Effect of apomorphine on schizophrenic symptoms.

The effects of apomorphine on psychotic symptoms were evaluated in chronic schizophrenic patients using double-blind placebo controlled procedures. Although on the basis of dopamine theory of schizophrenia, apomorphine was expected to increase schizophrenic symptoms, in this study apomorphine substantially reduced psychotic symptoms in some chronic schizophrenic patients. No patient showed the substantial increase in psychotic symptoms previously demonstrated after the administration of IV methylphenidate. These clinical effects of apomorphine in schizophrenia may be relevant to recent pharmacological research which has indicated that apomorphine also has potent effect on presynaptic dopamine neurons, in addition to its previously described postsynaptic receptor stimulation.