Cannabis Impairment Detection Application (CIDA)
Condition: Driving Under the Influence; Marijuana Intoxication; Alcohol Intoxication
MeSH terms: Marijuana Abuse; Alcoholic Intoxication
Study type: Interventional

Summary: 
      Subjects will participate in a 4-visit study protocol in which they will be asked to complete
      a set of computerized tasks and a 45-minute simulated drive in a driving simulator. Subjects
      will be administered marijuana of varying pre-determined concentrations of
      delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) during 3 of the visits and alcohol
      during one of the visits. Throughout the duration of each visit, brain activity will be
      measured noninvasively using an electroencephalogram (EEG) headset.

      The purpose of this study is to:

        1. Further understand the effects of acute cannabis intoxication on driving performance in
           a driving simulator

        2. Develop and refine brain-based biomarkers of impairment due to acute cannabis
           intoxication
    

Detailed description: 
      At the University of Iowa, subjects who currently use cannabis recreationally (> once a month
      but < 5 times a week) will be recruited. They will then undergo a screening visit in which
      consent is obtained, questionnaires are given, and a physical exam is administered. They will
      then be scheduled for their next 3 (or 4 if participating in the alcohol arm), which will be
      at least one week apart. At each visit, in counter-balanced manner, subjects will be
      administered 500 mg of either placebo Marijuana (trace amounts of THC), high THC marijuana
      (7.5%), or very high THC marijuana (12.5%). All marijuana will be inhaled ad libitum via a
      Volcano® Digit vaporizer. Additionally, a subset of subjects will be asked to complete a
      fourth study visit that administers alcohol in place of cannabis. As subjects complete the
      third study visit and meet criteria for the alcohol arm, they will be invited to participate
      in the fourth study visit until eighteen subjects complete the study's alcohol arm. After
      drug administration, subjects will be asked to complete a set of computerized neurocognitive
      tasks (1 hour), followed by a simulated drive (45 minutes).

      Throughout the duration of each visit, EEG will be collected. EEG is a non-invasive method of
      recording the electrical activity of the brain. Additionally, blood draws will be taken at
      pre-determined time points.

      Finally, subjects will be monitored until the drug effects have subsided sufficiently to
      ensure it is safe to transport them home. Subjects will be transported home.
    

Intervention name(s): Cannabis (THC) (Inhaled) Placebo; Cannabis (High% THC) (Inhaled); Cannabis (Very High% THC) (Inhaled); Alcohol (oral)
Intervention type(s): Drug; Drug; Drug; Drug
Intervention description(s): Cannabis vapor is produced from 500 mg of dried plant material (placebo) (0% THC). Participants will inhale ad libitum over 10 minutes.; Cannabis vapor is produced from 500 mg of dried plant material (7.5% THC). Participants will inhale ad libitum over 10 minutes.; Cannabis vapor is produced from 500 mg of dried plant material (12.5% THC). Participants will inhale ad libitum over 10 minutes.; Subjects will be dosed to achieve a 0.05% Blood Alcohol Concentration (BAC), so the amount of alcohol consumed will be calculated to produce a peak BAC of 0.065%. Subjects will be served three equal-sized drinks, 10-minutes apart, and be instructed to pace each drink evenly over the 10-minute period.
Other intervention name(s): Marihuana; Marijuana; Marihuana; Marijuana; Marihuana; Marijuana; Ethanol; Ethyl Alcohol
Intervention MeSH terms: Ethanol
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: The University of Iowa study is a counter-balanced dose-response protocol where all participants will receive all three doses of marijuana (plus alcohol if they qualify).
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Basic Science
Keywords: Marijuana; Cannabis; Alcohol; Driving; DUI; Drinking behavior; Substance Use; Driving Impairment; Drugs; EEG; SDLP