Clozapine for Cannabis Use Disorder in Schizophrenia (CLOCS)

Investigator: Philip Harvey

Institutional Protocol #: 20120940

National Clinical Trials Identifier: NCT01639872

Funding Agency/Sponsor: Intramural

Division: Psychiatry

Therapeutic Area: Other

Phase: Phase IV

Enrolling Sites: University of Miami Medical Group, University of Miami Hospital & Clinics

Enrolling Since: 10/16/2017


Many individuals with schizophrenia also suffer from marijuana addiction that worsens their
problems related to schizophrenia. Most of the medications prescribed for schizophrenia have
no effect on reducing marijuana use. Preliminary data suggests that clozapine, an atypical
antipsychotic, may limit marijuana use in people diagnosed with schizophrenia, but it is not
commonly used due to its side effects and is reserved for people who do not respond to other
antipsychotic medications.

In the proposed study, 132 individuals who are diagnosed with both schizophrenia and a
cannabis use disorder will be randomized to a 12-week treatment course with either clozapine
or risperidone (another commonly prescribed antipsychotic medication) to test the hypothesis
that patient treated with clozapine will have decreased cannabis use as compared to patients
treated with risperidone.

Should this study indicate that clozapine will lessen marijuana use in persons diagnosed with
schizophrenia more than risperidone, it will provide evidence needed to begin to shift
clinical practice toward its use in this population.

Eligibility Criteria:

Inclusion Criteria:

- Clinical diagnosis of schizophrenia

- Clinical diagnosis of a cannabis use disorder (abuse or dependence)

Exclusion Criteria:

- Pregnant,trying to become pregnant or nursing

- History of a seizure disorder

- Current treatment with clozapine or risperidone

- Contraindication to treatment with clozapine or risperidone

Gender: All

Minimum Age: 18 Years

Maximum Age: 55 Years

Accepts healthy volunteers: No

Please note that this is written for scientific review, and if there are any questions or clarifications needed, please contact

Tania Guardia, Sr. Program Coordinator
(305) 243 7067


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