Dose-dependent Effects of Smoked Cannabis on Simulated Driving Performance
Overview
- Phase
- Phase 2
- Intervention
- Placebo
- Conditions
- Driving Impaired
- Sponsor
- Centre for Addiction and Mental Health
- Enrollment
- 36
- Locations
- 1
- Primary Endpoint
- Mean speed
- Status
- Completed
- Last Updated
- 3 years ago
Overview
Brief Summary
Epidemiological studies have established a link between collisions while driving and cannabis use. With the changing legal landscape around cannabis, there is much interest in determining per se limits of cannabis while driving. The present study will evaluate driving on a driving simulator after smoking placebo or cannabis with 3 different levels of THC. THC is the active component in cannabis and blood, urine and oral fluid levels of THC will be correlated with driving impairment.
Detailed Description
Participants will attend the laboratory for 4 separate sessions, separated by about a week. In each session, participants will receive one of 3 doses of smoked cannabis or a placebo. Participants will not know which dose they are receiving. Participants will complete questionnaires, do cognitive tests and drive on a driving simulator before and after smoking the cannabis or placebo cigarette. Blood, urine and oral fluid will be collected throughout the 7-8 hour session to determine levels of THC and its metabolites. These values will be correlated with measures of driving impairment.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Near daily use of cannabis (1-5 days/week) confirmed by self-report and urine screening
- •Has held a class G2 or G licence (or equivalent from another jurisdiction) for at least 12 months
- •Willing to abstain from using cannabis for 72 hours prior to each practice or test session
- •Willing to abstain from alcohol for 48 hours prior to each session, and to abstain from all other drugs not medically required for the duration of the study (beginning 48 hours prior to the practice session)
- •Provides written and informed consent
Exclusion Criteria
- •Diagnosis of severe medical or psychiatric condition
- •Meets criteria for current or lifetime alcohol or other substance use disorder, except tobacco use disorder and caffeine use disorder
- •Regular user of medication that may affect cognitive functioning and/or driver performance
- •Family history of schizophrenia or other psychotic disorder
- •Pregnant, looking to become pregnant, or breastfeeding
Arms & Interventions
Placebo
Participants will smoke a single smoked placebo (\<0.1% THC) cannabis cigarette
Intervention: Placebo
low dose
Participants will smoke a single low dose (6.25% THC) of smoked cannabis cigarette
Intervention: Cannabis
middle dose
Participants will smoke a single intermediate dose (12.5% THC) of smoked cannabis cigarette
Intervention: Cannabis
high dose
Participants will smoke a single high dose (22% THC) of smoked cannabis cigarette
Intervention: Cannabis
Outcomes
Primary Outcomes
Mean speed
Time Frame: Change in speed of driving between the time before smoking the cigarette and either 30 or 90 minutes after smoking the cigarette
Speed of driving the simulator
Secondary Outcomes
- Blood concentrations of THC and metabolites(Change from before smoking cigarette to various time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours)
- Heart rate(Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours)
- Respirations(Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours)
- Verbal free recall test(Change from pre-smoking levels to those observed 60 minutes after smoking)
- Standard deviation of lateral position(Change in measure from before smoking the cigarette to either 30 or 90 minutes after smoking)
- reaction time(Change in measure from before smoking the cigarette to either 30 or 90 minutes after smoking)
- Temperature(Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours)
- Useful field of view(Change from pre-smoking levels to those observed 60 minutes after smoking)
- Oral fluid concentrations of THC and metabolites(Change from levels before smoking to 4 time points after smoking: 30 minutes, 90 minutes, 2 hours and 6 hours)
- Systolic and Diastolic Blood pressure(Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours)
- Visual Analog Scales(Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours)