Response to neuroleptic drugs as a device for classifying schizophrenia.

Although schizophrenic patients are routinely treated with neuroleptic medication, the diversity in response to such treatment is noteworthy; some patients are exquisitely responsive to neuroleptic treatment, while others are clearly resistant. The authors examine the hypothesis that neuroleptic-responsive and neuroleptic-resistant patients have different illnesses by considering the following issues: the reliability of the distinction between neuroleptic responsiveness and resistance; the consistency in neuroleptic responsiveness over time; the association between neuroleptic responsiveness and other clinical features; and the neuroleptics' therapeutic action. On the basis of the data available and on theoretical and historical grounds, the distinction between neuroleptic-responsive and neuroleptic-resistant patients warrants application in both clinical and research settings.