Epidemiology of MRI-defined vascular depression: A longitudinal, community-based study in Korean elders.

Background: There are no cross-sectional or longitudinal epidemiological studies present on MRI-defined vascular depression in community populations. The purpose of this study was to estimate the prevalence rates of both vascular and non-vascular late life depression (LLD) at baseline, to examine the natural course of LLD, and to investigate the influence of White matter hyperintensities (WMHs) on depression after three years.

Method: The baseline study employed a two-stage design, Phase I population survey (n=783) and Phase II diagnostic evaluation (n=122). In the 3-year follow-up study, baseline participants completing the second phase were reassessed with the same methodology. WMHs severity was rated visually by the modified Fazekas scale and WMHs volume was calculated using an automated method.

Results: The prevalence rates of vascular major depressive disorder (MDD) and vascular non-major depressive disorder (nMDD) were 2.39% (56.2% of MDD) and 4.24% (34.0% of nMDD). Subjects with a score of 2 or more on the modified Fazekas scale in either deep white matter hyperintensities or subcortical gray matter ratings had an 8.1 times greater risk of developing a depressive disorder in the 3-year follow-up study. Greater Log WMHs volume (odds ratio=5.78, 95% CI, 1.04-31.72) at baseline was an independent predictor for depressive disorder in the 3-year assessment.

Limitations: Response rate and follow-up rate were relatively low.

Conclusions: Vascular depression is common and makes up about a half of MDD in elders. Greater WMHs severity is a crucial factor predicting future depression risk, which supports the previous vascular depression hypothesis.