Antidepressant Controlled Trial for Negative Symptoms in Schizophrenia

Inclusion Criteria: * An OPCRIT (Operational Criteria Checklist for Psychosis: 57) diagnosis of schizophrenia, schizophreniform, schizoaffective disorder or psychosis NOS as defined by DSM-IV. * A negative subscale score of 20 or more on the Positive and Negative Syndrome Scale for Schizophrenia (PANSS). At least three of the seven items on the negative symptom subscale should be rated 3 or more. * Age 18-75 years, inclusive * Clinically stable for the last 3 months with a consistent antipsychotic regimen. * Competent and willing to provide written, informed consent. Exclusion criteria: * Any medical contraindications to an SSRI antidepressant. * Currently receiving antidepressant or clinician wants to treat with an antidepressant; * Taking any medications that risk interacting with citalopram * Known congenital long QT syndrome, congestive heart failure, bradyarrhythmias * QT limit above the upper limit of normal as determined by an electrocardiogram (ECG) * Serum potassium and/or magnesium levels below the lower limits of normal * Currently fulfil criteria for major depressive disorder; alcohol/substance hazardous use or dependence in past 3 months * Treated with ECT in the last 8 weeks. * Pregnant or planning to become pregnant * Cognitive or language difficulties that would preclude subjects providing informed consent or compromise participation in study procedures. * Lack of consent, as judged by the patient's psychiatrist