Increments in plasma homovanillic acid concentrations after neuroleptic discontinuation are associated with worsening of schizophrenic symptoms

Biogenic amine metabolites in plasma of drug-naive schizophrenic patients: associations with symptomatology

The main metabolites of dopamine, noradrenaline, and serotonin, homovanillic acid, methoxyhydroxyphenylglycol (MHPG), and 5-hydroxyindoleacetic acid (5-HIAA), were estimated in plasma of 20 drug-naive young male schizophrenic patients and 21 healthy controls. Although there were no significant differences between the two groups, multiple regression analysis revealed strong associations of the patients' 5-HIAA and MHPG plasma levels to their scores in the Brief Psychiatric Rating Scale items. 5-HIAA levels were mainly related positively to hostility and negatively to somatic concern, and MHPG positively to disorientation and negatively to emotional withdrawal and uncooperativeness. The results suggest that levels of the neurotransmitter metabolites may be related to certain psychological dysfunctions of the patients rather than to disease entities.