Comparing the efficacy of atypical antipsychotics in open uncontrolled versus double-blind controlled trials in schizophrenia

Abstract

Objective. Due to methodological reservations, open clinical trials investigating efficacy and tolerability of antipsychotic agents are often regarded with doubt. However, there are nearly no studies comparing findings of controlled double-blind with those of open trials. The aim of this study was to investigate whether results of open and double-blind approaches differ and thereby gain information about the validity of open trials.

Methods. After literature research, three atypical antipsychotic agents were identified for which at least three open and double-blind trials existed that met the inclusion criteria and from which either the reduction of the Brief Psychiatric Rating Scale (BPRS)- or Positive and Negative Symptom Scale (PANSS) scores or the response rate could be determined.

Results. There were no differences in the reduction of the BPRS- or PANSS scores or in the response rates for all three antipsychotic agents between open and double-blind trials.

Conclusions. Although double-blind controlled studies are essential in the investigation of new compounds, results of methodologically well-performed open studies are valid and deserve more attention. Preceding open trials may help in the design of double-blind studies.