Neuroscience of Marijuana Impaired Driving (MJDriving)

Yale University

Status and phase: Completed; Phase 1

Conditions: Marijuana Impairment

Treatments: Drug: Placebo marijuana; Drug: Low dose THC marijuana; Drug: High dose THC marijuana

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT02757313

1R01DA038807-01A1 (U.S. NIH Grant/Contract)

1507016175

Details and patient eligibility

About

Marijuana is one of the most widely used substances. However, marijuana intoxication is not fully understood in relation to driving. This study will help the investigators learn more about the potential impairments related to marijuana intoxicated driving. A combination of MRI and neuropsychological tests (which are computer and paper/pencil tasks) will be used to measure intoxication and impairment. This study will also assess levels of marijuana in blood and saliva samples. This study takes place in Hartford, Connecticut.

Full description

Cannabis is a commonly abused drug whose use cuts across social class, is linked to cognitive impairment, and may be a major contributor to intoxication-related accidents - either alone or with alcohol. However, cannabis intoxication is little studied in relation to driving compared to alcohol. Not only does the current NHTSA Strategic Plan for Behavioral Research prioritize understanding how drugs other than alcohol contribute to traffic crashes, it has recently become more pressing to understand the effects of cannabis because of increasing rates of legalized medical and/or recreational use, that will likely result in more cannabis intoxicated drivers. Social and legal policy will be unable to effectively address the many concerns about driving safety raised by more frequent and widespread use of cannabis without new research to better determine the parameters within which cannabis use does, or does not, increase automobile accident risk. The purpose of this study is to better describe specific, driving-related cognitive impairments caused by acute cannabis intoxication, their persistence over time, underlying functional brain anatomy, and relationship to performance on a state-of the art validated simulated driving task in which the investigators have prior experience. In a randomized, counterbalanced, double-blinded fashion, the investigators will administer two cannabis doses and placebo of smoked cannabis (paced inhalation using a vaporizer) to 48 regular cannabis users and 48 occasional cannabis users on 3 separate occasions. Following cannabis dosing cognitive and driving impairment will be assessed longitudinally for several hours using a combination of fMRI and neuropsychological tests, to clarify relationships between subjective and objective measures of intoxication and of impairment, that include expert assessment of THC and its metabolite levels in blood and saliva. This study takes place in Hartford, Connecticut.

Enrollment: 62 patients

Sex: All

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Must have a current driver's license
• Have used marijuana before
• Right handed

Exclusion criteria

• Females who are pregnant or breast feeding
• Unable or unsafe to have an MRI
• Any serious medical, or neurological disorder
• Any psychiatric disorder
• No major head traumas

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Single Group Assignment

Masking: Quadruple Blind

---

62 participants in 2 patient groups

Regular Users

Experimental group

Description:

People who use marijuana regularly will be given a low dose THC marijuana, high dose THC marijuana and placebo marijuana, in a randomized order, at the study visits.

Treatment:

Drug: High dose THC marijuana

Drug: Low dose THC marijuana

Drug: Placebo marijuana

Occasional Users

Experimental group

Description:

People who use marijuana occasionally will be given a low dose THC marijuana, high dose THC marijuana and placebo marijuana, in a randomized order, at the study visits.

Treatment:

Drug: High dose THC marijuana

Drug: Low dose THC marijuana

Drug: Placebo marijuana