Chronic Cannabis Users: A Model for Negative Symptoms in Schizophrenia

NCT ID: NCT01382433

Last Updated: 2012-01-02

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

UNKNOWN

Clinical Phase

NA

Total Enrollment

115 participants

Study Classification

INTERVENTIONAL

Study Start Date

2011-07-31

Brief Summary

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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

Detailed Description

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Conditions

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Chronic Cannabis Users Healthy Subjects

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

DIAGNOSTIC

Blinding Strategy

NONE

Study Groups

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Chronic Cannabis Users

Group Type EXPERIMENTAL

Magnetoencephalograph (MEG)

Intervention Type PROCEDURE

Brain imaging device that records the magnetic fields in the brain.

Cambridge Neuropsychological Test Automated Battery (CANTAB).

Intervention Type BEHAVIORAL

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.

Experimental: Scale for the Assessment of Negative Symptoms (SANS) and the Positive and Negative Syndrome Scale (PANSS)

Intervention Type BEHAVIORAL

The SANS and PANSS scales asses the presence and severity of Positive and Negative of Schizophrenia

Control

Neurotypical subjects

Group Type EXPERIMENTAL

Magnetoencephalograph (MEG)

Intervention Type PROCEDURE

Brain imaging device that records the magnetic fields in the brain.

Cambridge Neuropsychological Test Automated Battery (CANTAB).

Intervention Type BEHAVIORAL

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.

Experimental: Scale for the Assessment of Negative Symptoms (SANS) and the Positive and Negative Syndrome Scale (PANSS)

Intervention Type BEHAVIORAL

The SANS and PANSS scales asses the presence and severity of Positive and Negative of Schizophrenia

Interventions

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Magnetoencephalograph (MEG)

Brain imaging device that records the magnetic fields in the brain.

Intervention Type PROCEDURE

Cambridge Neuropsychological Test Automated Battery (CANTAB).

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.

Intervention Type BEHAVIORAL

Experimental: Scale for the Assessment of Negative Symptoms (SANS) and the Positive and Negative Syndrome Scale (PANSS)

The SANS and PANSS scales asses the presence and severity of Positive and Negative of Schizophrenia

Intervention Type BEHAVIORAL

Eligibility Criteria

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Inclusion Criteria

1. Healthy men and women
2. Ages 20-65
3. 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).

Exclusion Criteria

(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.
Minimum Eligible Age

20 Years

Maximum Eligible Age

65 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Shalvata Mental Health Center

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Hilik Levkovitz, prof.

Role: PRINCIPAL_INVESTIGATOR

shalvata MHC

Locations

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Bar-Ilan University

Givat Shmuel, , Israel

Site Status RECRUITING

Countries

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Israel

Central Contacts

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keren yefet

Role: CONTACT

052-8812960

Facility Contacts

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keren yefet, PHD

Role: primary

052-8812960

Other Identifiers

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0010-11-SHA

Identifier Type: -

Identifier Source: org_study_id

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