Effects of Chronic Intake of Cannabis on Contrast Sensitivity (NCT01793961) | Clinical Trial Compass
CompletedNot Applicable
Effects of Chronic Intake of Cannabis on Contrast Sensitivity
France95 participantsStarted 2013-03-22
Plain-language summary
Rates of driving under the influence of cannabis have risen in recent years. Cannabis is involved in 1/3 of motor vehicle collisions. The chronic use of cannabis is known to affect dopaminergic regulation and may thus impair contrast sensitivity. In turn, contrast sensitivity disorders could originate difficulties to anticipate and avoid collision with objects, especially when objects are in movement. The investigators goal is to examine the effects of a chronic intake of cannabis on contrast sensitivity. The observed values will be compared to standard references. In addition, since smoking cannabis is always associated with tobacco, the investigators will control the effects of tobacco on contrast sensitivity.
In this study, the investigators will include 36 cannabis addicts, 36 tobacco addicts and 36 no smokers. The investigators will present gratings with different spatial frequencies and the investigators will determine contrast thresholds for static and dynamic (moving) gratings. The investigators predict that cannabis addicts will present abnormal contrast sensitivity especially in case of dynamic presentation of gradings.
Who can participate
Age range
18 Years – 50 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
"Cannabis" Arm
* patient addicted to cannabis
* Positive CAST test result
* Urine tested positive for cannabis metabolites
"Tobacco" Arm
* positive Fagerström test result
* No cannabis intake in the last year before inclusion
* No previous history of cannabis use
"Healthy Volunteers"
* No tobacco or cannabis intake in the last year before inclusion
* No history of addictive disorders
Exclusion Criteria:
* addiction to other substances than cannabis or tobacco
* benzodiazepine treatment
* patient with history of benzodiazepine treatment
* patient with history of general anesthesia in the last 3 months before inclusion
* patient with history of head trauma
* Pregnant woman
* breast feeding woman
* Adults under supervision or guardianship
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.