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Dual Diagnosis (Psychosis and Cannabismisuse): Comparison of Specialized Treatment Versus Unspecified Treatment

This study has been completed.
Information provided by:
University of Konstanz Identifier:
First received: October 30, 2008
Last updated: January 11, 2010
Last verified: October 2008

Intention of the study is to examine, if the symptomatology of dual diagnosis patients is less severe after a special indication training for reduction of cannabis consumption in comparison to unspecified trainings.

Point of interest is psychopathology and consumerism.

Condition Intervention Phase
Psychotic Disorders Marijuana Abuse Intervention Behavioral: Cannabis-Consumption-Reduction-Training Behavioral: Social competence Training Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Dual Diagnosis Psychosis and Substance Abuse: Short- and Middle-term Changes in Symptomatology After Visiting a Group Education Programme to Reduce Consumption of Cannabis

Resource links provided by NLM:

Further study details as provided by University of Konstanz:

Primary Outcome Measures:
  • PANSS Positive and Negative Symptom Scale [ Time Frame: post intervention, six months follow-up ]

Secondary Outcome Measures:
  • Urinstatus for cannabinoids [ Time Frame: weekly during and post intervention, follow-up ]

Estimated Enrollment: 50
Study Start Date: January 2006
Study Completion Date: January 2010
Primary Completion Date: June 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: ACT
Behavioral: Cannabis-Consumption-Reduction-Training
8 sessions within 4 weeks (twice a week, 45 minutes each) Cognitive behavioral therapy with focus on cannabis abuse
Active Comparator: CG
Control group
Behavioral: Social competence Training
8 sessions within 4 weeks (twice a week, 45 minutes) training to develop and ameliorate social competences

Detailed Description:

Dual diagnosis patients (psychosis and cannabis abuse) account for more clinical admissions than single diagnosis patients.

Cannabis misuse is a known risk factor for recurrence of psychosis.

A specified intervention on the basis of a manual for schizophrenic substance abusers is administered to inpatients in a specialized unit for young schizophrenic patients in a psychiatric hospital.

The control group, same indication (psychotic disorder and cannabis misuse) receives social competence training (specified for schizophrenic patients as well).

Admission to groups is randomly.


Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Clinical diagnosis of schizophrenia and disorders with psychotic features
  • Misuse of cannabis during 12 months preceding admission to hospital

Exclusion Criteria:

  • Not able to attend training twice a week for 45 minutes (concentration, attention, psychotic symptoms, agitation)
  • Discharge from hospital before completion of training
  Contacts and Locations
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Please refer to this study by its identifier: NCT00783185

University of Konstanz
Konstanz, Baden-Württemberg, Germany, 78462
Sponsors and Collaborators
University of Konstanz
Principal Investigator: Hans Watzl, Dr. University of Konstanz
  More Information

Responsible Party: Hans Watzl, Dr., University of Konstanz Identifier: NCT00783185     History of Changes
Other Study ID Numbers: CRET
Study First Received: October 30, 2008
Last Updated: January 11, 2010

Keywords provided by University of Konstanz:
psychotic disorders

Additional relevant MeSH terms:
Mental Disorders
Psychotic Disorders
Marijuana Abuse
Schizophrenia Spectrum and Other Psychotic Disorders
Substance-Related Disorders
Chemically-Induced Disorders processed this record on August 18, 2017