Serum thiobarbituric acid-reactive substances and free thiol levels in schizophrenia patients: Effects of antipsychotic drugs

This study investigated the levels of serum thiobarbituric acid-reactive substances (TBARS) and free thiols in schizophrenia patients and healthy control subjects, and evaluated the effects of antipsychotic drugs. During a 2-year period, 77 schizophrenia patients and 110 healthy control subjects were recruited. Psychiatric diagnoses of schizophrenia were made according to DSM-IV criteria. Serum TBARS and free thiol levels were measured using the standard procedure in the laboratory room. Using analysis of covariance with body mass index adjustment, we found that schizophrenia patients had significantly lower serum levels of free thiols than the controls. Fifty-five patients were followed up and their serum TBARS and free thiol levels were measured at the end of the 4-week treatment with antipsychotic drugs. We found that there were significantly decreased changes in free thiol levels, but not in TBARS levels. Furthermore, patients taking risperidone had significantly decreased changes in free thiol levels. Additionally, the responders showed significantly decreased changes in free thiol levels, but not in TBARS levels. In conclusion, these analytical results suggested that serum free thiols might play an important role in the psychopathology of schizophrenia and could be used as markers for determining the treatment response in schizophrenia.