Computed tomographic scans in patients with schizophrenia, schizoaffective, and bipolar affective disorder.

Computed tomographic (CT) scans of 28 chronic schizophrenic patients, 15 chronic schizoaffective patients, and 19 patients with bipolar affective disorder were compared on three measures: ventricular size, sulcal prominence (cortical atrophy), and cerebellar atrophy. Because the patients with bipolar disorder were older, measures were adjusted by controlling for age statistically or excluding patients over age 50 years. After age correction, there were no significant differences across diagnostic groups. Each group contained some subjects with enlarged ventricles, sulcal prominence, and/or cerebellar atrophy. The similarity of CT scan results across the three groups argues against ascribing these abnormalities to any one psychiatric disorder or to a specific drug effect. Sampling effects and the possibility of differential causes of the findings in the different diagnostic groups must be considered. Examination of the correlations of these three CT scan measures found them to be significantly related to each other. Age correlated with all measures when patients over age 50 years were included in the analysis, but not for patients aged 50 years and younger.