Psychopathology and the electroencephalogram.

We investigated the relationship between EEG abnormalities and clinical psychopathological features in a consecutive sample of 159 patients who satisfied our research criteria for schizophrenia or affective disorder and in whom an EEG was obtained. In the 44 patients with abnormal EEGs, we found significant correlations between left-sided EEG abnormality and the clinical features of formal thought-disorder and emotional blunting, correlations which were independent of the variance associated with age, sex, past or present drug administration, or research diagnosis. The correlation for formal thought-disorder was specifically related to the left temporal lobe, a finding which we discuss in terms of the similarity between formal thought-disorder defined as a language dysfunction and fluent posterior aphasia. Because of the small sample size these results, although statistically significant, should be interpreted with caution and require confirmation by other workers.