title: Topiramate add-on in treatment-resistant schizophrenia: a randomized, double-blind, placebo-controlled, crossover trial.
abstract: OBJECTIVE
  We tested the hypothesis that topiramate is more effective than placebo in reducing symptoms in patients with treatment-resistant schizophrenia when combined with ongoing antipsychotic medication.
  
  
  METHODS
  Twenty-six hospitalized treatment-resistant patients with chronic DSM-IV-diagnosed schizophrenia participated in a randomized, double-blind, placebo-controlled trial in which 300 mg/day of topiramate was gradually added to their ongoing treatment (clozapine, olanzapine, risperidone, or quetiapine) over two 12-week crossover treatment periods. Data were collected from April 2003 to November 2003.
  
  
  RESULTS
  In intention-to-treat analysis, topiramate was more effective than placebo in reducing Positive and Negative Syndrome Scale general psychopathologic symptoms (effect size = 0.7, p = .021), whereas no significant improvement was observed in positive or negative symptoms.
  
  
  CONCLUSIONS
  Glutamate antagonist topiramate may be an effective adjuvant treatment in reducing general psychopathologic symptoms in patients with schizophrenia resistant to treatment with second-generation antipsychotics.
authors.affiliation: Department of Forensic Psychiatry, University of Kuopio, Niuvanniemi Hospital, Kuopio, Finland. jari.tiihonen@niuva.fi
authors.forename: Jari
authors.initials: J
authors.lastname: Tiihonen
authors.forename: Pirjo
authors.initials: P
authors.lastname: Halonen
authors.forename: Kristian
authors.initials: K
authors.lastname: Wahlbeck
authors.forename: Eila
authors.initials: E
authors.lastname: Repo-Tiihonen
authors.forename: Soile
authors.initials: S
authors.lastname: Hyvärinen
authors.forename: Markku
authors.initials: M
authors.lastname: Eronen
authors.forename: Hanna
authors.initials: H
authors.lastname: Putkonen
authors.forename: Pirjo
authors.initials: P
authors.lastname: Takala
authors.forename: Olli-Pekka
authors.initials: OP
authors.lastname: Mehtonen
authors.forename: Martin
authors.initials: M
authors.lastname: Puck
authors.forename: Jorma
authors.initials: J
authors.lastname: Oksanen
authors.forename: Pasi
authors.initials: P
authors.lastname: Koskelainen
authors.forename: Grigori
authors.initials: G
authors.lastname: Joffe
authors.forename: Juhani
authors.initials: J
authors.lastname: Aer
authors.forename: Tero
authors.initials: T
authors.lastname: Hallikainen
authors.forename: Olli-Pekka
authors.initials: OP
authors.lastname: Ryynänen
authors.forename: Erkki
authors.initials: E
authors.lastname: Tupala
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use*; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005632:Fructose / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D000077236:Topiramate; D016896:Treatment Outcome
chemical_list: D000927:Anticonvulsants; D014150:Antipsychotic Agents; D010919:Placebos; D000077236:Topiramate; D005632:Fructose