Abnormal auditory brain-stem responses in hallucinating schizophrenic patients

Abnormal auditory brain-stem responses (ABRs) were recorded in 10 out of 20 schizophrenic in-patients. The response abnormalities did not show any correlation to the degree of psychopathology, sub-group of schizophrenia, age, sex, or cerebral ventricular enlargement. Nor was there any correlation to previous neuroleptic treatment: a pathological ABR was recorded in 5 of the 8 patients who had never received such medication. A statistically significant relationship was found between ABR pathology and auditory hallucinations: 9 of the 11 patients who admitted having hallucinations exhibited brain-stem response abnormality, whereas ABR abnormality was recorded in only 1 of the 9 patients who denied having hallucinations. The data imply that brain-stem dysfunction is involved in the psychopathology of schizophrenia, and that interference with the auditory pathways in the brain-stem may induce auditory hallucinations in schizophrenic patients.