Changes in urinary monoamine metabolites with antipsychotic treatment in schizophrenia

Objective: Monoamine neurotransmitters have been considered important mediators of schizophrenia pathology and antipsychotic drug action. This study examines the level of monoamine metabolites, homovanillic acid (HVA), 5-hydroxy indole acetic acid (5-HIAA), and vanillylmandelic acid (VMA), monoamine metabolites of major neurotransmitters dopamine, serotonin and norepinephrine, respectively in urine of patients with schizophrenia as compared to normal controls and the change in monoamine metabolites with antipsychotic treatment. Methods: Thirty-four drug-free patients with schizophrenia diagnosed with Diagnostic and Statistical Manual of Mental Disorders Fourth Edition criteria and 15 normal controls were taken for the study. Patients were assessed for psychopathology using positive and negative syndrome scale (PANSS) scale at baseline and 4 weeks after the treatment. Urinary monoamine metabolites (HVA, 5-HIAA, and VMA) were measured before and after 4 weeks of treatment using high-performance liquid chromatography. Results: There was a trend toward higher levels of HVA and VMA in the patients as compared to controls. There was a trend toward reduction in 5-HIAA levels with treatment in patients with schizophrenia. No correlation was found between the levels of monoamine metabolites and psychopathology. Significant positive correlation was found between 5-HIAA with VMA and HVA. Conclusion: The present study indicates that noninvasive measurement of monoamine metabolites in urine may be of value in differentiating patients with schizophrenia from controls.