Apomorphine response and subtyping of schizophrenia.

(1) We conducted a double-blind study of acute effects of low-dose apomorphine (0.01 mg/kg) in 12 chronic schizophrenic patients. (2) Overall, there was no significant difference in therapeutic response to apomorphine versus placebo. (3) Of the individual subscales of the Brief Psychiatric Rating Scale, anxiety and depression syndromes showed significant improvement with apomorphine. (4) On dividing the schizophrenic patients into two groups on the basis of computed tomography (CT) scans, it was found that there was a significant difference in their responsiveness to apomorphine. (5) Patients with abnormal CT scans (primarily, large ventricles) tended to have improvement or no change with apomorphine, whereas those with normal CT scans tended to have worsening of symptoms. (6) Possible implications of our findings are discussed.