Comparing 4 approaches for driving under the influence
Official title: Combined and Separate Effects of Cannabis and Tobacco: Psychomotor, Subjective and Physiological Outcomes
- 4 groups
- One site, in Toronto
- Recruiting
Interventions (4)
- Medication
Cannabis
Dried flower cannabis cigarette with 22% THC
- Medication
Tobacco
Dried flower cigarette with active nicotine
- Medication
Cannabis tobacco
Dried flower cigarette with active nicotine and cannabis
- Medication
Placebo
Dried flower cigarette with both placebo tobacco and cannabis
Canadian Sites (1)
1 of 1 recruiting
- Recruiting
Centre for Addiction and Mental Health
Toronto, Ontario
Eligibility Criteria
See who this study is looking for27 criteria
The trial’s own eligibility text, word for word from the registry. Only the trial site can say who takes part.
Inclusion
- +• Adults aged 19 years to 45 years (to controlControl groupThe group a new treatment is measured against.Read more → for the effects of age on cognition)
- +G2 or full G driver's licence for at least a year
- +Willing to abstain from alcohol and other drugs (other than drugs required for treatment of a medical condition) for 48 hours prior to study session
- +Provides written and informed consentInformed consentThe process of being told what taking part involves, then choosing freely.Read more →
- +Willing to use an accepted form of contraception during the study (both males and females)
- +Smoke or vape cannabis at least once a month but no more than 4 times a week (to avoid enrolling people with cannabis use disorder who may experience withdrawal when asked to abstain from cannabis)
- +Experience with smoked cannabis in the past year
- +Report use of at least 100 cigarettes in their lifetime to ensure familiarity with the tobacco used in the present study
- +Use of any nicotine (smoked, vaped, etc) in the past year
- +Normal heart rate and blood pressure as determined by the QI (because cannabis and tobacco increase heart rate)
- +Normal ECG (because cannabis and tobacco increase heart rate)
- +Willing to abstain from cannabis for 72 hours prior to the test session and from smoking tobacco for 12 hours
- +Past lifetime experience with co-use of cannabis or tobacco (either simultaneous or concurrent)
Exclusion
- −• Use of psychoactive medications or drugs
- −Current alcohol or other substance use disorder, including cannabis (as assessed with the SCID)
- −Withdrawal symptoms as assessed with the Marijuana Withdrawal Checklist \[57, 58\]
- −A score of less than 10 on the Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar) \[59\]
- −Family history of schizophrenia or psychosis (to avoid giving cannabis to anyone with a predisposition to psychosis)
- −Any serious medical condition precluding participation as judged by the responsible study physician
- −Negative urine screen for cannabis at eligibilityEligibility criteriaThe full list of requirements for taking part in a study.Read more → assessment (to ensure experience with cannabis)
- −Neurological disorders that may affect cognitive function
- −Concomitant therapy with sedative-hypnotics or other psychoactive drugs (counter-indicated with cannabis)
- −Pregnancy or breastfeeding
- −Current or past nicotine dependence (to avoid precipitating a relapse)
- −Respiratory illnesses (due to the smoked route of administration in this study)
- −Treatment-seeking for tobacco or cannabis use
- −Use of more than 5 cigarettes a day (to avoid confound of the effects of chronic smoking on measures)
In plain language
Assembled directly from this trial’s registry record. Every sentence traces to a field below — nothing here is generated or interpreted.
What this study is
This study is investigating how something functions in the body, rather than testing a treatment directly.
This study is not organised into the usual phase numbers — that is common for device, behavioural, and diagnostic research.
From the trial registry
Built from these fields:
- designModule.designInfo.primaryPurpose
- designModule.phases
Who receives what
There are 4 groups in this study.
Group A receives PlaceboPlaceboA dummy treatment with no active medicine, used for comparison.Read more →.
Registry label: A: Placebo
Group B receives Tobacco.
Registry label: B: Tobacco
Group C receives Cannabis.
Registry label: C: Cannabis
Group D receives Cannabis tobacco.
Registry label: D: Tobacco and cannabis
From the trial registry
Built from these fields:
- armsInterventionsModule.armGroups[].label
- armsInterventionsModule.armGroups[].type
- armsInterventionsModule.armGroups[].interventionNames
How the study is run
Groups are assigned by the study team using set rules, rather than by chance.
Neither you nor the study team would know which group you are in until the study ends.
From the trial registry
Built from these fields:
- designModule.designInfo.allocation
- designModule.designInfo.maskingInfo.masking
Is there a placebo?
One group receives a placeboPlaceboA dummy treatment with no active medicine, used for comparison.Read more → — a dummy treatment with no active medicine in it — alongside the other treatment that group is given.
From the trial registry
Built from these fields:
- armsInterventionsModule.armGroups[].type
- armsInterventionsModule.armGroups[].interventionNames
Who the study is looking for
The study lists an age range of 19 years to 45 years.
The study is open to people of any sex.
The study accepts healthy volunteersHealthy volunteerSomeone without the condition being studied who takes part anyway.Read more → as well as people with the condition.
These are the criteria the study lists. Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can decide whether someone can take part.
From the trial registry
Built from these fields:
- eligibilityModule.minimumAge
- eligibilityModule.maximumAge
- eligibilityModule.sex
- eligibilityModule.healthyVolunteers
How big and how long
The study aims to enrol about 60 people.
The study is currently expected to finish around March 2027.
The main measurement is taken over: baselineBaselineYour starting measurements, taken before treatment begins.Read more →.
From the trial registry
Built from these fields:
- designModule.enrollmentInfo.count
- statusModule.completionDateStruct.date
- outcomesModule.primaryOutcomes[].timeFrame
What the study measures
Standard deviation of lateral position — measured over baselineBaselineYour starting measurements, taken before treatment begins.Read more →.
Standard deviation of lateral position — measured over 15 minutes post smoking.
Standard deviation of lateral position — measured over 180 minutes post smoking.
From the trial registry
Built from these fields:
- outcomesModule.primaryOutcomes[].measure
- outcomesModule.primaryOutcomes[].timeFrame
Source: NCT05526196 on ClinicalTrials.gov. The full registry text is further down this page — this summary never replaces it.
Not medical advice. What do these terms mean?
What is being tested — in plain terms
About CannabisDrug
Dried flower cannabis cigarette with 22% THC
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About TobaccoDrug
Dried flower cigarette with active nicotine
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About Cannabis tobaccoDrug
Dried flower cigarette with active nicotine and cannabis
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About PlaceboDrug
Dried flower cigarette with both placebo tobacco and cannabis
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
Common questions
Answered from this trial’s registry record. Where the record doesn’t say, these answers say so rather than filling the gap.
Am I eligible for this trial?
Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can decide whether someone can take part. Concord cannot make that determination, and neither can any tool that has not examined you.
What the study lists: an age range of 19 years to 45 years.
The full inclusionInclusion criteriaThe things you must have or be for a study to consider you.Read more → and exclusion criteriaExclusion criteriaThe things that would prevent someone from taking part.Read more → are published on this page, exactly as the study team wrote them.
The useful next step is to bring this trial to your doctor. Answering a few questions first gives them something concrete to review.
From the trial registry
- eligibilityModule.minimumAge
- eligibilityModule.maximumAge
- eligibilityModule.eligibilityCriteria
Is there a placebo?
Yes. One group receives a placeboPlaceboA dummy treatment with no active medicine, used for comparison.Read more → — a dummy treatment with no active medicine in it — alongside the other treatment that group is given.
From the trial registry
- armsInterventionsModule.armGroups[].type
Would I know which treatment I am getting?
Neither you nor the study team would know which group you are in until the study ends.
Groups are assigned by the study team using set rules, rather than by chance.
From the trial registry
- designModule.designInfo.maskingInfo.masking
- designModule.designInfo.allocation
Who can join?
The study lists an age range of 19 years to 45 years.
It is open to people of any sex.
It accepts healthy volunteersHealthy volunteerSomeone without the condition being studied who takes part anyway.Read more → as well as people with the condition.
Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can confirm whether a particular person can take part.
From the trial registry
- eligibilityModule.minimumAge
- eligibilityModule.maximumAge
- eligibilityModule.sex
- eligibilityModule.healthyVolunteers
How long would this take?
The study's main measurement is taken over: baselineBaselineYour starting measurements, taken before treatment begins.Read more →.
The study as a whole is currently expected to finish around 2027-03-01.
How long any one person takes part can differ from the study length. The study team can tell you what the schedule looks like in practice.
From the trial registry
- outcomesModule.primaryOutcomes[].timeFrame
- statusModule.completionDateStruct.date
How many people are taking part?
The study aims to enrol about 60 people.
From the trial registry
- designModule.enrollmentInfo.count
Where is this happening?
This study lists one location: Toronto, Ontario, Canada.
Sites can open and close during a study, so confirm with the team before travelling.
From the trial registry
- trial_locations
About This Trial
Co-administration of cannabis and tobacco is a common practice, but there is little experimental evidence aimed at understanding the reasons for this prevalence. Some preliminary evidence suggests that tobacco may actually counteract the cognitive-impairing effects of cannabis, and may also increase the subjective ('liking') effects of cannabis, but results are inconclusive. Further, there are no studies into the effects of tobacco on other cannabis-related harms such as driving, or on the ability of tobacco to alter the blood levels of THC, the chemical responsible for the psychoactive properties of cannabis. The purpose of the present study will be to evaluate the effects of tobacco, cannabis or combinations of tobacco and cannabis on driving, cognition, subjective effects and blood THC. Driving will be assessed using a state-of-the-art driving simulator that allows for the safe and objective measurement of the effects of intoxicating substances on driving. Participants will be regular users of cannabis and will be invited to the lab for four counterbalanced test sessions. In these test sessions they will drive the simulator and undergo cognitive tests before and after smoking: 1) cannabis; 2) tobacco; 3) cannabis + tobacco; or 4) placebo. Outcomes will be measured at several time points after smoking the product. Participants will also give blood for determination of levels of THC, and will complete subjective effects questionnaires both before and after smoking the cigarette. This study will be one of the first experimental laboratory studies of the reasons behind co-administration of tobacco and cannabis.
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See if this trial could fit youThis page is for informational purposes only and does not constitute medical advice. Clinical trial eligibility can only be determined by the trial site after proper screening. Trial information is sourced from ClinicalTrials.gov and may not reflect the most current status. Always consult your healthcare provider before making decisions about clinical trial participation.