The novel oxidative stress marker thioredoxin is increased in first-episode schizophrenic patients

Schizophr Res. 2009 Sep;113(2-3):151-7. doi: 10.1016/j.schres.2009.05.016. Epub 2009 Jun 21.


Excessive free radical production leading to oxidative stress may be involved in the pathophysiology of schizophrenia. Oxidative stress increases serum thioredoxin (TRX), a redox-regulating protein with antioxidant activity recognized as an oxidative-stress marker. The aim of this study was to assess the clinical significance of serum TRX levels in various stages of schizophrenia. Serum TRX levels were determined using ELISA from 60 never-medicated first-episode and 66 medicated chronic schizophrenia patients and 66 healthy control subjects matched for age and gender. The psychopathology of schizophrenia was assessed by the Positive and Negative Syndrome Scale (PANSS). Our results showed that group comparison between first-episode and chronic patients and control groups revealed significantly increased serum TRX only in first-episode patients. Increased levels of TRX in patients experiencing an acute stage schizophrenic episode was also significantly higher compared to chronic schizophrenic patients on antipsychotic medication. Serum TRX was also positively correlated with positive symptoms of schizophrenia. Our results suggest oxidative stress occurs in an acute stage of schizophrenic episode and may have an important role in pathogenesis and symptomology of schizophrenia. Lower TRX levels in chronic patients treated with antipsychotics may have implications for treatment outcome.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Analysis of Variance
  • Biomarkers / blood
  • Chi-Square Distribution
  • Enzyme-Linked Immunosorbent Assay / methods
  • Female
  • Humans
  • Male
  • Middle Aged
  • Oxidative Stress / physiology*
  • Psychiatric Status Rating Scales
  • Schizophrenia / blood*
  • Schizophrenia / physiopathology*
  • Severity of Illness Index
  • Thioredoxins / blood*
  • Young Adult


  • Biomarkers
  • Thioredoxins