%0 Journal Article
%T Striatal Hypodensities, Not White Matter Hypodensities on CT, Are Associated with Late-Onset Depression in Alzheimer's Disease
%A Jessica A. Brommelhoff
%A Bryan M. Spann
%A John L. Go
%A Wendy J. Mack
%A Margaret Gatz
%J Journal of Aging Research
%D 2011
%I Hindawi Publishing Corporation
%R 10.4061/2011/187219
%X This study examined whether there were neuroanatomical differences evident on CT scans of individuals with dementia who differed on depression history. Neuroanatomical variables consisted of visual ratings of frontal lobe deep white matter, subcortical white matter, and subcortical gray matter hypodensities in the CT scans of 182 individuals from the Study of Dementia in Swedish Twins who were diagnosed with dementia and had information on depression history. Compared to individuals with Alzheimer's disease and no depression, individuals with Alzheimer's disease and late-onset depression (first depressive episode at age 60 or over) had a greater number of striatal hypodensities (gray matter hypodensities in the caudate nucleus and lentiform nucleus). There were no significant differences in frontal lobe deep white matter or subcortical white matter. These findings suggest that late-onset depression may be a process that is distinct from the neurodegenerative changes caused by Alzheimer's disease. 1. Introduction While some studies have suggested that a history of depression is a risk factor for dementia later in life (e.g., [1, 2]), a number of authors have concluded that depression is an early symptom of dementia [3¨C6]. Boland [7] proposed that prodromal depression arises from dementia-related neuropathology. Several studies of nondemented older adults have suggested an association between white matter lesions and depression, specifically late-onset depression [8¨C14]. In a longitudinal study, white matter changes pre-dated and independently predicted the onset of depressive symptoms in older adult participants [15], providing some evidence that white matter changes are an antecedent to depression. Furthermore, in their review, Schweitzer et al. [16] concluded that the white matter changes that are common in individuals with late-onset depression were associated with cognitive impairment, and thus, were indicative of a prodrome to dementia. A greater amount of total brain white matter lesions has been associated with more severe depression or a greater number of depressive symptoms [9, 17, 18]. Other studies have suggested that white matter lesions in the frontal lobe are specifically associated with a higher rate of depressive symptoms among persons without dementia [8, 19]. A review of white matter lesions and clinical manifestations concluded that while periventricular white matter lesions are often associated with Alzheimer¡¯s disease (AD), lesions in the subcortical white matter are more often associated with late-onset depression [16]. Among 39
%U http://www.hindawi.com/journals/jar/2011/187219/