Brain monoamine oxidase activity in schizophrenics and controls.

Postmortem samples of caudate nucleus and frontal cortex from schizophrenic, schizophrenic-like, and control subjects were examined for monoamine oxidase activity using dopamine, phenylethylamine, and 5-hydroxytryptamine as substrates. There were no significant differences between the diagnostic groups with any of the three substrates. Neither was there a difference between the sexes, nor a consistent relationship of enzyme activity to age.