Effect of Cannabidiol (CBD) on Vision and Driving

Cannabis Use Clinical Trial

Official title:

Effect of Cannabidiol (CBD) Consumption on Visual Function and Driving Performance

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT06322303
• Other study ID #: C-EXP-194-UGR23
• Status: Active, not recruiting
• Phase: Early Phase 1
• Start date: February 1, 2023
• Est. completion date: December 31, 2025

Study information

• Verified date: March 2024
• Source: Universidad de Granada
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The use of cannabis with ∆9-tetrahydrocannabinol (THC) content has been shown to have negative effects on vision and driving. The use of other cannabinoids, such as cannabidiol (CBD), which is not attributed with a psychoactive effect, is increasing significantly. This project aims to investigate whether consuming CBD can negatively affect visual function by assessing a wide range of visual parameters and whether these changes may pose a risk for everyday activities such as driving.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 60
• Est. completion date: December 31, 2025
• Est. primary completion date: September 30, 2023
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 43 Years

Eligibility

Inclusion Criteria:

• Being an occasional cannabis and/or cannabidiol user
• Have a current driving licence
• Have at least one year's driving experience
• Drive at least once a week
• Monocular visual acuity of at least 6/6 (Snellen) with habitual correction for driving
• Absence of binocular disorders

Exclusion criteria:

• Certain past or present medical conditions
• Current cannabis or alcohol use disorder
• Use of other drugs
• Pregnancy or lactation
• Simulator sickness.

Related Conditions & MeSH terms

• Cannabis Use
• Marijuana Abuse

Intervention

Other:
• Placebo (CBD 0%)
Participants are required to vaporize placebo at 0% CBD concentration
• CBD 15%
Participants are required to vaporize CBD at a concentration of 15%.
• CBD 30%
Participants are required to vaporize CBD at a concentration of 30%.

Locations

Country	Name	City	State
Spain	University of Granada	Granada

Sponsors (1)

Lead Sponsor	Collaborator
Universidad de Granada

Country where clinical trial is conducted

Spain, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in Overall Driving Performance Score (ODPS) after cannabidiol vaporization	To obtain the ODPS, Z-scores were calculated from individual parameters such as the standard deviation of the lateral lane position or the distance travelled into the opposite lane. The z-score is defined as a measure of how many standard deviations an individual value is below or above the group mean. The average Z-score of the individual driving variables is called the ODPS.	Participants are assessed 20 minutes after vaporization
Primary	Change in motion detection sensitivity after cannabidiol vaporization	The subject has to indicate the direction of movement of a pattern of moving dots. The percentage of correct answers is obtained for different degrees of coherence.	Participants are assessed 20 minutes after vaporization
Primary	Change in contrast sensitivity after cannabidiol vaporization	Contrast thresholds are obtained for different spatial frequencies	Participants are assessed 20 minutes after vaporization
Primary	Change in visual acuity after cannabidiol vaporization	Visual acuity is assessed with a commercial test for distance vision.	Participants are assessed 20 minutes after vaporization
Primary	Change in fixations after cannabidiol vaporization	The number of fixations made on different stimuli of interest in a task environment is counted using an eye tracker system.	Participants are assessed 20 minutes after vaporization
Secondary	Driving simulator: standard deviation of the lateral lane position (SDLP)		Participants are assessed 20 minutes after vaporization
Secondary	Distance travelled outside the lane	The SDLP assesses the lane weaving that the subject performs in the lane and indicates whether the vehicle's position is consistent.	Participants are assessed 20 minutes after vaporization
Secondary	Mean speed	Average speed is obtained and analyzed in relation to the speed limits for different sections.	Participants are assessed 20 minutes after vaporization
Secondary	Angular velocity of the steering wheel	The angular velocity of the steering wheel is a metric that indicates the subject's ability to maintain the vehicle's position.	Participants are assessed 20 minutes after vaporization