Diagnostic criteria and five-year outcome in schizophrenia. A report from the International Pilot Study of schizophrenia.

Systematic psychiatric assessment was undertaken on 131 patients (the American cohort of the International Pilot Study of Schizophrenia). Nine areas of outcome functioning were assessed five years later at follow-up evaluation on 63% of these patients. An analysis of 66 clinical and demographic variables established that the patients sucessfully followed-up were representatives of the entire cohort. Diagnostic data from initial evaluations and follow-up outcome assessment were used to examine the relationship between diagnostic criteria and outcome in schizophrenia. Applying the criteria for schizophrenic diagnosis defined by Langfeldt, by Schneider, and Carpenter et al failed to define a poor outcome group. No difference in outcome was found when traditional schizophrenic subtypes were contrasted. Overall outcome in 61 patients with conditions diagnosed as schizophrenic was heterogeneous. However, despite overlap, the mean outcome in the schizophrenic cohort was poorer than in the 19 nonschizophrenic patients.