White matter lesions as a predictor of depression in the elderly:: The 3C-Dijon study

Background: There is increasing evidence for a link between cerebrovascular disease and depression in the elderly but the mechanisms are still unknown. This study examines the longitudinal relationship between depression and white matter lesions (WML) in a sample of elderly aged 65 years and older. Methods: Three City (3C)-Dijon is a 4-year follow-up population-based prospective study of 1658 subjects. At baseline, lifetime major depressive episode diagnosis was established using the Mini International Neuropsychiatric Interview. At each study wave, severity of depressive symptoms was assessed using Center for Epidemiological Studies-Depression (CES-D), and antidepressants intake was recorded. At baseline, lifetime major depression (LIVID) was defined as lifetime major depressive episode or antidepressant medication intake. At follow-up, subjects were classified "incident depression" if scoring high at CES-D or antidepressant users. At baseline, cerebral magnetic resonance imaging (MRI) was performed to quantify WML volumes using an automated method of detection. At 4-year follow-up, 1214 subjects had a second MRI. Results: Cross-sectional analysis showed a significantly higher WML volume in subjects with LIVID compared with other subjects. Adjusted longitudinal analysis showed that increase in WML load was significantly higher in subjects with baseline LIVID (2.1 cm(3) VS. 1.5 cm(3), p = .004). Among subjects free of depression up to baseline (n = 956), the higher the baseline WML volume, the higher the risk of developing depression during follow-up (odds ratio one quartile increase: 1.3; 95% confidence interval: = 1.1-1.7). Conclusions: Our data show that depression and WML volumes are strongly related. These results are consistent with the hypothesis of a vascular depression in the elderly.