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Effects of Chronic Intake of Cannabis on Contrast Sensitivity

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified February 2013 by University Hospital, Strasbourg, France.
Recruitment status was:  Not yet recruiting
Sponsor:
ClinicalTrials.gov Identifier:
NCT01793961
First Posted: February 18, 2013
Last Update Posted: February 18, 2013
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by (Responsible Party):
University Hospital, Strasbourg, France
  Purpose

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.


Condition Intervention
Chronic Intake of Cannabis. Other: electroretinogram Other: contrast sensitivity tests

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Official Title: Effects of Chronic Intake of Cannabis on Contrast Sensitivity

Resource links provided by NLM:

MedlinePlus related topics: Allergy Marijuana
U.S. FDA Resources

Further study details as provided by University Hospital, Strasbourg, France:

Primary Outcome Measures:
  • The contrast detection treshold [ Time Frame: up to 9 days after inclusion ]
    Comparison of the contrast detection threshold of the 3 groups
Estimated Enrollment: 108
Study Start Date: February 2013
Estimated Primary Completion Date: July 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
"Cannabis" Arm
patient addicted to cannabis
 Other: electroretinogram Other: contrast sensitivity tests
"Tobacco" Arm
patient addicted to tobacco
 Other: electroretinogram Other: contrast sensitivity tests
"Healthy volunteers"
no smokers
 Other: electroretinogram Other: contrast sensitivity tests

  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

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
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01793961


Contacts
Contact: Laurence Lalanne-Tongio, MD Laurence.lalanne@chru-strasbourg.fr

Sponsors and Collaborators
University Hospital, Strasbourg, France
  More Information

Responsible Party: University Hospital, Strasbourg, France
ClinicalTrials.gov Identifier: NCT01793961     History of Changes
Other Study ID Numbers: 5331
2012-A00991-42 ( Other Identifier: n° IDRCB )
First Submitted: February 12, 2013
First Posted: February 18, 2013
Last Update Posted: February 18, 2013
Last Verified: February 2013

Additional relevant MeSH terms:
Marijuana Abuse
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders