Active clinical trials for "Marijuana Abuse"

This is a double-blind within-subjects clinical laboratory study comparing the product appeal and abuse liability-related subjective effects of different flavored cigar wrappers for marijuana blunts.

The proposed 2-week, double-blind, crossover, proof of concept study aims to measure and manipulate core neurochemical (i.e., dysregulated brain GABA/glutamate homeostasis) and neurobehavioral (i.e., elevated impulsivity) dysfunctions characteristic of individuals with cannabis use disorder (CUD) and Bipolar Disorder (BD), using a medication that has been shown to increase cortical GABA (i.e., gabapentin) levels in past research, and to evaluate medication-related changes in response inhibition (go no-go) and cannabis cue reactivity functional Magnetic Resonance Imaging tasks, as well as cannabis use, mood symptoms (including anxiety and sleep), and impulsivity in individuals with CUD+BD.

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.

In this translational research proposal, based on our formulation, we seek to confirm and expand upon data obtained in our pilot study suggesting that cannabis and the cannabinoid agonist dronabinol, given in low dose to patients with schizophrenia and co-occurring cannabis use disorder, will in fact ameliorate the brain reward circuit dysregulation in these patients and, thereby, provide evidence in support of the role of cannabis as a "self-medication" agent for them.

This project has two primary goals. The first goal is to further scientific understanding about marijuana abuse by examining two recognized factors in marijuana use and relapse: (1) stress/anxiety and (2) atypical reactivity to marijuana-related stimuli (e.g., attentional bias). The second goal is to attenuate the influence of stress/anxiety and attentional bias to marijuana stimuli via administration of buspirone. Buspirone is uniquely suited to this project because it has effects on neurotransmitter systems known to modulate both stress/anxiety and attentional bias.

The primary objective of this application is to test the neurobehavioral mechanisms and effects of aprepitant as a new cessation agent for cannabis, tobacco or both.

The following study is designed to determine the analgesic efficacy of smoked marijuana (0, 1.98, and 3.56% THC) and oral THC (0, 10, and 20 mg) in the Cold-Pressor Test (CPT), a laboratory model of pain which has predictive validity for clinical use of analgesics. Oral THC (dronabinol) is known to have a slower onset and longer duration of action compared with smoked marijuana. Therefore, the analgesic effects of oral THC is expected to peak later and last longer than effects produced by smoked marijuana.

The objective of this study is to investigate the interaction between marijuana and quetiapine, with the goal of using this information to improve marijuana treatment outcome.

Background: The therapeutic modalities of cannabis have received more research attention recently with the discovery of its ability to stimulate appetite and to provide pain and nausea relief in patients with AIDS, cancer, and multiple sclerosis, among other diseases. Sativex(Registered Trademark), an experimental drug derived from the marijuana plant, contains tetrahydrocannabinol (THC) and cannabidiol (CBD), both of which affect brain activity. Sativex(Registered Trademark) is being tested to determine how and to what extent it affects brain activity. Functional magnetic resonance imaging (fMRI) uses magnetic waves to study brain activity. Researchers are interested in using fMRI to study how Sativex(Registered Trademark) affects regional brain activity, including thinking abilities and behavior. Objectives: To study changes in regional brain activity produced by Sativex(Registered Trademark) compared with THC and placebo. To determine how Sativex(Registered Trademark) is processed by the body. Eligibility: - Individuals between 18 and 45 years of age who are either current users of cannabis (less than daily) or healthy volunteers who do not use cannabis. Design: The study will involve one training session and five testing sessions on separate days. At every session, subjects will receive either THC or placebo capsules and either Sativex(Registered Trademark) or placebo spray. Participants will complete a training session in a mock fMRI scanner to adapt to the fMRI scanning environment. In the training session, participants will practice the tests that will track thinking ability, attention, working memory, and other cognitive tasks. Participants will have five fMRI scanning sessions with the tests they have practiced previously, and will provide blood, urine, and saliva samples as required by the researchers. Participants will be discharged approximately 12 hours after they arrive for the study sessions....

Background: Rimonabant, a CB1 receptor antagonist, blocks effects of cannabinoids and, in dependent animals, elicits cannabinoid withdrawal. No studies have examined rimonabantelicited cannabis withdrawal in humans. Goals: (1) Determine the lowest single dose of oral rimonabant that elicits measurable cannabinoid withdrawal. (2) Characterize cognitive performance, subjective state, physiological condition, and regional brain activation (measured by functional magnetic resonance imaging [fMRI]) during acute and chronic administration of oral delta 9-tetrahydrocannabinol (THC) and during cannabis withdrawal. (3) Characterize the pharmacokinetics of oral THC and metabolites in body fluids and hair and of rimonabant in plasma. Subject Population: Up to 60 completing cannabis users aged 18-45 (up to 24 in Experiment I, 36 in Experiment II) and 18 completing non-drug-using controls (Experiment II). Enrollment target is 82% Caucasian, 14% African American, 4% other; 9% Hispanic; 35% women. Experimental Design and Methods: Experiment I: In this within-subject, randomized, double-blind, dose-escalation study, six participants receive 7 days of THC (40-120 mg/day). On Day 8, five participants receive 20 mg rimonabant; one receives placebo. If withdrawal criteria (greater than or equal to 150% or 2.5-fold increase in selected visual-analog scales) are not met in all five participants receiving rimonabant, separate groups of six are similarly treated with 40, 60 or 80 mg rimonabant, if necessary. The PI and MRP will submit all adverse events and relevant cardiovascular and scientific data to the IRB at the completion of each rimonabant dose panel. When the extramural NIDA DSMB is in place, it will review all data collected to date and develop and implement a monitoring plan, including review on completion of each dose cohort. DSMB recommendations will be reviewed by the Sponsor, Clinical Director and IRB before proceeding to the next dose cohort. In addition, if any subject has an intolerable adverse event (ie, an adverse event leading to study discontinuation) or serious adverse event in response to rimonabant on Day 8, the blind for that subject will be broken, and a report sent to the Sponsor, the extramural NIDA DSMB when in place and the IRB for discussion. Experiment II: In this randomized, placebo-controlled, double-blind study, 36 participants receive 7 days of THC (40-120 mg/day). On Day 8, 18 participants receive rimonabant dose determined in Experiment I to elicit cannabis withdrawal; 18 participants receive placebo rimonabant to evaluate spontaneous cannabis withdrawal. Cognitive, psychological, physiological and hormonal measures are monitored to determine onset, magnitude, and duration of THC intoxication and withdrawal and to correlate with THC and rimonabant pharmacokinetics. Changes in blood oxygen level-dependent (BOLD) signal are determined with five fMRI scans throughout the study. Eighteen non-drug-using controls undergo scanning and cognitive testing at similar intervals. Risks and Benefits: The proposed doses of THC and rimonabant have been well tolerated in other studies. The most common side effects of oral THC are sedation, cognitive impairment, euphoria, poor coordination, tachycardia, and hypotension. Spontaneous withdrawal from cannabis is mild and medically benign. Experience with other drugs suggests that antagonist-elicited cannabis withdrawal may have an earlier onset and greater intensity than spontaneous cannabis withdrawal. There are no clinical benefits to participants. Scientific benefits are greater understanding of cannabis intoxication, tolerance, and withdrawal and of the role of rimonabant in eliciting cannabis withdrawal.