An interventional study of Magnetoencephalograph (MEG) and Cambridge Neuropsychological Test Automated Battery (CANTAB). in Chronic Cannabis Users and Healthy Subjects, sponsored by Shalvata Mental Health Center. Status unknown at 1 site in Israel. Open to participants aged 20 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2012-01-02.
Sponsored by Shalvata Mental Health Center · Not applicable, Interventional, and Diagnostic
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
517 studies on the registry are indexed under Marijuana Abuse; 114 are open to participants now.
This study's planned enrollment of 115 is above the median of 60 across 421 interventional studies indexed under Marijuana Abuse.
Browse Marijuana Abuse studies →Shalvata Mental Health Center is the lead sponsor of 73 studies on the registry; 6 are open to participants now.
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Inclusion Criteria for both groups:
Inclusion Criteria for the control:
-Used cannabis maximum 50 times in their lives, and no more than once during the past year.
Inclusion Criteria for the experimental:
-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).
Exclusion Criteria for both groups:
(To prevent MEG artifacts by non relevant electric interference or brain conditions)
Procedure: Magnetoencephalograph (MEG) · Behavioral: Cambridge Neuropsychological Test Automated Battery (CANTAB). · Behavioral: Experimental: Scale for the Assessment of Negative Symptoms (SANS) and the Positive and Negative Syndrome Scale (PANSS)
Neurotypical subjects
Procedure: Magnetoencephalograph (MEG) · Behavioral: Cambridge Neuropsychological Test Automated Battery (CANTAB). · Behavioral: Experimental: Scale for the Assessment of Negative Symptoms (SANS) and the Positive and Negative Syndrome Scale (PANSS)
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
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)
Time frame: 30 min
Cognitive Measure
Cognitive Measure - All participants will be assessed for Cognitive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB).
Time frame: 1 hour
Electrophysiological Measure
Electrophysiological Measure- - All participants will be assessed for Electrophysiological assesment using the MEG (Magnetoencephalogram)
Time frame: 1 hour
This study is status unknown, as verified in Dec 2011. You cannot join it, but the record below documents what was studied.
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Shalvata Mental Health Center