Risky Decision Making in Methamphetamine Users: The Role of Opioid Blockade
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|ClinicalTrials.gov Identifier: NCT01822132|
Recruitment Status : Completed
First Posted : April 2, 2013
Results First Posted : February 6, 2019
Last Update Posted : March 5, 2019
The purpose of this protocol is to learn more about impulsive decision making in people who use methamphetamines. The investigators would like to know if a medication called naltrexone changes how people make decisions. The investigators would also like to know whether changes in decision making can be observed by MRI (magnetic resonance imaging).
The research is conducted in Portland, OR.
|Condition or disease||Intervention/treatment||Phase|
|Methamphetamine Abuse HIV||Drug: Extended release naltrexone Drug: Placebo||Not Applicable|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||76 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Triple (Participant, Care Provider, Investigator)|
|Official Title:||Risky Decision Making in Methamphetamine Users: The Role of Opioid Blockade|
|Study Start Date :||May 2013|
|Actual Primary Completion Date :||March 2015|
|Actual Study Completion Date :||March 2015|
Experimental: Extended release naltrexone
One dose of intramuscular injection of 380mg extended-release naltrexone.
Drug: Extended release naltrexone
Other Name: Vivitrol
Placebo Comparator: Placebo
One dose of intramuscular injection of placebo.
- Discounting Tasks: Sexual Probability Discounting (SexPD) [ Time Frame: 28 days post drug intervention ]
In the SexPD task, subjects are asked to choose between having sex with a more appealing partner with a varying chance of having a sexually transmitted infection (STI) or a less appealing partner with no STI.
A hyperbolic decay model was used to calculate h, a free parameter that indexes the rate of probabilistic discounting. Smaller h values indicate a preference for probabilistic (i.e., riskier) outcomes. To normalize the data, the natural log of h values were calculated and reported here.
- Discounting Tasks: Standard Delay Discounting (DD) [ Time Frame: 28 days post drug intervention ]Monetary delay discounting task consisted of choosing between a larger, delayed and a smaller, immediate reward. A hyperbolic decay model was used to calculate k, a free parameter that indexes the rate of delay discounting. As k values are typically skewed across subjects, the distribution of k was normalized by using a natural log transformation. The normalized values are reported here. If k typically ranges between 0.5 and 10^-5, then the natural log of k will range between -0.69 and -11.5. Larger normalized k values indicate a preference for smaller sooner outcomes (i.e., more impulsive decision-making).
- Barrat Impulsiveness Scale (BIS) [ Time Frame: 28 days post drug intervention ]The Barrat Impulsiveness Scale (BIS) is a 30 item questionnaire to measure a persons impulsiveness. Items are answered on a 4-point scale and scored 1-4 then summed across responses. Total scores range from 30-120 with a higher summed score indicating higher impulsivity.
- Risk Assessment Battery (RAB) [ Time Frame: 28 days post drug intervention ]
The Risk Assessment Battery (RAB) is a 26 question self-administered assessment focusing on drug use, injection and sexual risk during the past 30 days.
Three composite HIV risk scores (drug, sex, and total score) are calculated. The questions have different numbers of items, and scores for a single question can range from 0 to 7, with higher values reflecting more instances of risk behavior. The drug risk score has a range of 0 to 22 and is calculated from 8 questions that address recent substance use, including frequency, needle sharing, and cleaning of the "works." 9 questions are used to calculate a sex risk score that has a range of 0 to 18, and these questions address the frequency and types of sexual behavior, HIV status of sexual partners, and type of protection that was used (if any). Total score is calculated by adding drug and sex scores and dividing by 40, the maximum score possible, and ranges from 0 to 40 where higher scores indicate greater risk behavior.
- Methamphetamine Use [ Time Frame: 28 days post drug intervention ]Participants were asked "How many days in the past 30 days did you use methamphetamine?". This is a self-report measure.
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 ClinicalTrials.gov identifier (NCT number): NCT01822132
|United States, Oregon|
|Oregon Health & Science University|
|Portland, Oregon, United States, 97239|
|Portland VA Medical Center|
|Portland, Oregon, United States, 97239|
|Principal Investigator:||Philip T Korthuis, MD, MPH||Oregon Health and Science University|