The consistency of thought disorder in mania and schizophrenia. An assessment of acute psychotics.

This report presents an assessment of 20 manic and 20 schizophrenic patients using a clinical rating instrument: the Scale for Assessment of Thought, Language, and Communication (TLC). These 40 patients were assessed three times within a 10-day period at the outset of an acute psychotic episode with open-ended interviews which were then evaluated with the TLC. It was found that clinically rated speech disorders were relatively consistent within these patients at the outset of a psychotic episode. Furthermore, it was found that composite ratings of positive and negative speech disorders, as defined by the TLC, were stable discriminators of the manic and schizophrenic patients, while global thought disorder was not useful as a discriminator. The results provide evidence that thought disorder in psychosis may be a stable trait of patients during acute episodes and that positive and negative disorder is a useful construct.