Cannabis Effects on Driving-related Skills of Young Drivers

• Status: Completed
• Trial end date: 2016-09-01
• Target enrollment: 0
• Participant gender: All

Summary

Motor vehicle collisions are the leading cause of death for young people. The investigators have recently found that driving after using cannabis is more common among young Canadian drivers than driving after drinking. While this observation raises concerns, the effects of cannabis on driving-related skills in this age group are not well understood. As well, evidence suggests that residual effects of cannabis on driving-related skills may be observed up to 24 hours later. These residual effects may have important implications for the effects of cannabis use on collision risk, but little evidence on them in available. This study will examine the effects of a single dose of cannabis (marijuana) on driving-related skills immediately following consumption, 24 hours later, and 48 hours later. To date, the residual effect at 48 hours has not been examined. A total of 142 subjects aged 19 to 25 years old will be randomly assigned to smoke either a placebo or active cannabis cigarette (12.5% THC potency). Following an eligibility screening and practice session, participants will attend 3 testing days; drug-administration, 24-hour follow-up and 48-hour follow-up. The effects of cannabis/placebo on performance of driving-related skills using a high-fidelity driving simulator will be assessed on each testing day. The effects of cannabis on mood, cognition, memory and complex reaction time will also be assessed. Identifying factors that affect the collision risks experienced by young drivers is a public health priority. While many young people believe that cannabis does not impair driving, some recent studies suggest that these may be very dangerous beliefs. This study will provide important information on how cannabis may affect the driving skills of young drivers, to inform efforts to understand and address cannabis-related collision in this age group.

• Phase: N/A
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Centre for Addiction and Mental Health
• Collaborators: Canadian Institutes of Health Research (CIHR); Health Canada
• Treatments: Dronabinol

Criteria

Inclusion Criteria:

• Males and females aged 19 to 25

• Regular cannabis users (between one and four times per week)

• Held a valid class G or G2 Ontario driver's license (or equivalent from another jurisdiction) for at least 12 months.

• Willing to abstain from cannabis use for the duration of the study, and for 48 hours prior to Session 2.

• Provides written and informed consent

• Urine toxicology result positive for THC (indicating recent use of cannabis).

Exclusion Criteria:

• Positive breathalyzer results for alcohol on any given study day.

• Is a regular user of medications that affect brain function (i.e., antidepressants, benzodiazepines, stimulants).

• Diagnosis of severe medical or psychiatric conditions.

• A first degree relative diagnosed with schizophrenia.

• Meets criteria for current or lifetime Substance Use Disorders (DSM-IV) with the exception of nicotine.

• Meets criteria for Cannabis Dependence (DSM-IV).

• Is pregnant, is trying to become pregnant, or is currently breastfeeding.

Ongoing Exclusion Criteria:

• Upon eligibility assessment, toxicology results indicate that the participant has not used cannabis recently.

• Any toxicology screen after Session 2 - Practice Day indicating a psychoactive substance has been used other than cannabis.