Schizophrenia Daily News Blog

Topiramate add-on in treatment-resistant schizophrenia

Cross-over trial of topiramate add-on for treatment-resistant schizophrenia

A new study on Topiramate suggests:

* Topiramate 300 mg/day improves general but not positive/negative psychotic symptoms

* Topiramate could have value for ameliorating depressive symptoms

The results of a cross-over trial published in the Journal of Clinical Psychiatry confirmed the hypothesis that topiramate may be an effective adjuvant treatment for those with treatment-resistant schizophrenia. In this randomized, double-blind trial, topiramate showed significant advantage over placebo in reducing general psychotic symptoms, although no significant improvement was seen in positive or negative symptoms.

The study authors note that the greatest reductions with topiramate vs. placebo were observed in the general psychopathologic symptoms of depression (PANSS item G6), preoccupation (item G15) and guilt feelings (G3). They suggest that the therapeutic effect of topiramate may differ from that of lamotrigine, which has shown benefits for both positive and general psychopathologic symptoms in schizophrenia (Tiihonen, 2003 & Kremer, 2004).

The authors conclude, "Although pharmacologic studies generally focus on the change in positive and negative symptoms, it has been observed that depressive symptoms ... contribute more to the quality of life of schizophrenic patients ... Therefore, topiramate add-on treatment may improve the quality of life in a sub-group of chronically seriously ill patients suffering from general psychopathologic symptoms such as depression." Due to the limitation of a small sample size, the authors add that their results must be considered preliminary.

The Study was funded by non-industry sources.

Tiihonen J, Halonen P, Wahlbeck K, et al.: Topiramate add-on in treatment-resistant schizophrenia: a randomized, double-blind, placebo-controlled crossover trial. J Clin Psychiatry 2005; 66(8): 1012-1015