An interventional study of delta-9-tetrahydrocannabinol and Placebo in Psychomotor Impairment, sponsored by Centre for Addiction and Mental Health. Completed at 1 site in Canada. Open to participants aged 19 Years to 25 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2019-02-11.
Sponsored by Centre for Addiction and Mental Health · Not applicable, Interventional, and Basic science
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.
This study will test the prediction that residual effects of an acute dose of cannabis on driving-related skills will be observed in a group of young drivers 48 hours following a single dose of smoked cannabis, and will also examine the effects of an acute dose of cannabis on those skills using driving simulator technology.
Study Objectives
Study Design and Duration
The study is a double-blind, placebo-controlled mixed-design study, including a randomized between-subjects comparison of the effects of smoked cannabis and both between- and within-subjects examination of its residual effects at 24 and 48 hours following one-time drug administration. Although a placebo condition is part of the study, this is not a treatment study.
Initial contact with potential subjects will be made via telephone, and study personnel will conduct a telephone screen for eligibility. Upon eligibility confirmation by telephone, participants will be asked to attend CAMH for an eligibility assessment. The study will consist of 5 sessions for each subject (an eligibility assessment, a practice day, and three subsequent testing days). Participants will be asked not to use cannabis for 48 hours prior to attending the practice day (Session 2). Although Session 1 can be completed at any time prior to the remaining study sessions, Sessions 2 - 5 must be performed on consecutive days.
In certain instances, the Qualified Investigator may ask a participant to return for re-screening, e.g. repeat of urine test or other assessments performed for eligibility assessment. Also, in case of unforeseen delays in scheduling study participation, the Qualified Investigator will determine if there is a need to ask a participant to repeat some assessments, e.g., physical examination.
20 studies on the registry are indexed under Psychomotor Disorders; 6 are open to participants now.
This study's enrollment of 99 is above the median of 49 across 15 interventional studies indexed under Psychomotor Disorders.
Browse Psychomotor Disorders studies →Centre for Addiction and Mental Health is the lead sponsor of 327 studies on the registry; 51 are open to participants now.
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Exclusion Criteria:
Ongoing Exclusion Criteria:
In this condition, participants will receive a cigarette containing 12.5% active THC.
Drug: delta-9-tetrahydrocannabinol
In this condition, participants will receive a cannabis cigarette where the active THC has been removed (contains 0% THC).
Drug: Placebo
A single cannabis cigarette (potency 12.5% THC) will be given to participants to smoke over a 10 minute period, ad lib. If the cigarette is not smoked in its entirety, the remainder will be weighed to estimate dose.
Also known as: cannabis sativa, marijuana
A single placebo cannabis cigarette (0% THC) will be given to participants to smoke over a 10 minute period, ad lib. If the cigarette is not smoked in its entirety, the remainder will be weighed to estimate dose (as this is a double-blind study).
Also known as: cannabis sativa, marijuana
Psychomotor Impairment (Driving)
The driving simulator will objectively measure driving behaviour during a number of pre-programmed driving scenarios. Zone/ Hazard performance measure: Mean Speed.
Time frame: Approximate: at baseline (30 minutes before smoking), 30 minutes after smoking
Recruitment was by media ads and research postings in Toronto.
| Milestone | Active Cannabis | Placebo |
|---|---|---|
| Started | 67 | 32 |
| Completed | 67 | 31 |
| Not completed | 0 | 1 |
| Withdrew: Withdrawal by subject | 0 | 1 |
The driving simulator will objectively measure driving behaviour during a number of pre-programmed driving scenarios. Zone/ Hazard performance measure: Mean Speed.
| change in kph | Active Cannabis | Placebo |
|---|---|---|
| Psychomotor Impairment (Driving) | 3.38 ± 9.75 | -1.54 ± 7.36 |
Collected over Collected from session 1 (eligibility assessment) to session 2 (practice) (approx. 3 months); from session 2 to 3 (approx. 24 hours), from session 3 to 4 (approx. 24 hours), session 4 to session 5 (approx. 24 hours).. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Active Cannabis | 0/67 (0%) | 0/67 (0%) | 38/67 (56.7%) |
| Placebo | 0/32 (0%) | 0/32 (0%) | 15/32 (46.9%) |
| Event | Active Cannabis | Placebo |
|---|---|---|
| headacheGeneral disorders | 10/67 | 2/32 |
| tiredness/fatigueGeneral disorders | 5/67 | 3/32 |
| insomniaGeneral disorders | 6/67 | 0/32 |
| dizziness/faintnessGeneral disorders | 5/67 | 2/32 |
| injuryMusculoskeletal and connective tissue disorders | 0/67 | 2/32 |
| anxiety/nervousnessPsychiatric disorders | 1/67 | 2/32 |
| muscle/bone/joint painMusculoskeletal and connective tissue disorders | 3/67 | 2/32 |
| simulation sicknessEar and labyrinth disorders | 1/67 | 2/32 |
| low blood pressureVascular disorders | 4/67 | 1/32 |
| rashSkin and subcutaneous tissue disorders | 4/67 | 0/32 |
One participant was excluded from analyses because they admitted to having tried to skew their data. They withdrew from the study.
| Age, Continuous(years) | Active Cannabis | Placebo | Total |
|---|---|---|---|
| Mean | 22.22 ± 1.88 | 21.97 ± 2.24 | 22.14 ± 1.995 |
| Sex: Female, Male(Participants) | Active Cannabis | Placebo | Total |
|---|---|---|---|
| Female | 19 | 9 | 28 |
| Male | 48 | 22 | 70 |
| Region of Enrollment(participants) | Active Cannabis | Placebo | Total |
|---|---|---|---|
| Canada | 67 | 31 | 98 |
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Centre for Addiction and Mental Health