Plasma asymmetric dimethylarginine (ADMA) concentrations in patients with first and multiple episode schizophrenia.

An increasing number of reports in the literature indicate that asymmetric dimethylarginine (ADMA) regulates nitric oxide generation in numerous disease states. ADMA has been less studied in psychiatric disorders. The purpose of this study was to determine plasma ADMA concentrations in patients with schizophrenia compared to healthy controls. The study was conducted in 49 male patients with schizophrenia and 30 healthy male control subjects. The patient group was 24 first episode and 25 multiple episode schizophrenia participants. All schizophrenic patients were administered the Scale for the Assessment of Negative Symptoms, the Scale for the Assessment of Positive Symptoms (SAPS) and the Brief Psychiatric Rating Scale. Measurement of plasma concentrations of ADMA was accomplished by HPLC. There was a significant increase in the plasma ADMA concentrations in patients with schizophrenia when compared to healthy controls. There were no significant correlations between the plasma concentrations of ADMA and scores of psychiatric rating scales. In the multiple episode schizophrenia subgroup, the mean plasma ADMA concentration was significantly higher than in the first episode schizophrenia subgroup. The study indicate that plasma ADMA concentrations in patients with schizophrenia are elevated.