The efficacy of raloxifene versus placebo was compared over a six-month period, as an adjuvant treatment of the negative symptoms of schizophrenia in a group of 80 post-menopausal women. The aim of the study is to analyze whether raloxifene has an effect on the positive and negative symptoms of schizophrenia, and on psychopathological symptoms in general, and on social and neuropsychological functioning, and to study the influence of genetic polymorphisms in treatment response.