitors Placebo: A placebo is a tablet or capsule that looks like the study medication (in this case, tolcapone) but does not contain any active ingredients
Functional MRI Arm - Placebo, Then Tolcapone
This cognitive science study consists of a single "arm" in which all subjects receive both tolcapone and placebo in randomized, double-blind, counterbalanced, crossover fashion Tolcapone: Tolcapone is in the medication class of catechol-O-methyltransferase (COMT) inhibitors Placebo: A placebo is a tablet or capsule that looks like the study medication (in this case, tolcapone) but does not contain any active ingredients
Overall Study
Withdrawal by Subject
1
1

Baseline Characteristics

Dopamine Responsivity in Gamblers

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Functional MRI Arm
n=17 Participants
This cognitive science study consists of a single "arm" in which all subjects receive both tolcapone and placebo in randomized, double-blind, counterbalanced, crossover fashion Tolcapone: Tolcapone is in the medication class of catechol-O-methyltransferase (COMT) inhibitors Placebo: A placebo is a tablet or capsule that looks like the study medication (in this case, tolcapone) but does not contain any active ingredients
Age, Continuous
31.5 years
STANDARD_DEVIATION 8.9 • n=99 Participants
Sex: Female, Male
Female
6 Participants
n=99 Participants
Sex: Female, Male
Male
11 Participants
n=99 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=99 Participants
Race (NIH/OMB)
Asian
6 Participants
n=99 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=99 Participants
Race (NIH/OMB)
Black or African American
0 Participants
n=99 Participants
Race (NIH/OMB)
White
10 Participants
n=99 Participants
Race (NIH/OMB)
More than one race
1 Participants
n=99 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=99 Participants
Region of Enrollment
United States
17 Participants
n=99 Participants
Barratt Impulsiveness Scale, Non-planning Subscale
25.6 units on a scale
STANDARD_DEVIATION 4.7 • n=99 Participants

PRIMARY outcome

Timeframe: 120 minutes after drug ingestion

Population: The outcome for this study was the correlation between the BIS score, non-planning subscale, and the difference in ICR (tolcapone minus placebo). As such, one Arm/Group is presented below.

The presented value represents a correlation. Subjects completed a delay discounting task while functional MRI images were obtained. In this task, subjects made hypothetical choices between a smaller amount of money available sooner, and a larger amount of money available later. Performance on the delay discounting task, as assessed by the impulsive choice ratio, was determined for both the tolcapone and placebo sessions, and the difference between them (tolcapone minus placebo) was calculated. This difference value was then correlated with scores on the Barratt Impulsiveness Scale, non-planning subscale.

Outcome measures

Outcome measures
Measure
Functional MRI Arm (Tolcapone and Placebo)
n=17 Participants
This cognitive science study consists of a single arm in which all subjects receive both tolcapone and placebo in randomized, double-blind, counterbalanced, crossover fashion. Tolcapone is a medication in the class of catechol-O-methyltransferase (COMT) inhibitors. A placebo is a tablet or capsule that looks like the study medication (in this case, tolcapone) but does not contain any active ingredients.
Correlation Between the Impulsive Choice Ratio and Baseline Impulsivity, as Measured With the Barratt Impulsiveness Scale, Non-planning Subscale
-0.5 Correlation coefficient

OTHER_PRE_SPECIFIED outcome

Timeframe: 120 minutes after drug ingestion

Population: The outcome for this study was the correlation between the difference in the ICR and the difference in BOLD activity (tolcapone minus placebo). As such, one Arm / Group is presented below.

The presented value represents a correlation. The difference in performance on the delay discounting task was calculated as the change in ICR (tolcapone minus placebo). In addition, the difference in BOLD activity throughout the brain was determined (tolcapone minus placebo).

Outcome measures

Outcome measures
Measure
Functional MRI Arm (Tolcapone and Placebo)
n=17 Participants
This cognitive science study consists of a single arm in which all subjects receive both tolcapone and placebo in randomized, double-blind, counterbalanced, crossover fashion. Tolcapone is a medication in the class of catechol-O-methyltransferase (COMT) inhibitors. A placebo is a tablet or capsule that looks like the study medication (in this case, tolcapone) but does not contain any active ingredients.
Correlation Between the Difference in ICR (Tolcapone Minus Placebo) and the Difference in Blood Oxygen Level Dependent (BOLD) Signal in the Brain (Tolcapone Minus Placebo)
-0.76 Correlation coefficient

Adverse Events

Tolcapone Arm

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Placebo Arm

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Andrew Kayser, MD PhD

University of California at San Francisco

Phone: 415-502-7332

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place