Cannabis Consumption for Driving Impairment

Overseen By Dario L Sacchi, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Phase 2

Sponsor: Bayliss J. Camp, PhD

Disqualifiers: Pregnancy, DUI, Parole, others

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: 2

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to understand how cannabis affects driving ability. Participants will smoke either active cannabis (containing THC, the psychoactive component), a placebo (cannabis without THC), or nothing at all, and then complete a driving test. California Highway Patrol officers will observe and assess driver impairment. Ideal candidates for this trial have used cannabis in the past six months, hold a valid California driver's license, and live within 15 miles of the study site. As a Phase 2 trial, this research measures how well cannabis affects driving in an initial, smaller group, offering participants a chance to contribute to important safety findings.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. However, you must abstain from alcohol, cannabis, and other recreational drugs for 24 hours before participating.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research shows that cannabis is usually well-tolerated. Studies have found that most people can use cannabis without serious side effects. Common side effects include dry mouth, dizziness, and a faster heartbeat. One study found these effects were temporary and mild for most users. Another report indicated that drivers with THC (the main active ingredient in cannabis) in their system do not have a significantly higher risk of serious accidents compared to those without it. This suggests that while cannabis can affect driving skills, it might not greatly increase the risk of crashes. However, it's important to remember that reactions can vary among individuals. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about this trial because it explores how cannabis consumption impacts driving ability, a topic with significant safety implications. Unlike traditional methods that rely on blood alcohol content to assess impairment, this study specifically examines the effects of THC, the active ingredient in cannabis, on driving. The trial includes an active smoked cannabis group and a placebo group, allowing for a direct comparison of real versus perceived effects. By pinpointing how THC levels correlate with driving skills, this study could lead to better guidelines and policies for cannabis use and driving safety.

What evidence suggests that this trial's treatments could be effective for driving impairment?

This trial will compare the effects of active smoked cannabis and placebo smoked cannabis on driving impairment. Research has shown that smoking cannabis can impair safe driving. For example, drivers might attempt to drive more slowly after using cannabis, yet their vehicle control can still deteriorate. One study found that smoking cannabis with 12.5% THC caused young adults to drive slower, but its impact on steering remained unclear. THC levels in the blood do not reliably predict driving ability. Overall, cannabis use can potentially impair essential driving skills. ^{2 6 7 8 9}

Who Is on the Research Team?

Bayliss J Camp, PhD

Principal Investigator

California Department of Motor Vehicles

Are You a Good Fit for This Trial?

This trial is for adults who've used cannabis in the last six months, have a valid California driver's license, and live close to the study site. They must not use alcohol or drugs for 24 hours before participating and can't drive afterwards for four hours. People with recent DUIs, on parole/probation, or with certain health conditions are excluded.

Inclusion Criteria

You have consumed cannabis in the past six months.

You are committed to refraining from alcohol, cannabis and other intoxicants for a 24 hour period before participating.

You possess a valid driver's license issued by the state of California.

Exclusion Criteria

I am not willing to travel by taxi.

Parole or probation status

Completion of a roadside sobriety test during the previous 12 months

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Intervention

Participants receive either active cannabis, placebo cannabis, or no substance at all

1 day

1 visit (in-person)

Assessment

Participants undergo driving tests and evaluations by CHP officers, including ARIDE and DRE evaluations

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after intervention

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Active smoked cannabis
• Placebo smoked cannabis

Trial Overview

The study tests how smoking actual cannabis versus a placebo affects driving ability. About 300 participants will be observed by police officers after completing a closed-course driving test to determine if they appear impaired using various roadside assessments.

How Is the Trial Designed?

Group I: Active Smoked Cannabis Experimental Treatment 1 Intervention

Participants in this arm will smoke an active cannabis cigarette containing 18.16% Δ9-tetrahydrocannabinol (THC). The smoking will occur at each participant's preferred pace, but will be limited to a maximum ten-minute period. While individual doses vary in this type of paradigm (ad libitum dosing), the anticipated dose of THC within the cannabis condition can be approximated by the following formula: (700 mg of cannabis) x \[% of cigarette smoked; maximum of 70% (allowing room to hold the cigarette)\] x (% THC). Therefore, the maximum dose in this arm is 700 mg x 70% x 18.2% = 89.18 mg of THC. Individual participants will only take part in the study under a single condition and receive the active cannabis once. Bulk cannabis for this arm will be provided by the National Institute on Drug Abuse Drug Supply Program; cannabis cigarettes will be prepared and prescribed by the Research Pharmacy of the University of California, San Diego.

Group II: Control Active Control 1 Intervention

Participants in this arm receive no cannabis. Individual participants will only take part in the study under a single condition.

Group III: Placebo Smoked Cannabis Placebo Group 1 Intervention

Participants in this arm will smoke a placebo cannabis cigarette containing \<.01 THC. The smoking will occur at each participant's preferred pace, but will be limited to a maximum ten-minute period. Individual participants will only take part in the study under a single condition and receive the placebo cannabis once. Bulk placebo for this arm will be provided by the National Institute on Drug Abuse Drug Supply Program; placebo cannabis cigarettes will be prepared and prescribed by the Research Pharmacy of the University of California, San Diego.

Who Is Running the Clinical Trial?

Bayliss J. Camp, PhD

Lead Sponsor

Trials

1

Recruited

300+

Citations

1.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC3836260/

Cannabis Effects on Driving Skills - PMC - PubMed Central

Experimental data show that drivers attempt to compensate by driving more slowly after smoking cannabis, but control deteriorates with increasing task ...

2.

clinicaltrials.gov

clinicaltrials.gov/study/NCT06059677

Cannabis Consumption and Driving Impairment ...

In a true experiment, roughly 300 volunteer participants will smoke active cannabis, a corresponding placebo, or no substance at all (control).

3.

sciencedirect.com

sciencedirect.com/science/article/abs/pii/S0376871619304181

Acute and residual effects of smoked cannabis: Impact on ...

Smoked cannabis (12.5% THC) led to an acute decrease in speed in young adults. · There was no clear effect of smoked cannabis on lateral control.

4.

nhtsa.gov

nhtsa.gov/sites/nhtsa.gov/files/documents/812440-marijuana-impaired-driving-report-to-congress.pdf

Marijuana-Impaired Driving – A Report to Congress

Despite the variability in results, this research has demonstrated the potential of marijuana to impair driving related skills. It does not show a relationship ...

5.

jamanetwork.com

jamanetwork.com/journals/jamapsychiatry/fullarticle/2807719

Evaluation of Field Sobriety Tests for Identifying Drivers ...

Unlike the association of blood alcohol concentrations with impairment, THC blood concentrations do not correlate with driving performance, ...

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC8792796/

Driving Performance and Cannabis Users' Perception ...

This randomized clinical trial studies the magnitude and time course of effects of cannabis on driving, effect of cannabis with different tetrahydrocannabinol ...

7.

cdc.gov

cdc.gov/cannabis/health-effects/driving.html

Cannabis and Driving

12 Cannabis use can impair important skills required for safe driving by:12. slowing your reaction time and ability to make decisions ...

8.

nsc.org

nsc.org/getmedia/8840b317-9960-48b9-a3ae-3fec77a9448b/Position-on-Cannabis-and-Driving.pdf?srsltid=AfmBOookrOQRGZY1G-kFDbZpBe2O_FzjwzsKYSmOu7ZFez16Mf9_l46s

Position-on-Cannabis-and-Driving.pdf

POSITION / POLICY: Driving under the influence of cannabis1 is an important public safety concern. Drug impaired driving endangers those both inside and ...

9.

mpp.org

mpp.org/issues/criminal-justice/marijuana-and-dui-laws/

Marijuana and DUI Laws

The NHTSA's large, case-controlled study found that drivers who tested positive for THC had identical crash risk as those testing negative for cannabis once ...