Haloperidol response and plasma catecholamines and their metabolites. 
Eleven acutely psychotic patients with schizophrenia or schizoaffective disorder underwent a 5-7 day drug-washout period (with lorazepam allowed) prior to participating in a 6-week controlled dose haloperidol trial.  Patients were evaluated longitudinally with clinical ratings and with plasma measures of the catecholamines dopamine (pDA) and norepinephrine (pNE) and their metabolites, homovanillic acid (pHVA) and 3-methoxy-4-hydroxyphenylglycol (pMHPG).  All patients exhibited clinical improvement with haloperidol; the decrease in their Brief Psychiatric Rating Scale (BPRS) scores ranged from 32 to 89%.  Measures of pHVA increased within the first week of treatment and returned to baseline by week 5.  The pattern of change of pDA resembled that of pHVA.  The pattern of change of pNE and pMHPG revealed a decrease over the course of treatment.  The early increase and the subsequent decrease in pHVA were strongly correlated with improvement in positive symptoms on the BPRS.  These data are consistent with previous reports on the change in pHVA and pMHPG during clinical response to haloperidol.  The data on change of pDA and pNE further describe the nature of the biochemical response to this drug.