Electrophysiological Study of the Functioning of Magnocellular Visual Pathway in Regular Cannabis Users

Cannabis Use Clinical Trial

— CAUSA MAP  

Official title:

Electrophysiological Study of the Functioning of Magnocellular Visual Pathway in Regular Cannabis Users

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02864680
• Other study ID #: 2013-A00097-38
• Status: Completed
• Phase: N/A
• Start date: February 2014
• Est. completion date: June 2019

Study information

• Verified date: June 2019
• Source: Central Hospital, Nancy, France
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This study will evaluate the impact of regular use of cannabis on the spatial sensitivity of magnocellular system (visual event-related potential, visual ERP).

Secondary purposes of this study are to evaluate the impact of regular use of cannabis on the temporal sensitivity of magnocellular system (visual event-related potential), on the dynamics of cortical visual processing during face perception test (visual event-related potential) and on functioning of retinal photopic and scotopic systems (electroretinogram).

The ancillary study is a genetic analysis of a group of candidate genes that aims to identify biomarkers for changes in visual processing. This will allow to distinguish among more homogeneous and specific groups in future studies on larger cannabis user population. This ancillary study concerns all participants subject to their informed consent (facultative study).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 163
• Est. completion date: June 2019
• Est. primary completion date: June 2019
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 55 Years

Eligibility

Inclusion Criteria:

• Affiliation to social security plan

• Normal visual acuity or adjusted to normal and normal dilated fundus examination

• Signature of informed consent

• Cannabis user group: More than 7 cannabis uses per week during the previous month

• Cannabis user group: Positive urinary analysis for presence of cannabis

• Healthy, non user control group: Absence of cannabis and tobacco use during last 12 months

• Healthy, non user control group: Negative urinary analysis for presence of cannabis

• Healthy, non user control group: Age and sex matching with cannabis user group

• Healthy, tobacco user control group: Tobacco use from at least 12 months

• Healthy, tobacco user control group: Low to very strong addiction to tobacco (Fagerström test)

• Healthy, tobacco user control group: Absence of cannabis use from more than 12 months

• Healthy, tobacco user control group: Negative urinary analysis for presence of cannabis

• Healthy, tobacco user control group:Age and sex matching with cannabis user group

• Schizophrenia patient control group: Schizophrenia according to DMS IV criteria (MINI test)

• Schizophrenia patient control group: Absence of cannabis use from more than one month (regardless of tobacco use)

• Schizophrenia patient control group: Negative urinary analysis for presence of cannabis

• Schizophrenia patient control group: Age and sex matching with cannabis user group

Exclusion Criteria:

• Acute psychiatric pathology (axis I of DSM IV, measured by MINI) except anxiety disorder (except schizophrenia group)

• Deficiency of the subject making difficult or impossible his/her participation to the study or the comprehension of the information

• Dyslexia

• Addiction to alcohol according to AUDIT scale

• Abuse or addiction to other substances according to DSM IV criteria

• Acute retinal disorder

• Chronic glaucoma

• Ophthalmic pathology affecting visual acuity

• Current ocular infection

• Persons under guardianship, curatorship or judicial protection

• Pregnant or breast-feeding women

• Persons with life-and-death emergency

• Absence of social security plan

• Results of preliminary medical examinations incompatible with the study

• Simultaneous participation to another therapeutic interventional study

Related Conditions & MeSH terms

• Cannabis Use
• Marijuana Abuse

Intervention

Other:
• Electroretinography

• Contrast sensitivity test during Electroencephalography
Stimuli are black and white grids, having different range of spatial frequencies, presented with different contrasts on a grey background thanks to a computer monitor, in a dark room. Participants are requested to maintain central fixation. During the test patients stay sit, head hold by chin strap. A pause can be asked by participant and done at every moment. This test lasts approximately 30 minutes.
• Visual simultaneity test during Electroencephalography
Two vertical bars are showed on a monitor, on the link and right of point of central fixation. Bars appear simultaneously or with a 10 to 200 ms asynchrony. Participants must determine whether stimuli are simultaneous or asynchronous and answer pressing the link button for simultaneity or right button for asynchrony. During the test patients stay sit, head hold by chin strap. A pause can be asked by participant and done at every moment. This test lasts approximately 30 minutes.
• Face perception test during Electroencephalography
Faces filtered in different spatial frequence ranges are showed randomly on a monitor, in a dark room. Participants must maintain a central fixation thank to a fixation cross. During the test patients stay sit, head hold by chin strap. A pause can be asked by participant and done at every moment. This test lasts approximately 30 minutes.
• CAST (cannabis abuse screening test)

• PANSS (Positive And Negative Symptoms Scale) test

• Delayed Matching to Sample (DMS) test

• Spatial Working Memory (SWM) test

• Rapid Visual Information Processing (RVP) test

• Test for attentional performance (TAP) / Divided Attention

• Collection of saliva sample
In case of specific consent of participant to ancillary study, for ancillary study

Locations

Country	Name	City	State
France	Maison des Addictions - CHU de Nancy, Hôpital St Julien	Nancy

Sponsors (1)

Lead Sponsor	Collaborator
Central Hospital, Nancy, France

Country where clinical trial is conducted

France, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Relationship between variants of candidate genes for alterations of visual treatment and amplitude of P100 wave in contrast sensibility test		up to 3 years
Primary	Amplitude of P100 wave in contrast sensibility test		up to 1 month
Primary	Culmination time of the P100 wave in contrast sensibility test		up to 1 month
Secondary	Amplitude of P100 wave in visual simultaneity test		up to 1 month
Secondary	Culmination time of P100 wave in visual simultaneity test		up to 1 month
Secondary	Amplitude of P100 wave in face perception test		up to 1 month
Secondary	Amplitude of N170 wave in face perception test		up to 1 month
Secondary	Culmination time of P100 wave in face perception test		up to 1 month
Secondary	Culmination time of N170 wave in face perception test		up to 1 month
Secondary	Amplitude of "a" wave in different ERG sequences		day 0
Secondary	Amplitude of "b" wave in different ERG sequences		day 0
Secondary	Culmination time of "a" wave in different ERG sequences		day 0
Secondary	Culmination time of "b" wave in different ERG sequences		day 0