Background: Brain white matter changes (WMC) and depressive symptoms are linked, but the directionality of this association remains unclear.
Aims: To investigate the relationship between baseline and incident depression and progression of white matter changes.
Method: In a longitudinal multicentre pan-European study (Leukoaraiosis and Disability in the elderly, LADIS), participants aged over 64 underwent baseline magnetic resonance imaging (MRI) and clinical assessments. Repeat scans were obtained at 3 years. Depressive outcomes were assessed in terms of depressive episodes and the Geriatric Depression Scale (GDS). Progression of WMC was measured using the modified Rotterdam Progression scale.
Results: Progression of WMC was significantly associated with incident depression during year 3 of the study (P = 0.002) and remained significant after controlling for transition to disability, baseline WMC and baseline history of depression. There was no significant association between progression of WMC and GDS score, and no significant relationship between progression of WMC and history of depression at baseline.
Conclusions: Our results support the vascular depression hypothesis and implicate WMC as causal in the pathogenesis of late-life depression.