Chronic Cannabis Users: A Model for Negative Symptoms in Schizophrenia
Clinical Assessment of Negative Symptoms Neurocognitive and Electrophysiological Characteristics in Chronic Cannabis Users
1 other identifier
interventional
115
1 country
1
Brief Summary
The aim of the current study is set out to find a human model for negative symptoms based on clinical observation that chronic cannabis users express negative symptoms and characterize by the same neurocognitive and electrophysiology characteristics like patient suffer from schizophrenia. Towards that end the first part of the study is set out to explore weather chronic cannabis user's express negative symptoms similar to patient suffer from schizophrenia. The second part of the study will explore the neurocognitive and electrophysiology characteristics of those cannabis users that express negative symptoms. This data will be compared to parallel data of schizophrenia patients with predominantly negative symptom. Several lines of biological and genetic evidence support the cannabinoid hypothesis for schizophrenia. Particularly, it is most significant clinically that the possible involvement of the cannabinoid system in the neural basis for the negative symptoms. This hypothesis based on clinical findings that chronic cannabis use causes a combination of symptoms including apathy, avolition, lack of interest, passivity, and cognitive impairments, the so-called "amotivational syndrome," which resembles the core negative symptoms of schizophrenia in behavioral level as well as the brain level. Both are associated with the functions or integrity of the frontal lobe due to its role in creating self-directed behaviors, deficits in which may underlie alogia, anhedonia, and flat affect. Despite the aforementioned similarities, to date, there is no documentation for such a relationship. Recognition that chronic cannabis users share the same or similar constellation of symptoms and similar neurocognitive and electrophysiology characteristics could provide a key to develop a human model for negative symptoms and an essential tool to comprehensive understanding of the etiology of negative symptoms and development of an innovative therapy. The investigators Hypothesize That Chronic Cannabis Users Would Express the Same Constellation of Behaviors as Negative Symptoms of Schizophrenia; as well as similar neurocognitive and electrophysiology characteristics
Trial Health
Trial Health Score
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participants targeted
Target at P50-P75 for not_applicable
1 active site
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Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
June 23, 2011
CompletedFirst Posted
Study publicly available on registry
June 27, 2011
CompletedStudy Start
First participant enrolled
July 1, 2011
CompletedPrimary Completion
Last participant's last visit for primary outcome
July 1, 2012
CompletedJanuary 2, 2012
December 1, 2011
1 year
June 23, 2011
December 29, 2011
Conditions
Keywords
Outcome Measures
Primary Outcomes (3)
Clinical Measure
All participants will be assessed for negative symptoms using the Scale for the Assessment of Negative Symptoms (SANS) and the Positive and Negative Syndrome Scale (PANSS)
30 min
Cognitive Measure
Cognitive Measure - All participants will be assessed for Cognitive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB).
1 hour
Electrophysiological Measure
Electrophysiological Measure- - All participants will be assessed for Electrophysiological assesment using the MEG (Magnetoencephalogram)
1 hour
Study Arms (2)
Chronic Cannabis Users
EXPERIMENTALControl
EXPERIMENTALNeurotypical subjects
Interventions
Brain imaging device that records the magnetic fields in the brain.
the CANTAB is sensitive to cognitive changes caused by a wide range of Central Nervous System disorders and medication side-effects . The CANTAB uses a computer with a touch screen, and affords a rapid and non-invasive assessment of cognitive functions.
The SANS and PANSS scales asses the presence and severity of Positive and Negative of Schizophrenia
Eligibility Criteria
You may qualify if:
- Healthy men and women
- Ages 20-65
- Give informed consent for participation in the study.
- Used cannabis maximum 50 times in their lives, and no more than once during the past year.
- Use of cannabis for at least 2 years and in the last 6 months for at least 4 days a week.
- (-After minimum 12 hours of abstinence (in order to eliminate acute cannabis effects, minimize the withdrawal effect while retaining neurophysiological effects from altered CB1 activity).
You may not qualify if:
- (To prevent MEG artifacts by non relevant electric interference or brain conditions)
- History of epilepsy, seizure, or hot spasm, sever head injuries.
- History of metal in the head (outside the mouth space).
- History of surgery including metal implant or history of metal particles in the eye, pacemaker, or any other medical pump.
- History of migraines.
- History of drug or alcohol abuse during the last year. Inability to achieve satisfying level of communication with the subject Control Group (healthy Subjects)
- History of psychiatric diagnosis
- Drug or alcohol addiction in the year prior to the study
- History of epilepsy, seizure, or hot spasm.
- History of head injuries.
- History of metal in the head (outside the mouth space).
- History of surgery including metal implant or history of metal particles in the eye, pacemaker, or any other medical pump.
- History of migraines.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
Bar-Ilan University
Givat Shmuel, Israel
MeSH Terms
Interventions
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Hilik Levkovitz, prof.
shalvata MHC
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- NON RANDOMIZED
- Masking
- NONE
- Purpose
- DIAGNOSTIC
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
June 23, 2011
First Posted
June 27, 2011
Study Start
July 1, 2011
Primary Completion
July 1, 2012
Last Updated
January 2, 2012
Record last verified: 2011-12