Decrease in dopamine, its metabolites and noradrenaline in cerebrospinal fluid of schizophrenic patients after withdrawal of long-term neuroleptic treatment.

Dopamine (DA), homovanillic acid (HVA), dihydroxyphenylacetic acid (DOPAC), noradrenaline (NA), and 5-hydroxyindolacetic acid (5HIAA) were measured in cerebrospinal fluid (CSF) of 15 chronic schizophrenic patients before and 2 weeks after withdrawal of long-term neuroleptic treatment. Total neuroleptic-like activity in serum (NLA) was determined at the same times. Levels of DA and its metabolites (DOPAC and HVA) and NA were significantly reduced after the discontinuation of neuroleptic treatment. No change was observed in 5HIAA values. NLA was substantially reduced, but still remained detectable. The decrease in DA, DOPAC, and HVA all showed positive correlations with each other, and correlated negatively with NLA measured after 2 weeks. Our data implies that the decrease in DA turnover is the result of the discontinuance of DA receptor blockade, while the change in NA level is independent of it.