Marijuana Smoking
Conditions
Brief summary
This laboratory study will employ a multi-session experimental design to examine the behavioral economic demand for marijuana, by studying effect of marijuana administration (High THC) on demand for marijuana, and marijuana smoking topography. The study will recruit 100 non-treatment seeking marijuana users who smoke marijuana at least twice weekly.
Detailed description
This laboratory study will employ a multi-session experimental design to examine craving for marijuana, the effect of marijuana administration (High THC) on behavioral economic demand for marijuana, and marijuana smoking topography. The study will recruit 100 non-treatment seeking marijuana users who smoke marijuana at least twice weekly. The relationship between hypothetical and actual demand for marijuana will be examined. We will also investigate relationship between demand for marijuana and indices of marijuana smoking topography. The study will recruit 100 non-treatment seeking marijuana users who smoke marijuana at least twice weekly to obtain a final sample of 85 with complete data (15% of attrition). Participants will be tested at a baseline session and during two experimental sessions (an ad libitum marijuana smoking session and a marijuana smoking topography session). This study will confirm the utility of the hypothetical marijuana purchase task as a reliable and valid tool for assessing behavioral economic marijuana demand.
Interventions
DRUGSmoked marijuana cigarettes: High THC dose (6% THC)
Smoked marijuana cigarettes (High THC dose \[6% THC\])
Sponsors
Brown University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* marijuana use at least 8 times in the past month on average and at least monthly for the past 6 months * English-speaking * negative urine toxicology screen for drugs other than marijuana * non-treatment seeking * purchase of marijuana at least twice in the past 6 months to confirm familiarity with the construct to be measured
Exclusion criteria
* positive pregnancy test * nursing * inability to use contraception during the study * poor physical health * positive breath alcohol concentration * diagnosis of a current affective disorder, psychosis, and panic disorder * self-report of past serious adverse reaction to marijuana * current psychotropic drug use * smoking more than 20 tobacco cigarettes per day * inability to abstain from marijuana for 15 hours * body mass index outside 18.5-30 kg/m2 range
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Validity of the Marijuana Purchase Task (MPT) | Duration of the experimental session (i.e., 60 minutes) | The Marijuana Purchase Task will be used to collect data on marijuana demand. Participants indicate how much marijuana they would purchase at varying levels of price (e.g., free - $60). Indices of marijuana demand are derived from the task and used to determine the relative value of marijuana for each participant. Hits purchased on the MPT will correspond with actual number of hits purchased and smoked in the laboratory. Primary outcome is percentage of participants who purchased and smoked exactly what they said they would. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Marijuana Craving Questionnaire (MCQ) | The MCQ will be administered pre- and post- marijuana smoking during the experimental session, up to 6 hours | Subjective marijuana craving was assessed via a 10-item Marijuana Craving Questionnaire. Participants were asked to respond to items according to how they were thinking or feeling right now, and MCQ items were rated on a 1 = strongly disagree to 7 = strongly agree scale, with higher scores indicating greater subjective marijuana craving, and summed to yield a total craving score. Total craving score was used in analyses. |
| Marijuana Smoking Topography | Marijuana smoking topography indices will be collected during the 1-hour ad libitum marijuana smoking topography experimental session. | Indices of Marijuana Smoking Topography will be obtained during the experimental session. Participants will smoke marijuana through a smoking topography device. The outcome measure is number of puffs. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| High THC Dose (6% THC) Smoked marijuana cigarettes (High THC dose \[6% THC\])
Smoked marijuana cigarettes: High THC dose (6% THC): Smoked marijuana cigarettes (High THC dose \[6% THC\]) | 114 |
| Total | 114 |
Baseline characteristics
| Characteristic | High THC Dose (6% THC) |
|---|---|
| Age, Continuous | 26.6 years STANDARD_DEVIATION 5.4 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 20 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 94 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 10 Participants |
| Race (NIH/OMB) Black or African American | 19 Participants |
| Race (NIH/OMB) More than one race | 9 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 4 Participants |
| Race (NIH/OMB) White | 72 Participants |
| Sex: Female, Male Female | 50 Participants |
| Sex: Female, Male Male | 64 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 114 |
| other Total, other adverse events | 0 / 114 |
| serious Total, serious adverse events | 0 / 114 |
Outcome results
Primary
Validity of the Marijuana Purchase Task (MPT)
The Marijuana Purchase Task will be used to collect data on marijuana demand. Participants indicate how much marijuana they would purchase at varying levels of price (e.g., free - $60). Indices of marijuana demand are derived from the task and used to determine the relative value of marijuana for each participant. Hits purchased on the MPT will correspond with actual number of hits purchased and smoked in the laboratory. Primary outcome is percentage of participants who purchased and smoked exactly what they said they would.
Time frame: Duration of the experimental session (i.e., 60 minutes)
Population: All participants who completed Session 1 (n=101), reported purchasing at least 1 hit from a cannabis joint at their randomly selected price-point on the Marijuana Purchase Task (n=90), and chose to smoke during the Session (n=86) were included in the analysis. Outcome corresponds to percentage of participants who smoked exactly what they said they would.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| High THC Dose (6% THC) | Validity of the Marijuana Purchase Task (MPT) | 63 percentage of participants |
p-value: 4e-8Regression, Linear
Secondary
Change in Marijuana Craving Questionnaire (MCQ)
Subjective marijuana craving was assessed via a 10-item Marijuana Craving Questionnaire. Participants were asked to respond to items according to how they were thinking or feeling right now, and MCQ items were rated on a 1 = strongly disagree to 7 = strongly agree scale, with higher scores indicating greater subjective marijuana craving, and summed to yield a total craving score. Total craving score was used in analyses.
Time frame: The MCQ will be administered pre- and post- marijuana smoking during the experimental session, up to 6 hours
Population: All participants who completed Session 1 (n=101), reported purchasing at least 1 hit from a cannabis joint at their randomly selected price-point on the Marijuana Purchase Task (n=90), and chose to smoke during the Session (n=86) were included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High THC Dose (6% THC) | Change in Marijuana Craving Questionnaire (MCQ) | -0.75 units on the MCQ | Standard Deviation 1.09 |
p-value: 9e-9t-test, 2 sided
Secondary
Marijuana Smoking Topography
Indices of Marijuana Smoking Topography will be obtained during the experimental session. Participants will smoke marijuana through a smoking topography device. The outcome measure is number of puffs.
Time frame: Marijuana smoking topography indices will be collected during the 1-hour ad libitum marijuana smoking topography experimental session.
Population: Participants who completed Session 2 with usable smoking topography data.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High THC Dose (6% THC) | Marijuana Smoking Topography | 29 puffs | Standard Deviation 13.7 |
p-value: 0.87correlation