alcohol
A single oral administration of an alcoholic beverage mixed in a 1:3 ratio of alcohol to tonic water to obtain a target blood alcohol content of 0.08mg%.
ethanolLoading study record…
Alcohol and cannabis are the two most widely used substances of abuse in the world and are the psychoactive substances most often found in seriously and fatally injured drivers. In a recent study, it was observed that individuals who reported both driving under the influence of alcohol (DUIA) and the influence of cannabis (DUIC) experienced collision risk that was nearly 4 times that of individuals who reported driving after using only one of these drugs. Recent research in the United States and Canada indicates that the prevalence of DUIC among young drivers of high school and university age, and young adults is similar to, or higher than, the prevalence of DUIA. This is a serious public health issue, since motor vehicle collisions are the leading cause of death in this age group. Given the frequency with which alcohol and cannabis are consumed together, it is important to understand their combined effects on driver behaviour. The current study will examine the acute effects of a moderate dose of cannabis (12.5% THC) combined with an intoxicating amount of alcohol (BAC=0.08) on driving simulator performance of young drivers. Following an eligibility screening and practice session, a total of 70 participants aged 19 to 29 years will each complete 4 experimental sessions. During each session, participants will drink alcohol or placebo alcohol and smoke an active or placebo cannabis cigarette. The effects of alcohol and cannabis on the performance of driving-related skills will be assessed using a high-fidelity driving simulator. Cognitive, psychomotor, and mood effects will also be assessed.
Locally preserved from ClinicalTrials.govOpen ClinicalTrials.govlast source update 2026-07-24
What this record can show
Results are reported by the registry submitter and preserved exactly. They are not independent verification or a treatment recommendation.
Registry facts
The proposed study will pursue the following primary aims: Aim 1: Examine the acute effects of a moderate dose of cannabis (12.5% THC) combined with an intoxicating amount of alcohol (BAC=0.08) on driving simulator performance of young drivers. Simulated driving performance, tests of cognition, verbal memory, and mood will be measured concurrently with BAC and levels of cannabinoids in biological fluids before and after acute drug exposure in male and female drivers aged 19 to 29. BAC and biological fluids will be measured up to 5 hours following drug exposure. Aim 2: Explore the effects of driving history, driving attitudes, and individual difference measures (e.g., demographics, drug and alcohol use, etc.) on the acute effects of alcohol and cannabis on driving simulator performance of young drivers. Exploratory analyses will be undertaken to determine if the acute effects of cannabis plus alcohol on the driving simulator task are influenced by these measures. Study Design and Duration This study will be a within-subjects, double-blind, double-dummy, placebo-controlled, counterbalanced, randomized clinical trial assessing the impact of alcohol and cannabis combined on driver behaviour. Although a placebo condition is part of the study, this is not a treatment study. Initial contact with potential participants 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. Participants will attend CAMH for a total of 6 study sessions (an eligibility assessment, a practice day, and 4 test sessions). At each of four test sessions, participants will undergo one of these alcohol and cannabis exposure conditions: 1) placebo alcohol and placebo cannabis; 2) intoxicating dose of alcohol and placebo cannabis; 3) placebo alcohol and active cannabis, and; 4) intoxicating dose of alcohol and active cannabis. The order of these conditions will be randomly assigned. Participants will complete the alcohol manipulation followed by the cannabis manipulation. The alcohol and cannabis exposure sessions will be separated by at least 72 hours. Participants will be asked not to use cannabis for 72 hours and alcohol for 48 hours prior to attending CAMH. 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.
Linked local records
Local links use governed condition terms or exact source-reported intervention names. They are navigation candidates, not efficacy claims.
Interventions
A single oral administration of an alcoholic beverage mixed in a 1:3 ratio of alcohol to tonic water to obtain a target blood alcohol content of 0.08mg%.
ethanolA single oral administration of a beverage containing tonic water of the same volume as the alcoholic beverage.
tonic waterA single cannabis cigarette (potency 12.5% delta 9 tetrahydrocannabinol) will be given to participants to smoke over a 10 minute period, ad libitum. If the cannabis cigarette is not smoked in its entirety, the remainder will be weighed to estimate dose.
marijuana · cannabis sativaA single placebo cannabis cigarette (\<0.03% delta 9 tetrahydrocannabinol) will be given to participants to smoke over a 10 minute period, ad libitum. If the placebo cannabis cigarette is not smoked in its entirety, the remainder will be weighed to estimate dose.
Source-reported results
Results are reported by the registry submitter and preserved exactly. They are not independent verification or a treatment recommendation.
The driving simulator objectively measures changes in driving behavior after alcohol and/or cannabis exposure. Standard deviation of lateral position (SDLP) is a measure of lane control (higher SDLP indicates worse lane control).
| Group | N | Value | Spread / interval |
|---|---|---|---|
| Participant Group | 28 | 0.30 | 0.01 |
| Participant Group | 28 | 0.32 | 0.01 |
| Participant Group | 28 | 0.33 | 0.01 |
| Participant Group | 28 | 0.28 | 0.01 |
| Participant Group | 28 | 0.28 | 0.01 |
| Participant Group | 28 | 0.33 | 0.01 |
| Participant Group | 28 | 0.32 | 0.02 |
| Participant Group | 28 | 0.38 | 0.02 |
The driving simulator will objectively measure changes in driving behavior after alcohol and/or cannabis exposure. Mean speed during the driving scenarios is measured by the simulator.
| Group | N | Value | Spread / interval |
|---|---|---|---|
| Participant Group | 28 | 84.07 | 0.84 |
| Participant Group | 28 | 85.06 | 1.38 |
| Participant Group | 28 | 83.27 | 0.78 |
| Participant Group | 28 | 84.64 | 1.82 |
| Participant Group | 28 | 83.23 | 0.94 |
| Participant Group | 28 | 87.34 | 2.10 |
| Participant Group | 28 | 83.45 | 1.09 |
| Participant Group | 28 | 85.25 | 2.27 |
The driving simulator will objectively measure changes in driving behavior after alcohol and/or cannabis exposure. The simulator also (in addition to mean speed) measures standard deviation of speed.
| Group | N | Value | Spread / interval |
|---|---|---|---|
| Participant Group | 28 | 4.72 | 0.55 |
| Participant Group | 28 | 5.80 | 0.78 |
| Participant Group | 28 | 4.37 | 0.47 |
| Participant Group | 28 | 4.81 | 0.44 |
| Participant Group | 28 | 4.92 | 0.29 |
| Participant Group | 28 | 6.38 | 0.59 |
| Participant Group | 28 | 5.15 | 0.36 |
| Participant Group | 28 | 6.06 | 0.39 |
The driving simulator will objectively measure changes in driving behavior after alcohol and/or cannabis exposure. The simulator measures maximum speed over the duration of the scenarios.
| Group | N | Value | Spread / interval |
|---|---|---|---|
| Participant Group | 28 | 93.85 | 3.01 |
| Participant Group | 28 | 98.85 | 3.02 |
| Participant Group | 28 | 94.64 | 1.65 |
| Participant Group | 28 | 97.76 | 2.41 |
| Participant Group | 28 | 95.84 | 1.43 |
| Participant Group | 28 | 102.84 | 2.91 |
| Participant Group | 28 | 97.04 | 1.73 |
| Participant Group | 28 | 101.08 | 2.68 |
The driving simulator objectively measures changes in driving behavior after alcohol and/or cannabis exposure. During specific reaction time scenarios, participants must stop as quickly as possible after certain visual cues. The brake latency variable is measured as the mean stop/reaction time in seconds after the visual cue is presented.
| Group | N | Value | Spread / interval |
|---|---|---|---|
| Participant Group | 28 | 0.99 | 0.03 |
| Participant Group | 28 | 1.04 | 0.02 |
| Participant Group | 28 | 0.99 | 0.03 |
| Participant Group | 28 | 1.04 | 0.02 |
Interim analyses allowed us to check if stopping the trial was warranted, because it is not justified to keep going if there is an effect with a smaller sample size. The analysis was conducted with n = 28 participants and SDLP was used as the primary measure. It was determined that stopping the study at a smaller sample size was warranted as we were powered to see an effect with 27 participants. The study continued until 30 participants had completed all study procedures.
| Milestone | Participant Group |
|---|---|
| STARTED | 49 |
| Received placebo alcohol/placebo cannabis | 38 |
| Received active alcohol/placebo cannabis | 40 |
| Received placebo alcohol/active cannabis | 41 |
| Received active alcohol/active cannabis | 40 |
| COMPLETED | 35 |
| NOT COMPLETED | 14 |
| Event | System | Groups: affected / at risk |
|---|---|---|
| Nausea/Vomiting | Gastrointestinal disorders | Active Alcohol/Active Cannabis: 3 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 5 / 40 · Placebo Alcohol/Placebo Cannabis: 2 / 38 |
| Decreased appetite | Metabolism and nutrition disorders | Active Alcohol/Active Cannabis: 1 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Pain/Bruising at site of blood draw | Skin and subcutaneous tissue disorders | Active Alcohol/Active Cannabis: 1 / 40 · Placebo Alcohol/Active Cannabis: 2 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 1 / 38 |
| Skin infection at site of blood draw | Skin and subcutaneous tissue disorders | Active Alcohol/Active Cannabis: 1 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Anxiety | Psychiatric disorders | Active Alcohol/Active Cannabis: 0 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Dizziness/Faintness | General disorders | Active Alcohol/Active Cannabis: 0 / 40 · Placebo Alcohol/Active Cannabis: 2 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Abormal vitals, pale skin | Cardiac disorders | Active Alcohol/Active Cannabis: 0 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Coughing | Respiratory, thoracic and mediastinal disorders | Active Alcohol/Active Cannabis: 0 / 40 · Placebo Alcohol/Active Cannabis: 1 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
Eligibility
primary outcomes
Time frame: Alcohol exposure is Time 0. Cannabis exposure follows 15 minutes after Time 0. Driving simulation tests occur within 2 hours before and approximately 45 minutes after Time 0.
The driving simulator objectively measures changes in driving behavior after alcohol and/or cannabis exposure. Standard deviation of lateral position (SDLP) is a measure of lane control (higher SDLP indicates worse lane control).
secondary outcomes
Time frame: Alcohol exposure is Time 0. Cannabis exposure follows 15 minutes after Time 0. Driving simulation tests occur within 2 hours before and approximately 45 minutes after Time 0.
The driving simulator will objectively measure changes in driving behavior after alcohol and/or cannabis exposure. Mean speed during the driving scenarios is measured by the simulator.
Time frame: Alcohol exposure is Time 0. Cannabis exposure follows 15 minutes after Time 0. Driving simulation tests occur within 2 hours before and approximately 45 minutes after Time 0.
The driving simulator will objectively measure changes in driving behavior after alcohol and/or cannabis exposure. The simulator also (in addition to mean speed) measures standard deviation of speed.
Time frame: Alcohol exposure is Time 0. Cannabis exposure follows 15 minutes after Time 0. Driving simulation tests occur within 2 hours before and approximately 45 minutes after Time 0.]
The driving simulator will objectively measure changes in driving behavior after alcohol and/or cannabis exposure. The simulator measures maximum speed over the duration of the scenarios.
Time frame: Alcohol exposure is Time 0. Cannabis exposure follows 15 minutes after Time 0. Driving simulation tests occur at baseline and approximately 45 minutes after Time 0.
The driving simulator objectively measures changes in driving behavior after alcohol and/or cannabis exposure. During specific reaction time scenarios, participants must stop as quickly as possible after certain visual cues. The brake latency variable is measured as the mean stop/reaction time in seconds after the visual cue is presented.
Publications
No exact PMID-linked public article is currently readable locally.
| Headache | General disorders | Active Alcohol/Active Cannabis: 2 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Memory effects | General disorders | Active Alcohol/Active Cannabis: 0 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Urinary tract infection | Renal and urinary disorders | Active Alcohol/Active Cannabis: 0 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 1 / 38 |
| Shingles infection | Skin and subcutaneous tissue disorders | Active Alcohol/Active Cannabis: 0 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 1 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Finger fracture | Injury, poisoning and procedural complications | Active Alcohol/Active Cannabis: 0 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 1 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Common cold symptoms | Infections and infestations | Active Alcohol/Active Cannabis: 3 / 40 · Placebo Alcohol/Active Cannabis: 1 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Menstrual cramps | Reproductive system and breast disorders | Active Alcohol/Active Cannabis: 1 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |
| Bloodshot eyes | Eye disorders | Active Alcohol/Active Cannabis: 1 / 40 · Placebo Alcohol/Active Cannabis: 0 / 41 · Active Alcohol/Placebo Cannabis: 0 / 40 · Placebo Alcohol/Placebo Cannabis: 0 / 38 |