Effect of risperidone on serum homocysteine levels in first-episode, drug-naive patients with schizophrenia

Some studies have shown that homocysteine (Hcy) levels are increased in patients with schizophrenia, and may be involved in its pathophysiology. The purpose of this study was to investigate the effect of the atypical antipsychotic drug risperidone on serum Hcy levels and to explore the relationship between the changes in Hcy levels and the therapeutic outcome, which, to our best knowledge have not been investigated. Fifty-six first-episode and drug-naive inpatients with schizophrenia were assigned to a 12-week treatment regime with risperidone. Clinical efficacy was determined with the Positive And Negative Syndrome Scale (PANSS). Serum Hcy levels were measured by sandwich enzyme-linked immunosorbent assay in schizophrenia patients before and after the 12-week treatment, and the values were compared with those of fifty-six age- and gender-matched healthy controls. Serum Hcy levels were significantly higher in first-episode and drug-naive patients than in control subjects (11.18 +/- 4.53 vs. 5.99 +/- 3.61 mu mol/L, F = 37.195, df =1, p = 1.73 x 10(-8)). Moreover, a significant positive correlation between Hcy levels and PANSS negative sub-score was observed (r = 0.515; p = 4.81 x 10(-8)). Serum Hcy levels were significantly decreased in patients after risperidone treatment (baseline: 11.18 +/- 4.53 mu mol/L vs. post-treatment: 8.98 +/- 4.07 mu mol/L, t = 3.857, p = 3.034 x 10(-4)). At post -treatment, there was a significant negative relationship between serum Hcy levels and PANSS negative sub -scores (r = 0.288, p = 0.032). High Hcy levels at the onset of psychosis suggests that it may contribute to the pathogenesis of schizophrenia and is related to clinical psychopathology. Serum Hcy levels were significantly decreased in schizophrenia patients after risperidone treatment. (C) 2017 Elsevier B.V. All rights reserved.