Neuroscience of Marijuana Impaired Driving
Condition: Marijuana Impairment
MeSH terms: Marijuana Abuse
Study type: Interventional
Phase: Phase 1

Summary: 
      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.
    

Detailed 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.
    

Intervention name(s): Low dose THC marijuana; High dose THC marijuana; Placebo marijuana
Intervention type(s): Drug; Drug; Drug
Other intervention name(s): THC, cannabis; THC, cannabis; THC, cannabis
Intervention MeSH terms: Dronabinol
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Other
Keywords: marijuana; driving; THC; cannabis; intoxication; MRI