Cannabis UseCAUSA MAPNCT02864680
Electrophysiological Study of the Functioning of Magnocellular Visual Pathway in Regular Cannabis Users
A study testing Electroretinography, Contrast sensitivity test during Electroencephalography and Visual simultaneity test during Electroencephalography in people with Cannabis Use, run by Central Hospital, Nancy, France at 1 site in France.
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… Read more about this study
- Who is it for?
- Ages 18 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Cannabis Use
- What is being tested?
- Electroretinography, Contrast sensitivity test during Electroencephalography and Visual simultaneity test during Electroencephalography
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 163 participants
- Where
- 1 siteFrance
- Study dates
- Feb 2014to Jun 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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
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- 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
Who cannot join
- 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
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- 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
Trial locations and contacts
1 site in 1 country.
About this study
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).
- Conditions
- Cannabis Use
- Being tested
- Electroretinography, Contrast sensitivity test during Electroencephalography, Visual simultaneity test during Electroencephalography, Face perception test during Electroencephalography, CAST (cannabis abuse screening test)
- Keywords
- cannabis, magnocellular pathway
- Medical subject headings
- Marijuana Abuse
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ElectroretinographyOther
Contrast sensitivity test during ElectroencephalographyOther
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 ElectroencephalographyOther
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 ElectroencephalographyOther
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)Other
PANSS (Positive And Negative Symptoms Scale) testOther
Delayed Matching to Sample (DMS) testOther
Spatial Working Memory (SWM) testOther
Rapid Visual Information Processing (RVP) testOther
Test for attentional performance (TAP) / Divided AttentionOther
Collection of saliva sampleOther
In case of specific consent of participant to ancillary study, for ancillary study
| Study group | Role | What they receive |
|---|---|---|
| Cannabis users | Other | Not described Receives: Other: Electroretinography; Other: Contrast sensitivity test during Electroencephalography; Other: Visual simultaneity test during Electroencephalography; Other: Face perception test during Electroencephalography; Other: CAST (cannabis abuse screening test); Other: Delayed Matching to Sample (DMS) test; Other: Spatial Working Memory (SWM) test; Other: Rapid Visual Information Processing (RVP) test; Other: Test for attentional performance (TAP) / Divided Attention; Other: Collection of saliva sample |
| Healthy volunteers, not cannabis/tobacco users | Other | Not described Receives: Other: Electroretinography; Other: Contrast sensitivity test during Electroencephalography; Other: Visual simultaneity test during Electroencephalography; Other: Face perception test during Electroencephalography; Other: Delayed Matching to Sample (DMS) test; Other: Spatial Working Memory (SWM) test; Other: Rapid Visual Information Processing (RVP) test; Other: Test for attentional performance (TAP) / Divided Attention; Other: Collection of saliva sample |
| Healthy volunteers, tobacco users | Other | Not described Receives: Other: Electroretinography; Other: Contrast sensitivity test during Electroencephalography; Other: Visual simultaneity test during Electroencephalography; Other: Face perception test during Electroencephalography; Other: Delayed Matching to Sample (DMS) test; Other: Spatial Working Memory (SWM) test; Other: Rapid Visual Information Processing (RVP) test; Other: Test for attentional performance (TAP) / Divided Attention; Other: Collection of saliva sample |
| Schizophrenia patients | Other | Not described Receives: Other: Electroretinography; Other: Contrast sensitivity test during Electroencephalography; Other: Visual simultaneity test during Electroencephalography; Other: Face perception test during Electroencephalography; Other: CAST (cannabis abuse screening test); Other: PANSS (Positive And Negative Symptoms Scale) test; Other: Delayed Matching to Sample (DMS) test; Other: Spatial Working Memory (SWM) test; Other: Rapid Visual Information Processing (RVP) test; Other: Test for attentional performance (TAP) / Divided Attention; Other: Collection of saliva sample |
What is being measured
The primary outcome is the main question the study is designed to answer.
Amplitude of P100 wave in contrast sensibility test
Measured: up to 1 month
Culmination time of the P100 wave in contrast sensibility test
Measured: up to 1 month
Secondary outcomes (10)
Amplitude of P100 wave in visual simultaneity test
Measured: up to 1 month
Culmination time of P100 wave in visual simultaneity test
Measured: up to 1 month
Amplitude of P100 wave in face perception test
Measured: up to 1 month
Amplitude of N170 wave in face perception test
Measured: up to 1 month
Culmination time of P100 wave in face perception test
Measured: up to 1 month
Culmination time of N170 wave in face perception test
Measured: up to 1 month
Amplitude of "a" wave in different ERG sequences
Measured: day 0
Amplitude of "b" wave in different ERG sequences
Measured: day 0
Culmination time of "a" wave in different ERG sequences
Measured: day 0
Culmination time of "b" wave in different ERG sequences
Measured: day 0
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Aug 2016 (estimated)
- Study startFeb 2014
- Primary completionJun 2019
- Study completionJun 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Cannabis UseStudies of the same condition, open and under way.
- More trials run by Central Hospital, Nancy, FranceThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 163 participants (actual)
Sponsor and investigators
- Lead sponsor
- Central Hospital, Nancy, France
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Vincent LAPREVOTE, Principal investigator, Maison des Addictions - CHU de Nancy, France
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02864680
- Sponsor's protocol ID
- 2013-A00097-38
- Acronym
- CAUSA MAP
- Status last verified
- Jun 2019
- First submitted
- 3 Aug 2016
- Last updated
- 29 Apr 2021
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- No
Publications
Remy I, Bernardin F, Ligier F, Krieg J, Maillard L, Schwan R, Schwitzer T, Laprevote V. Association between retinal and cortical visual electrophysiological impairments in schizophrenia. J Psychiatry Neurosci. 2023 May 19;48(3):E171-E178. doi: 10.1503/jpn.220224. Print 2023 May-Jun.
PubMed 37208126Bernardin F, Schwitzer T, Schwan R, Angioi-Duprez K, Ligier F, Bourion-Bedes S, Jansen C, Giersch A, Laprevote V. Altered central vision and amacrine cells dysfunction as marker of hypodopaminergic activity in treated patients with schizophrenia. Schizophr Res. 2022 Jan;239:134-141. doi: 10.1016/j.schres.2021.11.049. Epub 2021 Dec 7.
PubMed 34891077Remy I, Schwitzer T, Albuisson E, Schwan R, Krieg J, Bernardin F, Ligier F, Lalanne L, Maillard L, Laprevote V. Impaired P100 among regular cannabis users in response to magnocellular biased visual stimuli. Prog Neuropsychopharmacol Biol Psychiatry. 2022 Mar 8;113:110437. doi: 10.1016/j.pnpbp.2021.110437. Epub 2021 Sep 11.
PubMed 34520807
Study at a glance
From the registry record, last updated by the sponsor on 29 Apr 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Electrophysiological Study of the Functioning of Magnocellular Visual Pathway in Regular Cannabis Users
- ClinicalTrials.gov ID
- NCT02864680
- Acronym / sponsor ID
- CAUSA MAP / 2013-A00097-38
- Conditions
- Cannabis Use
- Keywords
- cannabis, magnocellular pathway
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 163 participants (actual)
- Lead sponsor
- Central Hospital, Nancy, FranceUniversity, hospital or other
- Study start
- Feb 2014 (actual)
- Primary completion
- Jun 2019 (actual)
- Study completion
- Jun 2019 (actual)
- First posted
- 12 Aug 2016 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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).
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Cannabis users | Other | Other: Electroretinography, Other: Contrast sensitivity test during Electroencephalography, Other: Visual simultaneity test during Electroencephalography, Other: Face perception test during Electroencephalography, Other: CAST (cannabis abuse screening test), Other: Delayed Matching to Sample (DMS) test, Other: Spatial Working Memory (SWM) test, Other: Rapid Visual Information Processing (RVP) test, Other: Test for attentional performance (TAP) / Divided Attention, Other: Collection of saliva sample |
| Healthy volunteers, not cannabis/tobacco users | Other | Other: Electroretinography, Other: Contrast sensitivity test during Electroencephalography, Other: Visual simultaneity test during Electroencephalography, Other: Face perception test during Electroencephalography, Other: Delayed Matching to Sample (DMS) test, Other: Spatial Working Memory (SWM) test, Other: Rapid Visual Information Processing (RVP) test, Other: Test for attentional performance (TAP) / Divided Attention, Other: Collection of saliva sample |
| Healthy volunteers, tobacco users | Other | Other: Electroretinography, Other: Contrast sensitivity test during Electroencephalography, Other: Visual simultaneity test during Electroencephalography, Other: Face perception test during Electroencephalography, Other: Delayed Matching to Sample (DMS) test, Other: Spatial Working Memory (SWM) test, Other: Rapid Visual Information Processing (RVP) test, Other: Test for attentional performance (TAP) / Divided Attention, Other: Collection of saliva sample |
| Schizophrenia patients | Other | Other: Electroretinography, Other: Contrast sensitivity test during Electroencephalography, Other: Visual simultaneity test during Electroencephalography, Other: Face perception test during Electroencephalography, Other: CAST (cannabis abuse screening test), Other: PANSS (Positive And Negative Symptoms Scale) test, Other: Delayed Matching to Sample (DMS) test, Other: Spatial Working Memory (SWM) test, Other: Rapid Visual Information Processing (RVP) test, Other: Test for attentional performance (TAP) / Divided Attention, Other: Collection of saliva sample |
Who may qualify
- Ages
- 18 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (17 listed)
- 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
Key exclusion criteria (15 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Electroretinography | Other | Cannabis users, Healthy volunteers, not cannabis/tobacco users, Healthy volunteers, tobacco users, Schizophrenia patients |
| Contrast sensitivity test during ElectroencephalographyStimuli 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. | Other | Cannabis users, Healthy volunteers, not cannabis/tobacco users, Healthy volunteers, tobacco users, Schizophrenia patients |
| Visual simultaneity test during ElectroencephalographyTwo 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. | Other | Cannabis users, Healthy volunteers, not cannabis/tobacco users, Healthy volunteers, tobacco users, Schizophrenia patients |
| Face perception test during ElectroencephalographyFaces 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. | Other | Cannabis users, Healthy volunteers, not cannabis/tobacco users, Healthy volunteers, tobacco users, Schizophrenia patients |
| CAST (cannabis abuse screening test) | Other | Cannabis users, Schizophrenia patients |
| PANSS (Positive And Negative Symptoms Scale) test | Other | Schizophrenia patients |
| Delayed Matching to Sample (DMS) test | Other | Cannabis users, Healthy volunteers, not cannabis/tobacco users, Healthy volunteers, tobacco users, Schizophrenia patients |
| Spatial Working Memory (SWM) test | Other | Cannabis users, Healthy volunteers, not cannabis/tobacco users, Healthy volunteers, tobacco users, Schizophrenia patients |
| Rapid Visual Information Processing (RVP) test | Other | Cannabis users, Healthy volunteers, not cannabis/tobacco users, Healthy volunteers, tobacco users, Schizophrenia patients |
| Test for attentional performance (TAP) / Divided Attention | Other | Cannabis users, Healthy volunteers, not cannabis/tobacco users, Healthy volunteers, tobacco users, Schizophrenia patients |
| Collection of saliva sampleIn case of specific consent of participant to ancillary study, for ancillary study | Other | Cannabis users, Healthy volunteers, not cannabis/tobacco users, Healthy volunteers, tobacco users, Schizophrenia patients |
Primary outcome
Amplitude of P100 wave in contrast sensibility test
Time frame: up to 1 month
Culmination time of the P100 wave in contrast sensibility test
Time frame: up to 1 month
10 secondary outcomes
Amplitude of P100 wave in visual simultaneity test
Time frame: up to 1 month
Culmination time of P100 wave in visual simultaneity test
Time frame: up to 1 month
Amplitude of P100 wave in face perception test
Time frame: up to 1 month
Amplitude of N170 wave in face perception test
Time frame: up to 1 month
Culmination time of P100 wave in face perception test
Time frame: up to 1 month
Culmination time of N170 wave in face perception test
Time frame: up to 1 month
Amplitude of "a" wave in different ERG sequences
Time frame: day 0
Amplitude of "b" wave in different ERG sequences
Time frame: day 0
Culmination time of "a" wave in different ERG sequences
Time frame: day 0
Culmination time of "b" wave in different ERG sequences
Time frame: day 0
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Apr 2021.
- Derived from this study: PubMed 37208126Remy I, Bernardin F, Ligier F, Krieg J, Maillard L, Schwan R, Schwitzer T, Laprevote V. Association between retinal and cortical visual electrophysiological impairments in schizophrenia. J Psychiatry Neurosci. 2023 May 19;48(3):E171-E178. doi: 10.1503/jpn.220224. Print 2023 May-Jun.
- Derived from this study: PubMed 34891077Bernardin F, Schwitzer T, Schwan R, Angioi-Duprez K, Ligier F, Bourion-Bedes S, Jansen C, Giersch A, Laprevote V. Altered central vision and amacrine cells dysfunction as marker of hypodopaminergic activity in treated patients with schizophrenia. Schizophr Res. 2022 Jan;239:134-141. doi: 10.1016/j.schres.2021.11.049. Epub 2021 Dec 7.
- Derived from this study: PubMed 34520807Remy I, Schwitzer T, Albuisson E, Schwan R, Krieg J, Bernardin F, Ligier F, Lalanne L, Maillard L, Laprevote V. Impaired P100 among regular cannabis users in response to magnocellular biased visual stimuli. Prog Neuropsychopharmacol Biol Psychiatry. 2022 Mar 8;113:110437. doi: 10.1016/j.pnpbp.2021.110437. Epub 2021 Sep 11.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Vincent LAPREVOTE principal investigator
Maison des Addictions - CHU de Nancy, France
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Electroretinography, Contrast sensitivity test during Electroencephalography and Visual simultaneity test during Electroencephalography in people with Cannabis Use, run by Central Hospital, Nancy, France at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 17 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 29 Apr 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Amplitude of P100 wave in contrast sensibility test (time frame: up to 1 month). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02864680, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Apr 2021.