Comparative studies of thought disorders. II. Schizoaffective disorder.

We examined thought disorder in 22 patients with schizoaffective disorder (12 schizoaffective-manic and ten schizoaffective-depressed) using Research Diagnostic Criteria. The Thought Disorder Index was used to tag 22 categories of thought disorder that ranged from mild to severe. Qualitative patterns in the thought disorder of schizoaffective patients were compared with those of 20 manic and 43 schizophrenic patients. Manic and schizoaffective-manic patients produced a high number of combinatory responses, but those produced by the schizoaffective-manic patients lacked the humor and playfulness of those of the manics. The schizoaffective-manic patients, like the schizophrenic patients, produced a high number of responses in the categories of idiosyncratic verbalizations, autistic thinking, and confusion. Unlike the manic patients, schizoaffective-depressed patients generally produced a few absurd and idiosyncratic responses in a setting of constricted output. The data strongly suggest that the thinking disorders of schizoaffective patients are like those of the schizophrenic patients.