This study is a randomized, placebo-controlled, dose-ranging trial of plant-derived cannabidiol (CBD) among people who regularly use cannabis concentrates but are not trying to stop or cut down on their use. The main questions it aims to answer are whether CBD, relative to placebo, reduces cannabis concentrate use, the subjective effects of cannabis, or cannabis craving. Participants will take CBD (200 mg or 400 mg per day) or placebo for 4 weeks and will complete three visits during the study medication period, all conducted using a mobile laboratory.
The overarching aim of this proposal is to combine a naturalistic cannabis administration paradigm with a placebo-controlled, dose-ranging randomized controlled trial of plant-derived cannabidiol (CBD) to evaluate CBD effects on cannabis concentrate use, subjective effects, and cannabis cue reactivity. To achieve this aim, 120 adult frequent concentrate users will be recruited to complete a four-week protocol during which they will complete three sessions in a mobile pharmacology laboratory. Up to 200 participants may be consented/enrolled to account for screen failures and attrition. In two of the sessions, participants will use their typical cannabis concentrate on an ad libitum basis. Amount of delta-9-tetrahydrocannabinol (THC) self-administration during these sessions will be quantified by THC blood levels, obtained in the mobile lab immediately before and after use. Subjective drug effects and exogenous and endogenous cannabinoid biomarkers will also be quantified before and after THC use. Immediately after the first mobile lab session, participants will be randomly assigned to take either 200 mg or 400 mg of plant-derived, broad-spectrum CBD or matched placebo (40 participants per group) daily for four weeks. Participants will complete a second mobile lab session after two weeks to provide a blood sample that will be analyzed for cannabinoid levels. At this session, participants will also complete a cannabis cue reactivity paradigm. Participants will complete a second mobile lab session after four weeks of study medication ingestion, during which blood draws and THC self-administration will be repeated. There are three aims: Aim 1. Test the effect of CBD, relative to placebo and to baseline, on cannabis use over four weeks and THC self-administration in the mobile laboratory. Hypothesis 1a. Both doses of CBD, relative to placebo, will reduce THC metabolite levels at weeks 2 and 4. Hypothesis 1b. Both doses of CBD, relative to placebo and to baseline, will reduce the amount of THC that participants choose to consume in the mobile laboratory, as assessed by pre- vs. post-use THC blood levels. Aim 2. Test the effect of CBD, relative to placebo and to baseline, on subjective drug effects (intoxication, psychotomimetic symptoms, anxiety, and negative affect) following acute cannabis concentrate use. Hypothesis 2. Both doses of CBD, relative to placebo and to baseline, will reduce intoxication, paranoia, anxiety, and negative affect following acute use, even after controlling for between-group differences in amount of concentrate used. Aim 3. Test the effect of CBD, relative to placebo, on cannabis cue-elicited craving and evaluate whether this effect mediates CBD effects on cannabis use. Hypothesis 3a. Both doses of CBD, relative to placebo, will reduce cannabis craving. Hypothesis 3b. CBD's effect on craving at week 2 will mediate its effect on THC metabolite levels at week 4. For all aims, a linear effect of CBD dose is hypothesized, with the greatest effects in the 400 mg CBD group. Successful achievement of these aims will allow determination of an efficacious dose of CBD that reduces high-THC cannabis use, subjective drug effects, and craving, setting the stage for a subsequent RCT of plant-derived CBD to treat these outcomes in treatment-seeking high-THC cannabis concentrate users.
Participants in this Arm will take 400 mg of bsCBD daily. Participants will take medication by mouth with food in the morning and evening.
Participants in this Arm will take 200 mg of bsCBD daily. Participants will take medication by mouth with food in the morning and evening.
Participants in this Arm will take a medically inert placebo. Participants will take medication by mouth with food in the morning and evening.
University of Colorado Anschutz Medical Campus
Aurora, Colorado, United States
RECRUITINGDifference in blood 11-Nor-9-carboxy-THC (THC-COOH) levels
THC-COOH levels in blood samples collected at baseline, Week 2, and Week 4 of medication ingestion
Time frame: 4 weeks
Difference in blood delta-9-tetrahydrocannabinol (THC) levels
THC levels in blood samples collected before and after cannabis use at baseline and at Week 4 of medication ingestion
Time frame: 4 weeks
Difference in cannabis use
Total number of days of cannabis use during the 4-week medication period as reported on daily diaries
Time frame: 4 weeks
Difference in cannabis-induced intoxication
Drug Effects Questionnaire score following cannabis use at baseline and at Week 4 of medication ingestion (minimum = 0, maximum = 5, higher scores = greater intoxication)
Time frame: 4 weeks
Difference in cannabis-induced subjective effects
Addiction Research Center Inventory Marijuana score following cannabis use at baseline and at Week 4 of medication ingestion (minimum = 0, maximum = 12, higher scores = greater subjective effects)
Time frame: 4 weeks
Difference in cannabis-induced psychotomimetic symptoms
Psychotomimetic States Inventory paranoia and cognitive disorganization item scores following cannabis use at baseline and at Week 4 of medication ingestion (minimum = 0, maximum = 54, higher scores = greater psychotomimetic symptoms)
Time frame: 4 weeks
Difference in cannabis-induced anxiety and negative affect
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Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
QUADRUPLE
Enrollment
120
Profile of Mood States short form tension, vigor, and elation subscale item scores following cannabis use at baseline and at Week 4 of medication ingestion (minimum = 0, maximum = 60, higher scores = greater anxiety and negative affect)
Time frame: 4 weeks
Difference in cannabis craving
Marijuana Craving Questionnaire-Short Form score before and after the cannabis cue reactivity procedure at Week 2 of medication ingestion (minimum = 12, maximum = 84, higher scores = greater craving)
Time frame: 2 weeks