MRI High-Intensity Signals in Late-Life Depression and Alzheimer's Disease: A Comparison of Subjects Without Major Vascular Risk Factors

The authors examined periventricular white matter, deep white matter, and subcortical magnetic resonance imaging (MRI) high-intensity signals in subjects with late-life depression, probable Alzheimer's disease (DAT), and healthy, age-matched controls. All subjects were healthy and free of major vascular risk factors, including hypertension. MRIs were performed using a 1.5-tesla GE Signa scanner. T₂ and proton-density-weighted images were analyzed by a neuroradiologist blind to the clinical status of all subjects. There were no statistically significant differences on any of the MRI indices between the groups studied. These data demonstrate that late-life depression, like DAT, in the absence of major vascular risk factors, is not associated with a significant increase in MRI high-intensity signals when compared to healthy, control subjects.