Effects of warm-supplementing kidney yang (WSKY) capsule added on risperidone on cognition in chronic schizophrenic patients: a randomized, double-blind, placebo-controlled, multi-center clinical trial

Objective To evaluate the effects of warm-supplementing kidney yang (WSKY) capsule added on risperidone on cognition in chronic schizophrenic patients. Methods A randomized, double-blind, placebo-controlled, multi-center clinical trial was conducted. All 200 patients who met the DSM-IV diagnostic criteria for schizophrenia were randomly assigned to double-blind treatment with WSKY capsule (n = 100) or placebo (n = 100) added on risperidone for 8 weeks. The primary outcome measure was the cognitive function assessment assessed by the classic form of the Wisconsin Card Sorting Test (WCST) at baseline and week 8. The secondary outcome measures were assessed including the positive and negative symptoms scale (PANSS), the social disability screening schedule (SDSS), and the Hamilton rating scale for depression (HAM-D-17) at baseline, week 2, week 4, and week 1, The extrapyramidal side effects were assessed each week using the abnormal involuntary movement scale (AIMS) and rating scale for extrapyramidal side effects (RSESE), while adverse events were assessed using treatment emergent symptoms scale (TESS) as additional indicators of tolerability throughout the trial. Results The response rates of the WSKY group for the number of completed categories (CC), errors responses number (ER). perseveringly errors responses number (PER), and conceptual level (CL) of WCST assessment were significantly higher than those of placebo. The reduction in the SDSS score from baseline to endpoint was significantly greater in the WSKY group than those in the placebo. There were no significant differences in the response rates for the correct responses number, perseveringly responses number (PR) of WCST between the treatment groups. The improvements in the WCST indexes, PANSS score, HAM-D-17 score were no significant differences from baseline to endpoint between the two groups at week 8. There were no significant differences in AIMS, RSESE, and TESS compared patients treated with WSKY capsule with those in placebo during treatment. Conclusion WSKY capsule added on risperidone may improve cognitive function, social function of the chronic schizophrenic patients, and the WSKY safely during treatment. Copyright (C) 2008 John Wiley & Sons, Ltd.