Impact of dopamine supersensitivity psychosis in treatment-resistant schizophrenia: An analysis of multi-factors predicting long-term prognosis.

Background: Although a variety of factors are known to be significantly related to poor prognosis in schizophrenia, their interactions remain unclear. Dopamine supersensitivity psychosis (DSP) is a clinical concept related to long-term pharmacotherapy and could be one of the key factors contributing to the development of treatment-resistant schizophrenia (TRS). The present study aims to explore the effect of DSP on progression to TRS. Methods: Two-hundreds and sixty-five patients were classified into either a TRS or Non-TRS group based on retrospective survey and direct interview. The key factors related to prognosis, including the presence or absence of DSP episodes, were extracted, and each factor was compared between the two groups. Results: All parameters except for the duration of untreated psychosis (DUP) were significantly worse in the TRS group compared to the Non-TRS group. In particular, the TRS group presented with a significantly higher rate of DSP episodes than the Non-TRS group. Regression analysis supported the notion that DSP plays a pivotal role in the development of TRS. In addition, deficit syndrome was suggested to be a diagnostic subcategory of TRS. Conclusions: Our data confirmed that the key predicting factors of poor prognosis which have been established would actually affect somehow the development of TRS. In addition, the occurrence of a DSP episode during pharmacotherapy was shown to promote treatment refractoriness. (c) 2016 Elsevier B.V. All rights reserved.