The purpose of this study is to examine the short - term effects of clozapine on alcohol use in persons with schizophrenia and an alcohol use disorder. The hypothesis is that clozapine will have greater efficacy in reducing alcohol use than other antipsychotic medications.

Inclusion Criteria:

• Diagnosis of schizophrenia or schizoaffective disorder
• Current diagnosis of an alcohol use disorder with active use in the last 30 days.
• The participant (or the participant's authorized legal representative) understands the nature of the study and has he/she signed an informed consent.
• Ages 19-65.
• Taking olanzapine, risperidone, quetiapine or a typical antipsychotic agent for at least 8 weeks prior to study randomization
• If taking depot medication, at least 3 injection cycles since the last injection prior to study randomization.

Exclusion Criteria:

• Contraindication to clozapine
• Women who are currently pregnant or who desire to become pregnant during the course of the study.
• Current and past treatment with clozapine
• Current treatment with agents proposed to curtail substance use (e.g., disulfiram, naltrexone, acamprosate, buspirone) and agents contraindicated for use with clozapine (e.g., inderal, tegretol, lithium).
• Meets DSM-IV criteria for current dependence of substances other than alcohol.