Poor outcome has been considered by many psychiatrists as intrinsic to the concept of schizophrenia. A major issue has been whether a diagnostic concept of schizophrenia, based on symptoms alone, can identify patients who will have the poor outcome considered by many to be the validating criterion of "true" schizophrenia.
The strongest evidence that poor outcome schizophrenia can be identified by symptoms alone has come from studies using Langfeldt's symptom criteria of schizophrenia. The present investigation uses methodological controls not employed in earlier studies to evaluate the relationships between symptoms and outcome.
Results show that the symptom criteria of Langfeldt do not discriminate selectively a poor outcome category of schizophrenia. This challenges the major empirical basis for the view that symptom criteria alone can account for a poor outcome concept of this disorder.