In a double-blind, placebo-controlled trial of treatment with the neuroleptic pimozide, negative symptoms improved in schizophrenic patients who showed an antipsychotic response. Furthermore, there was a significant positive correlation between changes in positive and negative symptoms for the group as a whole, including both pimozide responders and nonresponders. In our patient sample, neuroleptic treatment did not exert a differential effect on the positive and negative symptoms of schizophrenia. It is conceivable that negative symptoms are state dependent and may become neuroleptic nonresponsive over time just as positive symptoms do in some chronic patients.