add-on topiramate for the pharmacological management of schizophrenia: a double blind randomized clinical trial

objective: glutamate antagonists including anticonvulsant topiramate have been recommended for the pharmacological management of schizophrenia. methods: a randomized, double-blind, placebo controlled clinical trial was performed on 32 patients diagnosed with schizophrenia (18-45 years old). baseline information was gathered on demographic characteristics, vital signs, height, weight, smoking habit, (past) psychiatric history, drug history and adverse effects to medication. patients were randomly assigned to topiramate group (n=16) or placebo one (n=16). positive and negative syndrome scale (panss) was administered on each patient at baseline, on days 28 and 56. results: the mean total panss score in topiramate group was 96.87 (85.37-108.37) at baseline, 85.68 (74.67-96.70) on day 28 and 76.87(66.06-87.69) on day 56. these were 101.87 (90.37-113.37), 100.31 (89.29-111.32) and 100.56 (89.74-111.37) respectively in placebo group. general linear model for repeated measure analysis showed that topiramate has lowered panss score significantly. conclusion: significant decline was also found in all three panss components (negative, positive and psychopathology symptoms). topiramate can therefore be used as an effective add-on medication in treating schizophrenia.