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:

Information provided by (Responsible Party):

University Hospital, Strasbourg, France

ClinicalTrials.gov Identifier:

NCT01793961

First received: February 12, 2013

Last updated: February 15, 2013

Last verified: February 2013

History of Changes

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: 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


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

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Please refer to this study by its ClinicalTrials.gov identifier: 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 )
Study First Received:	February 12, 2013
Last Updated:	February 15, 2013

Additional relevant MeSH terms:


Marijuana Abuse Substance-Related Disorders Chemically-Induced Disorders Mental Disorders

ClinicalTrials.gov processed this record on June 23, 2017

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