ABSTRACT
OBJECTIVES: The authors investigated the possibility of homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) concentrations in plasma to be biological markers before and after the pharmacological treatment of schizophrenia. METHODS: Twenty-six patients with schizophrenia were enrolled after two week washout of neuroleptics. Baseline sampling was done after washout. Consequent samplings were done at two and four week time-points after neuroleptic treatment. The concentrations of HVA and MHPG were analysed with clinical variables, such as age, age of onset, duration of illness, period of hospitalization, and changes of clinical state. The HVA and MHPG were assayed using high pressure liquid chromatographyelectrochemical detection method. RESULTS: A significant association was observed between the age of onset and plasma HVA concentration in washout state of antipsychotics. The earlier onset group had lower plasma HVA concentration than the late onset group. A significant association was observed between the age of onset and plasma MHPG concentration in washout state of antipsychotics. The earlier onset group had lower plasma MHPG concentration than the late onset group. CONCLUSIONS: The present findings suggest that the activities of dopamine and norepinephrine are different with respect to age of onset in the neuroleptic-naive schizophrenia. Plasma HVA and MHPG concentration can be biological markers for the subgrouping of schizophrenia.