NCT03655717

Using Imaging to Assess Effects of THC on Brain Activity

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 316 (actual)
• Sponsor: Massachusetts General Hospital · Academic / Other
• Sex: All
• Age: 18 Years – 55 Years
• Healthy volunteers: Accepted

Summary

This study will assess effects of tetrahydrocannabinol (THC) and THC + alcohol in marijuana users on prefrontal brain activity, using functional near-infrared spectroscopy (fNIRS) during resting state and during memory task performance. Participants will complete fNIRS testing 120 minutes following THC or identical placebo (Phase 2A), or THC/ethanol, THC/placebo ethanol, placebo THC/ethanol, and placebo THC/placebo ethanol (Phase 2B), and oxygenated hemoglobin (HbO) concentration will be measured.

Detailed description

This study will assess the effects of THC intoxication using dronabinol (synthetic THC) on the oxyhemoglobin (HbO) signal during resting state and task-based activation in the prefrontal cortex (PFC) and resting state connectivity, as well as on neurocognitive task performance and correlations between these measurements and clinical signs of intoxication. Participants will be 150 adults who use marijuana at least monthly (aged 18-55) will be recruited to participate in this study. Participants will be given up to 80 mg of dronabinol, an FDA-approved synthetic form of THC that is used to treat loss of appetite that causes weight loss in people with AIDS. THC is the principle psychoactive drug in marijuana. The study will be conducted in regular cannabis users who present at their first study visit with a positive urine screen for THC metabolites. Phase 2A. Investigate the effect of THC on fNIRS brain signature and its association with self-reported intoxication, laboratory measures of impairment, and the gold-standard behavioral field test of driving impairment used by law enforcement, the primary classifier. Phase 2B. Examine potential interaction following co-administration of THC with oral ethanol exposure in healthy volunteers. Phase II is a randomized, double-blind, placebo-controlled, 2 by 2 crossover study of effect of dronabinol, ethanol, and combined dronabinol and ethanol on brain activation and connectivity as measured by fNIRS.

Conditions

• Intoxication Alcohol
• Intoxication THC
• Intoxication Combined Alcohol THC

Interventions

Type	Name	Description
DRUG	Dronabinol	Dronabinol at physician determined doses of 10-80mg designed to produce intoxication.
DRUG	Ethanol	Oral Ethanol, dosed to obtain a breath alcohol concentration (BrAC) of approximately 0.05 BrAC (equal to 1-2 standard drinks).
DRUG	Placebo dronabinol	Identical in appearance to active dronabinol (overencapsulation of both active and placebo dronabinol)
DRUG	Placebo ethanol	Placebo ethanol will consist of diet soda used in the active ethanol condition with 0.25ml ethanol floated on top to provide the odor of ethanol and blind the study drug.

Timeline

• Start date: 2018-11-05
• Primary completion: 2021-01-21
• Completion: 2021-01-21
• First posted: 2018-08-31
• Last updated: 2022-07-28
• Results posted: 2022-07-28

Locations

1 site across 1 country: United States