Primary objective: To assess the efficacy of adding raloxifene as an adjunct to antipsychotic treatment to improve negative symptoms of schizophrenia in postmenopausal women.

This is a double-blind, randomized, placebo-controlled study of raloxifene as adjuvant treatment to antipsychotic treatment. Treatment period of 12 weeks.

The primary result obtained is that women treated with 60 mg of raloxifene compared to those treated with a placebo show greater improvement in psychotic symptoms. The investigators also found improved response in some aspects of social functioning and neuropsychological functioning.

Inclusion Criteria:

• Diagnosis of schizophrenia (DSM-IV criteria)
• Postmenopausal patients. Postmenopause is defined as after a period of one year of spontaneous amenorrhea and a serum follicle stimulating hormone (FSH) level > 20IU/L.
• Stable doses of their current antipsychotic medication for at least a month prior to study initiation.
• Presence of significant negative symptoms (defined as one or more negative symptom score greater than 4 in the PANSS scale) (Kay 1987)
• Patients have to give written informed consent to participate in the study.

Exclusion Criteria:

• Patients with a substance abuse/dependence diagnosis in the previous six months.
• Mental retardation.
• Endocrine abnormalities, acute or chronic liver disease, impaired kidney function.
• History of thromboembolism, breast cancer, abnormal uterine bleeding, history of cerebrovascular accident.
• Patients taking hormone replacement therapy.
• Patients taking mood stabilizer medication that cannot be discontinued.