Neuroscience of Alcohol and Marijuana Impaired Driving
1 other identifier
observational
13
1 country
1
Brief Summary
Alcohol is one of the most widely used intoxicants. The effects of driving while intoxicated are well documented, leading to the laws and regulations behind drunk driving. Marijuana is also a commonly abused drug, whose use is increasing with widespread legalization/decriminalization in many US states and use of medical marijuana. Marijuana use is linked to cognitive impairment and is likely be the cause of intoxication-induced accidents. The effects of marijuana intoxication on driving impairments are less documented than those of alcohol. However, most marijuana users also consume alcohol when smoking cannabis, and preliminary data strongly suggest that driving impairment from both drugs used together is synergistic rather than just additive. This study will aim to investigate the brain and behavior in the same individuals, using a similar design to the current Neuroscience of Marijuana Impaired Driving and the prior Alcohol and Driving Grant, that used similar techniques and measures to quantify drunk automobile driving. We hypothesize that alcohol and marijuana use combined will lead to greater impairment in a simulated driving task, as well as other driving-related cognitive impairments. In a randomized, counterbalanced, double-blind study, we will dose participants with alcohol to a legal level of 0.05% blood alcohol content, then we will administer a moderate inhaled dose of THC marijuana or placebo marijuana, using paced inhalation that employees a vaporizer. Participants will comprise 10 regular alcohol and marijuana consumers aged 21 to 40 years of age; all participants must report smoking marijuana and drinking alcohol together. Of the 10, 5 will be occasional marijuana smokers and 5 frequent marijuana smokers. Following this dosing, we will assess impairment through cognitive testing as well as a simulated driving test through fMRI and neuropsychological tests. Samples of breath, blood and oral fluid will also be collected at multiple time points throughout the study visits to be measured for alcohol and THC concentration and its metabolites. This allows clarification between the relationship of impairment, as well as subjective and objective intoxication, and levels of THC and its metabolites in the users system.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for all trials
Started Jul 2018
Longer than P75 for all trials
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
February 7, 2018
CompletedFirst Posted
Study publicly available on registry
February 13, 2018
CompletedStudy Start
First participant enrolled
July 1, 2018
CompletedPrimary Completion
Last participant's last visit for primary outcome
December 1, 2023
CompletedStudy Completion
Last participant's last visit for all outcomes
December 1, 2023
CompletedAugust 5, 2022
August 1, 2022
5.4 years
February 7, 2018
August 4, 2022
Conditions
Keywords
Outcome Measures
Primary Outcomes (10)
Change in performance on simulated driving Gap Acceptance Task.
The Gap Acceptance Task measures strategic control of the vehicle. Strategic control of the vehicle is measured by size of headway gaps that the participant chooses in pulling out into a stream of traffic.
Post Dose: 30 minutes, 2.5 hours, and 5 hours
Change in performance on simulated driving Road Tracking Task.
The Road Tracking Task measures operational control of the vehicle. Operational control is measured by standard deviation of lane position from the center point of the lane.
Post Dose: 30 minutes, 2.5 hours, and 5 hours
Change in performance on simulated driving Car Following Task.
The Car Following Task measures tactical control of the vehicle. Tactical control of the vehicle is measured by following distance from a lead vehicle.
Post Dose: 30 minutes, 2.5 hours, and 5 hours
Change in concentration of THC/metabolites in oral fluid tested using Quantisal Oral Fluid Collection devices.
Saliva samples will be taken at 3 time points during the day using the Quantisal Oral Fluid Collection devices to assess for changes in concentration of THC and its metabolites.
Before Dose and Post Dose: 30 minutes and 2.5 hours
Change in concentration of THC/metabolites in blood samples.
Blood samples will be taken at 3 time points during the day to assess for changes in concentration of THC and its metabolites.
Before Dose and Post Dose: 30 minutes and 2.5 hours
Marijuana performance changes on the Critical Tracking Task.
The Critical Tracking Task assesses visuomotor tracking, it will be administered prior to dosing and at various time points after dosing
Post Dose: 2 hours, 4 hours and 6 hours
Intoxication induced performance changes on the Tower of London task.
The Tower of London is a task that assesses executive functioning, it will be administered prior to dosing and at various time points after dosing.
Post Dose: 2 hours, 4 hours and 6 hours
Intoxication induced performance changes on the Cogstate 1-back/2-back task.
The Cogstate 1-back/2-back task assesses working memory, it will be administered prior to dosing and at various time points after dosing.
Post Dose: 2 hours, 4 hours and 6 hours
Intoxication induced performance changes on the Cogstate Detection Task.
The Cogstate Detection Task assesses processing speed, it will be administered prior to dosing and at various time points after dosing.
Post Dose: 2 hours, 4 hours and 6 hours
Intoxication induced performance changes on the Cogstate Set Shifting Task.
The Cogstate Set Shifting Task assesses executive functioning, it will be administered prior to dosing and at various time points after dosing.
Post Dose: 2 hours, 4 hours and 6 hours
Secondary Outcomes (3)
Change in magnetic resonance spectroscopy scanning.
Post Dose: 2.5 hours
Change in electroencephalography at rest.
Post Dose: 10 minutes, 1.5 hours, 2.25 hours, 4.5 hours
Change in electroencephalography while completing the driving simulation.
Post Dose: 5 hours
Study Arms (1)
Marijuana Users
Interventions
Vaporized placebo marijuana with little to no THC paired with drinking alcohol to BrAC of 0.05%
Vaporized marijuana with active THC paired with drinking alcohol to BrAC of 0.05%
Eligibility Criteria
All participants that meet the study criteria sampled from the general population
You may qualify if:
- Must have a current drivers license
- Must have used marijuana and alcohol in combination before
- Right handed
You may not qualify if:
- Females who are pregnant or breastfeeding
- Unable or unsafe to have an MRI
- Any serious medical or neurological disorder
- Any psychiatric disorder
- No major head traumas
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
Olin Neuropsychiatry Research Center, Institute of Living, Hartford Hospital
Hartford, Connecticut, 06108, United States
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- observational
- Observational Model
- OTHER
- Time Perspective
- OTHER
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
February 7, 2018
First Posted
February 13, 2018
Study Start
July 1, 2018
Primary Completion
December 1, 2023
Study Completion
December 1, 2023
Last Updated
August 5, 2022
Record last verified: 2022-08