Comparison of schizophrenic patients with formal thought disorder and neurologically impaired patients with aphasia.

This study compares the speech and language of 14 schizophrenic patients having a formal thought disorder with 13 neurologically impaired patients with aphasia. Transcribed interviews with these patients were blindly assessed by five specialists for classification as schizophrenic or aphasic. Three of the five specialists performed better than chance but only one achieved high discriminating ability. Interrater reliability was poor. Five of 14 language abnormalities assessed differentiated the diagnostic groups. These findings suggest that schizophrenic patients share many language abnormalities with aphasic patients but do not exhibit a classic aphasic syndrome.