Is the clinical expression of late-life depression influenced by brain changes? MRI subcortical neuroanatomical correlates of depressive symptoms.
Résumé
BACKGROUND: "Vascular depression" has recently been proposed. It is characterized by magnetic resonance imaging (MRI) T2-weighted subcortical lesions, a late onset of first episode of depression, and reduced heritability; a cerebrovascular etiology is suggested. The validity of "vascular depression" might be strengthened if an association was found between the subcortical lesions used to define it and particular depressive symptoms. METHODS: A blinded cross-sectional examination of DSM-III-R depressive symptoms (American Psychiatric Association, 1987) and MRI T2-weighted subcortical lesions in 44 patients with late-life depression. RESULTS: Many associations were found; however, because of multiple comparisons, their significance is viewed with caution. The most robust finding was that psychomotor retardation was independently related to total white-matter score. The odds of showing psychomotor retardation was increased 1.9 times for every point increase in severity of white-matter change. CONCLUSION: In late-life depression the clinical expression of the depression is influenced by the pattern of MRI T2-weighted subcortical lesions. This gives some validity to the concept of an MRI-defined "vascular" subtype of late-life depression and strengthens the argument for including neuroimaging in the classification of late-life depression.