Temporal lobe measurement in primary affective disorder by magnetic resonance imaging.

Magnetic resonance imaging brain scans were performed on 17 patients with primary affective disorder and 21 normal subjects. A coronal slice through the temporal lobes at the level of the pons and interpeduncular cistern was selected in each subject, and specific temporal lobe structures and the cerebral area were measured. Ratios between structures of the same hemisphere were calculated. The ratio of the temporal lobe to cerebral area was smaller in patients than controls both on the left (p less than .02) and on the right (p less than .03). The data suggest that patients with primary affective disorder may have a relative decrease in the size of the temporal lobe compared with normal controls.