The validity of vascular depression as a diagnostic construct

Abstract

The 'vascular depression' (VaD) construct initially proposed a relationship between late-life depression (LLD) and vascular disease and stimulated significant investigation into this nature of this relationship. The construct became synonymous with an aetiological proposition that vascular disease or risk factors are central in the pathogenesis of LLD. Validity of the VaD construct warrants consideration. This chapter reviews strategies that have been used to demonstrate an aetiological relationship between vascular disease and depression and considers the evidence for this association from various perspectives including (i) clinical features and the specificity of a VaD clinical phenotype, (ii) neuroimaging findings, (iii) proposed mechanisms for the aetiological role of vascular disease in depression, (iv) prognostic implications with a focus on treatment response and (v) shared pathomechanisms underlying both depression and vascular pathology. Our review suggests that the evidence in support of a causal relationship between depression and vascular disease, and thus the validity of the VaD construct, is not consistent. Whilst strong associations exist, the agnostic ascription of vascular disease as causative in LLD is potentially misleading, particularly in light of emerging evidence for diverse and interrelated pathomechanisms.