A randomized, double-blind, placebo-controlled trial of fluvoxamine in patients with schizophrenia: a preliminary study. 
Cognitive impairments in schizophrenia are associated with suboptimal psychosocial performance.  Several lines of evidence have suggested that endoplasmic reticulum protein sigma-1 receptors were involved in cognitive impairments in patients with schizophrenia and that the sigma-1 receptor agonist fluvoxamine was effective in treating cognitive impairments in animal models of schizophrenia and in some patients with schizophrenia.  A randomized, double-blind, placebo-controlled, parallel trial of fluvoxamine adjunctive therapy in patients with schizophrenia was performed.  A total of 48 patients with chronic schizophrenia were enrolled.  Subjects were randomly assigned to an 8-week administration of add-on fluvoxamine (n = 24, titrated up to 150 mg/d) or placebo (n =24) in a total 12-week double-blind trial.  The primary outcome measure was the Cambridge Neuropsychological Test Automated Battery (CANTAB), assessing visual memory, working memory, attention, and executive function.  The secondary outcome measures were the Positive and Negative Syndrome Scale, the Scale for the Assessment of Negative Symptoms, the Quality of Life Scale, and the Montgomery-Åsberg Depression Rating Scale.  Fluvoxamine was well tolerated.  No significant time × group interaction effects were observed in the scores of the CANTAB, Positive and Negative Syndrome Scale, Scale for the Assessment of Negative Symptoms, Quality of Life Scale, or the Montgomery-Åsberg Depression Rating Scale.  However, in secondary analyses, the change from baseline to end point on the Spatial Working Memory strategy score (executive function) of CANTAB improved in the fluvoxamine group.  This study suggests no major benefit of fluvoxamine adjunctive therapy to improve cognitive impairments in patients with schizophrenia.  Nevertheless, a further study using a large sample size will be needed to confirm the secondary analyses findings.