Effect of Motivational Therapy on Schizophrenia With Cannabis Misuse (SCHIZOCAN)

An Open Multicentric Randomized Clinical Trial Assessing the Impact of Motivational Interviewing on Cannabis Consumption in Patients With Psychiatric Disease

Schizophrenia is a severe mental illness with a lifetime morbidity risk close to 1 %, involving both genetic and environmental risk factors. Prospective studies have shown that heavy use of cannabis in adolescence moderately increases the risk of developing schizophrenia. Many data have also suggested that the co-occurrence of cannabis abuse in patients with schizophrenia has a deleterious impact on the clinical outcome of schizophrenia. Cannabis abuse by schizophrenic patients is a significant public health problem for which there is no empirically validated treatment. We are presently studying the efficiency of motivational therapy on cannabis consumption in patients with schizophrenia.

Study Overview

• Status: Completed
• Conditions: Schizophrenia; Cannabis Dependence, Continuous
• Intervention / Treatment: Behavioral: Motivational therapy; Behavioral: Usual care

Detailed Description

Schizophrenia is a severe mental illness with a lifetime morbidity risk close to 1 %, involving both genetic and environmental risk factors. Prospective studies have shown that heavy use of cannabis in adolescence moderately increases the risk of developing schizophrenia. Many data have also suggested that the co-occurrence of cannabis abuse in patients with schizophrenia has a deleterious impact on the clinical outcome of schizophrenia. Cannabis abuse by schizophrenic patients is a significant public health problem for which there is no empirically validated treatment. We are presently studying the efficiency of motivational therapy on cannabis consumption in patients with schizophrenia.

330 patients with schizophrenia and cannabis abuse or dependence (according to DSM-IV criteria) are randomly assigned to 4 motivational interview during one month or usual intensive treatment. Treatment is conducted in outpatient which are evaluated at the inclusion and at 6 month with Time-Line Follow Bach for the consumption, PANSS score, number of relapse…). A outcome measure was urinalysis results providing an objective measure of cannabis use throughout the six month of the trial.

• Study Type: Interventional
• Enrollment (Actual): 97
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Colombes, France, 92700
    • Service de psychiatrie (Pr Adès)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

INCLUSION CRITERIA:

• Schizophrenia or schizo-affective disorder according to DSM-IV criteria
• Meeting DSM-IV criteria for actual cannabis abuse or dependance
• in current and regular contact with mental health service
• with an age at interview of 18 years or more
• No evidence of organic brain disease or clinically significant concurrent medical illness or learning disability
• Written informed consent was obtained from all subjects (patients and parents).

EXCLUSION CRITERIA:

• Not membership to a regime of social security or to a CMU

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Motivational Therapy; Four motivational interview for cannabis abuse in schizophrenia population during one month	Behavioral: Motivational therapy; One hour of motivational therapy each weak during 4 weeks
Other: Usual Care; Usual care with intensive psychotherapy	Behavioral: Usual care; Patients received at least six hour of usual therapy, as in the experimental group

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Cannabis consumption evaluated by the Time-Line Follow Back at 6 months with mean percentage of abstinent day	inclusion, 3 month, 6 month, 12 month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PANSS, GAF, number of DSM-IV criteria of cannabis dependence, May scale for treatment response, SF-12, la URICA, number of hospitalisation, mean number of joints per week, D9THC urinanalysis at 6M and cannabis consumption evaluated by the TLFB at 6M	PANSS : global, positive, negative, general scores	inclusion, 3 month, 6 month, 12 month. Only inclusion and 6 month for urianalysis

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris
• Investigators: Principal Investigator: Caroline DUBERTRET, MD,PhD, Assistance Publique - Hôpitaux de Paris

Study record dates

Study Major Dates

• Study Start: November 1, 2008
• Primary Completion (Actual): October 1, 2012
• Study Completion (Actual): April 1, 2013

Study Registration Dates

• First Submitted: September 30, 2008
• First Submitted That Met QC Criteria: November 24, 2008
• First Posted (Estimate): November 25, 2008

Study Record Updates

• Last Update Posted (Estimate): June 16, 2014
• Last Update Submitted That Met QC Criteria: June 13, 2014
• Last Verified: June 1, 2014

More Information

Terms related to this study

• Keywords: Schizophrenia; Motivational interview; Cannabis misuse comorbidity; Randomised open trial
• Additional Relevant MeSH Terms: Mental Disorders; Chemically-Induced Disorders; Substance-Related Disorders; Schizophrenia Spectrum and Other Psychotic Disorders; Schizophrenia; Marijuana Abuse
• Other Study ID Numbers: P 070156; AOM 07007 (Other Identifier: French Ministry)