Plasma catecholamine metabolites in schizophrenics: evidence for the two-subtype concept.

Abstract Plasma homovanillic acid (pHVA) and plasma methoxyhydroxyphenyl glycol (pMHPG), as well as plasma haloperidol, were measured in 33 schizophrenic patients before and during 6 weeks of haloperidol treatment. Good responders had higher baseline pHVA values compared with poor responders (17.4 ± 8.8 ng/ml, n = 22 versus 11.4 ± 5.0 ng/ml, n = 11, p n = 13) and poor ( n = 9) responders, and pMHPG showed no change during treatmnt in poor responders. Significant correlations between baseline pHVA and pMHPG values were found in 22 patients. Good responders and poor responders did not differ significantly in terms of age, duration of illness, severity of presenting symptoms, haloperidol dose, or plasma drug concentration. Two hypothetical subtypes of schizophrenia and both dopamine and norepinephrine systems involved in schizophrenic psychopathology are proposed.