To determine if neuroleptic treatment changes the natural course of schizophrenia, 22 studies were reviewed in which relatively similar patients were or were not given neuroleptics at specific times during the course of their illness. Nineteen of the studies were from first- or predominantly first-break populations. While there was little consensus among the authors of the studies reviewed, a reanalysis of the data indicates that early intervention with neuroleptics in first-break schizophrenic patients increases the likelihood of an improved long-term course. This finding is similar to that of earlier investigators who indicated there was a decrease in patients with the more severe forms of the illness following the introduction of convulsive therapies. Furthermore, there is evidence that stable schizophrenic patients whose neuroleptics are discontinued and have relapses may have a difficult time returning to their previous level of function. The findings describe in this paper have implications for both the treatment of schizophrenia and for understanding the pathophysiological processes that determine the course of the disorder.