BRAIN MORPHOLOGY ASSESSED BY COMPUTED-TOMOGRAPHY IN PATIENTS WITH GERIATRIC DEPRESSION, PATIENTS WITH DEGENERATIVE DEMENTIA, AND NORMAL CONTROL SUBJECTS

To determine whether patients with geriatric depression have specific alterations in brain morphology, internal (ventricles) and external (frontal, temporal, and parieto-occipital) components of the cerebrospinal fluid (CSF) spaces were examined. Planimetric measurements of computed tomographic (CT) scans from patients with geriatric depression were compared with measurements from two age- and sex-matched control groups: normal control subjects and patients with primary degenerative dementia. Scans of 34 patients (6 men, 28 women; mean age 70.7 years) who met DSM-III-R diagnostic criteria for major depression, 29 patients with DSM-III-R primary degenerative dementia (8 men, 21 women; mean age 71.2 years), and 43 nonpsychiatric control subjects (10 men, 33 women; mean age 70.8 years) were evaluated. The areas of the frontal and parieto-occipital sulci, the Sylvian fissures, and the lateral and third ventricles were measured separately for the right and left hemispheres. Compared with the control subjects, patients with geriatric depression revealed a remarkable enlargement (up to 125%) of the left Sylvian fissure on several levels and a more subtle enlargement of the ventricles, cortical sulci, and right Sylvian fissure (20-50%). The laterality index differed significantly between depressed patients and normal control subjects (but not between the demented patients and the normal control group) only for the Sylvian fissure. Demented patients showed a considerable brain atrophy that affected all CSF components (enlargment of 30-160%), but the left temporal region was less affected than in the depressed patients. Compared with the findings in geriatric depression, ventricular enlargement was significant in dementia. In the group with geriatric depression, there was no correlation between CT parameters and disease duration, The findings provide further evidence of alterations in brain morphology of patients with geriatric depression. The pattern of pathomorphology differs from that of demented patients.