In Alzheimer's disease (AD), the relationship between white-matter changes on magnetic resonance images and behavior are unclear. Therefore, magnetic resonance images, cognition, and psychiatric state were assessed in patients with AD with depression (AD/DEP; n = 18) and without depression (AD; n = 45), older depressed patients (n = 12) and older normal individuals (n = 25). High-intensity signals in the cortex and subcortical regions were similar in number and proportions among all groups, even when hypertensive patients were excluded. No correlations to cognitive or psychiatric state were found. Periventricular signals were categorized using a 1- (absent) to 6- (thick, irregular caps and stripes) point scale. The categories were similar among groups except that patients with AD exhibited more category 5 changes than did normal subjects, neuropsychological performance was significantly worse in patients with AD who had category 5 and 6 changes when compared to those in category 1. These results suggest that periventricular changes may predict poor neuropsychological performance in patients with AD. However, neither deep white-matter lesions nor periventricular changes are useful for diagnostic purposes. © 1991, American Medical Association. All rights reserved.