Risky Decision Making in Methamphetamine Users: The Role of Opioid Blockade

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.

Study Overview

• Status: Completed
• Conditions: HIV; Methamphetamine Abuse
• Intervention / Treatment: Drug: Placebo; Drug: Extended release naltrexone

• Study Type: Interventional
• Enrollment (Actual): 76
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Oregon
    • Portland, Oregon, United States, 97239
      • Oregon Health & Science University
    • Portland, Oregon, United States, 97239
      • Portland VA Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 55 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Summary Inclusion Criteria:

• Diagnostic and Statistical Manual (DSM)-IV Methamphetamine Dependence
• Deemed healthy enough to participate by study physician
• Age 18-55
• Right handed
• English-speaking

Summary Exclusion Criteria:

• Current opioid use in the last 30 days; opioid abuse or dependence within past 5 years
• Pregnancy
• MRI contraindications (e.g. metal in head).

The research is conducted in Portland, OR.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Extended release naltrexone; One dose of intramuscular injection of 380mg extended-release naltrexone.	Drug: Extended release naltrexone; Other Names: Vivitrol
Placebo Comparator: Placebo; One dose of intramuscular injection of placebo.	Drug: Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Discounting Tasks: Sexual Probability Discounting (SexPD)	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.	28 days post drug intervention
Discounting Tasks: Standard Delay Discounting (DD)	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).	28 days post drug intervention
Barrat Impulsiveness Scale (BIS)	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.	28 days post drug intervention
Risk Assessment Battery (RAB)	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.	28 days post drug intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Methamphetamine Use	Participants were asked "How many days in the past 30 days did you use methamphetamine?". This is a self-report measure.	28 days post drug intervention

Collaborators and Investigators

• Sponsor: Oregon Health and Science University
• Collaborators: National Institute on Drug Abuse (NIDA)

Publications and helpful links

General Publications

• Kohno M, Morales AM, Dennis LE, McCready H, Hoffman WF, Korthuis PT. Effects of Naltrexone on Large-Scale Network Interactions in Methamphetamine Use Disorder. Front Psychiatry. 2019 Sep 3;10:603. doi: 10.3389/fpsyt.2019.00603. eCollection 2019.
• Kohno M, Dennis LE, McCready H, Schwartz DL, Hoffman WF, Korthuis PT. A preliminary randomized clinical trial of naltrexone reduces striatal resting state functional connectivity in people with methamphetamine use disorder. Drug Alcohol Depend. 2018 Nov 1;192:186-192. doi: 10.1016/j.drugalcdep.2018.07.045. Epub 2018 Sep 21.

Study record dates

Study Major Dates

• Study Start: May 1, 2013
• Primary Completion (Actual): March 1, 2015
• Study Completion (Actual): March 1, 2015

Study Registration Dates

• First Submitted: March 21, 2013
• First Submitted That Met QC Criteria: March 27, 2013
• First Posted (Estimate): April 2, 2013

Study Record Updates

• Last Update Posted (Actual): March 5, 2019
• Last Update Submitted That Met QC Criteria: February 12, 2019
• Last Verified: February 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Peripheral Nervous System Agents; Sensory System Agents; Narcotic Antagonists; Alcohol Deterrents; Naltrexone
• Other Study ID Numbers: ALKIIT-KOR-034; 1R21DA033182-01A1 (U.S. NIH Grant/Contract)