Clinical trial NCT00798109: Effect of Motivational Therapy on Schizophrenia With Cannabis Misuse
Official title: An Open Multicentric Randomized Clinical Trial Assessing the Impact of Motivational Interviewing on Cannabis Consumption in Patients With Psychiatric Disease
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Schizophrenia
Cannabis Dependence, Continuous
Keywords: Schizophrenia
Cannabis misuse comorbidity
Motivational interview
Randomised open trial
Lead sponsor: Assistance Publique - Hôpitaux de Paris
Sponsor class: OTHER
First posted: 2008-11-25
Enrollment: 97
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: 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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Cannabis consumption evaluated by the Time-Line Follow Back at 6 months with mean percentage of abstinent day
timeFrame: inclusion, 3 month, 6 month, 12 month
Secondary outcomes:
measure: 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
timeFrame: inclusion, 3 month, 6 month, 12 month. Only inclusion and 6 month for urianalysis
Other outcomes:
Locations:
city: Colombes
country: France
facility: Service de psychiatrie (Pr Adès)
Study officials:
affiliation: Assistance Publique - Hôpitaux de Paris
name: Caroline DUBERTRET, MD,PhD
role: PRINCIPAL_INVESTIGATOR
References: