Plasma catecholamine metabolites and early response to haloperidol.

Plasma homovanillic acid (HVA) and methoxyhydroxyphenyl glycol (MHPG) as well as serum haloperidol and prolactin were measured in patients admitted to a general hospital psychiatric service for treatment of acute psychosis. At 10 days, good responders compared to poor responders had higher mean plasma HVA values before and during the first week of treatment with 0.2-0.4 mg/kg haloperidol per day. MHPG values showed a similar pattern, although no significant differences were obtained between or within the two groups. Females predominated among good responders; neither DSM-III diagnoses nor steady state haloperidol levels differed significantly between the two groups. Significant correlations within some patients were obtained between prolactin and haloperidol (positive), prolactin and MHPG (negative), and HVA and MHPG (positive). Plasma catecholamine metabolites deserve further study as possible markers of early response to the treatment of acute psychosis with modest doses of neuroleptic drugs.