Marijuana Use Disorder
Conditions
Keywords
Cannabinoids, Risk taking, Decision making
Brief summary
The purpose of this study is to investigate the effects of smoked marijuana on both risk taking and decision making tasks.
Detailed description
Cannabis abuse and dependence are the most prevalent drug use disorders in the United States (Compton et al., 2004), yet little is known about the factors contributing to successful marijuana treatment. Previously, we have shown that cognitive impairments in patients treated for substance disorders are associated with premature treatment dropout. However, little is known about whether such impairments are the result of drug use per se. The objective of this within-subject study is to determine whether decision-making and risk-taking are affected by acute cannabis intoxication. The Balloon Analogue Risk Task (BART; Lejuez et al. 2002) assesses decision making in a context of increasing risk, and the Iowa Gambling Task (IGT; Bechara et al. 1994) tests the ability to balance immediate rewards against long-term negative consequences; both tasks have strong face validity for evaluating cognitive deficits that may contribute to poor treatment outcome. Research volunteers will be current marijuana smokers. Each will participate in three, 4-hour outpatient sessions in the Substance Use Research Center (SURC) in the Division of Substance Abuse at NYSPI. They will smoke a different strength marijuana cigarette (0.0, 1.98, 3.9% THC) in each session in counter-balanced order. After baseline data have been collected (risk taking and decision making behaviors, heart rate, blood pressure, mood scales, exhaled carbon monoxide), participants will take 3-6 puffs, 5 seconds in duration, from a National Institute on Drug Abuse (NIDA) marijuana cigarette. After smoking, we will repeatedly re-assess risk taking and decision making abilities with the BART and IGT. We will also measure subjective mood ratings, heart rate and blood pressure repeatedly for 180 minutes following smoking. This study is the first controlled investigation of the effects of smoked marijuana on both risk taking and decision making tasks. The data obtained will be used to guide treatment development for marijuana use disorders.
Interventions
Placebo marijuana was administered using a cued-smoking procedure, which produces reliable increases in heart-rate and plasma THC. All marijuana cigarettes were administered in a double-blind fashion.
DRUGLow THC marijuana (1.8 %THC)
Active marijuana (1.8 % THC) was administered using a cued-smoking procedure, which produces reliable increases in heart-rate and plasma THC. All marijuana cigarettes were administered in a double-blind fashion.
DRUGHigh THC marijuana (3.9% THC)
Active marijuana (3.9%) was administered using a cued-smoking procedure, which produces reliable increases in heart-rate and plasma THC. All marijuana cigarettes were administered in a double-blind fashion.
Sponsors
National Institute on Drug Abuse (NIDA)
New York State Psychiatric Institute
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Masking description
Double-blind, placebo-controlled
Eligibility
Sex/Gender
ALL
Age
21 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Current marijuana use * 21-45 years of age * Practicing an effective form of birth control * Not seeking treatment for marijuana use
Exclusion criteria
* Current, repeated illicit drug use other than marijuana * Presence of significant medical illness (e.g., diabetes, cardiovascular disease, hypertension) * Laboratory tests outside normal limits that are clinically unacceptable to the study physician (BP \> 140/90; hematocrit \< 34 for women, \< 36 for men) * Significant adverse reaction to marijuana * Current parole or probation * Pregnancy or current lactation * Recent history of significant violent behavior * Major current Axis I psychopathology (e.g., mood disorder with functional impairment or suicide risk, anxiety disorder, schizophrenia * History of heart disease * Current use of any over-the-counter or prescription medication from which the volunteer cannot be withdrawn
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Iowa Gambling Task Scores [Objective Measure of Decision Making] | 3 weeks | A modified version of the Gambling Task (Bechara et al., 1994) was used. Four decks of cards (A-D) were displayed on a computer screen. Volunteers were told that the objective of the game was to win as much money as possible. They were also told that the game entailed a series of card selections from any of the decks, one card at a time, and that they should select cards until instructed to stop. The task was stopped after 100 card selections or after 5 min had elapsed. Data indicate change from baseline in mean number of cards selected from advantageous decks minus number of cards selected from disadvantageous decks as a function of drug condition. Higher numbers indicate better decision making regarding advantageous cards. Planned comparisons using single degrees of freedom, generated by a two-tailed repeated measures analysis of variance (ANOVA), were used to examine the effects of THC concentration (0% vs. 1.8%, 0% vs. 3.9%, and 1.8% vs. 3.9%) on task performance. |
Countries
United States
Participant flow
Recruitment details
A total of 36 healthy research volunteers completed this three-session, within-subject outpatient study. Drug treatment was randomized.
Participants by arm
| Arm | Count |
|---|---|
| Total Sample A total of 36 participants completed the study | 36 |
| Total | 36 |
Baseline characteristics
| Characteristic | Total Sample |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 36 Participants |
| Age, Continuous | 25.4 years STANDARD_DEVIATION 4 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 13 Participants |
| Race (NIH/OMB) More than one race | 2 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 21 Participants |
| Region of Enrollment United States | 36 Participants |
| Sex: Female, Male Female | 16 Participants |
| Sex: Female, Male Male | 20 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 36 | 0 / 36 | 0 / 36 |
| other Total, other adverse events | 0 / 36 | 0 / 36 | 0 / 36 |
| serious Total, serious adverse events | 0 / 36 | 0 / 36 | 0 / 36 |
Outcome results
Primary
Change From Baseline in Iowa Gambling Task Scores [Objective Measure of Decision Making]
A modified version of the Gambling Task (Bechara et al., 1994) was used. Four decks of cards (A-D) were displayed on a computer screen. Volunteers were told that the objective of the game was to win as much money as possible. They were also told that the game entailed a series of card selections from any of the decks, one card at a time, and that they should select cards until instructed to stop. The task was stopped after 100 card selections or after 5 min had elapsed. Data indicate change from baseline in mean number of cards selected from advantageous decks minus number of cards selected from disadvantageous decks as a function of drug condition. Higher numbers indicate better decision making regarding advantageous cards. Planned comparisons using single degrees of freedom, generated by a two-tailed repeated measures analysis of variance (ANOVA), were used to examine the effects of THC concentration (0% vs. 1.8%, 0% vs. 3.9%, and 1.8% vs. 3.9%) on task performance.
Time frame: 3 weeks
Population: All participants who completed the study (N=36) were included in the final analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Inactive Marijuana (0%THC) | Change From Baseline in Iowa Gambling Task Scores [Objective Measure of Decision Making] | 3.7 mean number of cards | Standard Deviation 0.8 |
| Low Dose Marijuana (1.8% THC) | Change From Baseline in Iowa Gambling Task Scores [Objective Measure of Decision Making] | 10.1 mean number of cards | Standard Deviation 3.4 |
| High Dose Marijuana (3.9% THC) | Change From Baseline in Iowa Gambling Task Scores [Objective Measure of Decision Making] | 4.4 mean number of cards | Standard Deviation 2.1 |