Completed

Effects of Chronic Cannabis Use on Contrast Sensitivity in Driving

0 criteria met from your profileSee at a glance how your profile meets each eligibility criteria.
Study Aim

This study aims to compare the contrast detection threshold in driving among three groups: chronic cannabis users, occasional users, and non-users.

What is being tested

electroretinogram

+ contrast sensitivity tests

+ electroretinogram

Other
Who is being recruted

Mental Disorders+1

+ Substance-Related Disorders

+ Chemically-Induced Disorders

From 18 to 50 Years
+16 Eligibility Criteria
See all eligibility criteria
How is the trial designed

Other Study

Interventional
Study Start: March 2013
See protocol details

Summary

Principal SponsorUniversity Hospital, Strasbourg, France
Last updated: June 8, 2026
Sourced from a government-validated database.Claim as a partner

Study start date: March 22, 2013

Actual date on which the first participant was enrolled.

With the rise in driving under cannabis influence and its involvement in a third of motor vehicle collisions, this study focuses on understanding the effects of chronic cannabis use on contrast sensitivity. Contrast sensitivity is the ability to distinguish between an object and its background, which is crucial for safe driving. The study targets individuals who are addicted to cannabis, as chronic use may impair this ability due to changes in dopamine regulation. By comparing the results with standard references, the study aims to highlight potential risks associated with cannabis use and improve road safety. The study involves 36 cannabis addicts, 36 tobacco addicts, and 36 non-smokers. Participants will view gratings with varying spatial frequencies, and the study will determine their contrast thresholds for both static and moving gratings. The primary outcome is the comparison of contrast detection thresholds among the three groups. Researchers predict that cannabis addicts may show abnormal contrast sensitivity, particularly when the gratings are in motion.

NCT01793961
Principal SponsorUniversity Hospital, Strasbourg, France
Last updated: June 8, 2026
Sourced from a government-validated database.Claim as a partner

Protocol

This section provides details of the study plan, including how the study is designed and what the study is measuring.
Design Details

95 patients to be enrolled

Total number of participants that the clinical trial aims to recruit.

Other Study

Some studies explore topics that don't fall into a specific category. These might include innovative research, new technologies, or emerging healthcare areas.



Eligibility

Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.
Conditions
Criteria

Any sex

Biological sex of participants that are eligible to enroll.

From 18 to 50 Years

Range of ages for which participants are eligible to join.

Healthy volunteers allowed

If individuals who are healthy and do not have the condition being studied can participate.

Conditions

Pathology

Mental DisordersSubstance-Related DisordersChemically-Induced DisordersMarijuana Abuse

Criteria

8 inclusion criteria required to participate
Positive CAST test result

Urine tested positive for cannabis metabolites

patient addicted to cannabis

No history of addictive disorders

Show More Criteria

8 exclusion criteria prevent from participating
Adults under supervision or guardianship

Pregnant woman

addiction to other substances than cannabis or tobacco

benzodiazepine treatment

Show More Criteria

Study Plan

Find out more about all the medication administered in this study, their detailed description and what they involve.
Treatment Groups
Study Objectives

3 intervention groups are designated in this study

This study does not include a placebo group 

Treatment Groups

Group I

patient addicted to cannabis

Group II

patient addicted to tobacco

Group III

no smokers

Study Objectives

Primary Objectives

Study Centers

These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.

This study has 1 location

Strasbourg, FranceOpen in Google Maps
CompletedOne Study Center