Dose-response of Cannabis and Driving

Center for Addiction and Mental Health (CAMH)

Status and phase: Completed; Phase 2

Conditions: Abuse Cannabis; Cognitive Impairment; Driving Impaired

Treatments: Drug: Placebo; Drug: Cannabis

Study type: Interventional

Funder types: Other

Identifiers

NCT03656029

007-2018

Details and patient eligibility

About

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.

Full 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.

Enrollment: 36 patients

Sex: All

Ages: 19 to 45 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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36 participants in 4 patient groups, including a placebo group

Placebo

Placebo Comparator group

Description:

Participants will smoke a single smoked placebo (\<0.1% THC) cannabis cigarette

Treatment:

Drug: Placebo

low dose

Active Comparator group

Description:

Participants will smoke a single low dose (6.25% THC) of smoked cannabis cigarette

Treatment:

Drug: Cannabis

middle dose

Active Comparator group

Description:

Participants will smoke a single intermediate dose (12.5% THC) of smoked cannabis cigarette

Treatment:

Drug: Cannabis

high dose

Active Comparator group

Description:

Participants will smoke a single high dose (22% THC) of smoked cannabis cigarette

Treatment:

Drug: Cannabis