d-Amphetamine-induced heterogeneous changes in psychotic behavior in schizophrenia.

In this placebo-paired, double-blind study, 13 of 45 schizophrenic patients showed an acute improvement in schizophrenic symptoms following d-amphetamine infusion (20 mg). The 18 patients who worsened tended to have higher CSF 3-methoxy-4-hydroxyphenylglycol levels than did those who improved. d-Amphetamine blood levels and clinical descriptors of schizophrenic subgroups did not differentiate patients who improved from those who worsened; however, patients who improved had been significantly more psychotic before the infusion. Patients who worsened had been more psychotic than those who did not change. The authors suggest that those who did not change. The authors suggest that sensitivity to dopamine stimulation in schizophrenia is state-dependent rather than trait-dependent and that the simple, undirectional hypothesis of schizophrenia needs to be reformulated.