Lateralized neuropsychological dysfunction in affective disorder and schizophrenia.

The authors compared the cognitive functioning of 22 schizophrenic patients, 105 patients with affective disorder, and 99 age-matched normal control subjects. Results of an aphasia screening test indicated that the schizophrenic patients made more total errors and more dominant temporal/temporoparietal errors than patients with affective disorders and that patients in both groups made more errors than controls. Patient sex, age, drug treatment received at test time, previous neuroleptic drug treatment, and severity of illness did not account for the differences. These findings support the validity of the authors' diagnostic research criteria and confirm prior reports of differences in dominant hemisphere dysfunction between schizophrenic patients and patients with affective disease.