Clinical trial NCT02864680: Electrophysiological Study of the Functioning of Magnocellular Visual Pathway in Regular Cannabis Users
Official title: Electrophysiological Study of the Functioning of Magnocellular Visual Pathway in Regular Cannabis Users
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Cannabis Use
Keywords: cannabis
magnocellular pathway
Lead sponsor: Central Hospital, Nancy, France
Sponsor class: OTHER
First posted: 2016-08-12
Enrollment: 163
Sex: ALL
Minimum age (years): 18
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

Brief 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).


Eligibility criteria: 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

Primary outcomes:
measure: Amplitude of P100 wave in contrast sensibility test
timeFrame: up to 1 month
measure: Culmination time of the P100 wave in contrast sensibility test
timeFrame: up to 1 month
Secondary outcomes:
measure: Amplitude of P100 wave in visual simultaneity test
timeFrame: up to 1 month
measure: Culmination time of P100 wave in visual simultaneity test
timeFrame: up to 1 month
measure: Amplitude of P100 wave in face perception test
timeFrame: up to 1 month
measure: Amplitude of N170 wave in face perception test
timeFrame: up to 1 month
measure: Culmination time of P100 wave in face perception test
timeFrame: up to 1 month
measure: Culmination time of N170 wave in face perception test
timeFrame: up to 1 month
measure: Amplitude of "a" wave in different ERG sequences
timeFrame: day 0
measure: Amplitude of "b" wave in different ERG sequences
timeFrame: day 0
measure: Culmination time of "a" wave in different ERG sequences
timeFrame: day 0
measure: Culmination time of "b" wave in different ERG sequences
timeFrame: day 0
Other outcomes:
measure: Relationship between variants of candidate genes for alterations of visual treatment and amplitude of P100 wave in contrast sensibility test
timeFrame: up to 3 years
Locations:
city: Nancy
country: France
facility: Maison des Addictions - CHU de Nancy, Hôpital St Julien
Study officials:
affiliation: Maison des Addictions - CHU de Nancy, France
name: Vincent LAPREVOTE
role: PRINCIPAL_INVESTIGATOR
References:
citation: Bernardin 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.
citation: Remy 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.