Cerebral microvascular dysfunction may contribute to depression via disruption of brain structures involved in mood regulation, but evidence is limited. We investigated the association of retinal microvascular function, a proxy for microvascular function in the brain, with incidence and trajectories of clinically relevant depressive symptoms.

Longitudinal data are from The Maastricht Study of 5952 participants (59.9 ± 8.5 years/49.7% women) without clinically relevant depressive symptoms at baseline (2010–2017). Central retinal arteriolar equivalent and central retinal venular equivalent (CRAE and CRVE) and a composite score of flicker light-induced retinal arteriolar and venular dilation were assessed at baseline. We assessed incidence and trajectories of clinically relevant depressive symptoms (9-item Patient Health Questionnaire score ⩾10). Trajectories included continuously low prevalence (low, n = 5225 [87.8%]); early increasing, then chronic high prevalence (early-chronic, n = 157 [2.6%]); low, then increasing prevalence (late-increasing, n = 247 [4.2%]); and remitting prevalence (remitting, n = 323 [5.4%]).

After a median follow-up of 7.0 years (range 1.0–11.0), 806 (13.5%) individuals had incident clinically relevant depressive symptoms. After full adjustment, a larger CRAE and CRVE were each associated with a lower risk of clinically relevant depressive symptoms (hazard ratios [HRs] per standard deviation [s.d.]: 0.89 [95% confidence interval (CI) 0.83–0.96] and 0.93 [0.86–0.99], respectively), while a lower flicker light-induced retinal dilation was associated with a higher risk of clinically relevant depressive symptoms (HR per s.d.: 1.10 [1.01–1.20]). Compared to the low trajectory, a larger CRAE was associated with lower odds of belonging to the early-chronic trajectory (OR: 0.83 [0.69–0.99]) and a lower flicker light-induced retinal dilation was associated with higher odds of belonging to the remitting trajectory (OR: 1.23 [1.07–1.43]).

These findings support the hypothesis that cerebral microvascular dysfunction contributes to the development of depressive symptoms.

Cumulative burden from vascular risk factors (VRFs) has been associated with an increased risk of depressive symptoms in mid- and later life. It has been hypothesised that this association arises because VRFs disconnect fronto-subcortical white matter tracts involved in mood regulation, which puts older adults at higher risk of developing depressive symptoms. However, evidence for the hypothesis that disconnection of white matter tracts underlies the association between VRF burden and depressive symptoms from longitudinal studies is scarce.

This preregistered study analysed longitudinal data from 6,964 middle-aged and older adults from the UK Biobank who participated in consecutive assessments of VRFs, brain imaging, and depressive symptoms. Using mediation modelling, we directly tested to what extend white matter microstructure mediates the longitudinal association between VRF burden and depressive symptoms.

VRF burden showed a small association with depressive symptoms at follow-up. However, there was no evidence that fractional anisotropy (FA) of white matter tracts mediated this association. Additional analyses also yielded no mediating effects using alternative operationalisations of VRF burden, mean diffusivity (MD) of single tracts, or overall average of tract-based white matter microstructure (global FA, global MD, white matter hyperintensity volume).

Our results lend no support to the hypothesis that disconnection of white matter tracts underlies the association between VRF burden and depressive symptoms, while highlighting the relevance of using longitudinal data to directly test pathways linking vascular and mental health.

Age-related vascular changes have long been documented as an etiopathogenic factor of some geriatric depressive syndromes. More recently, it has emerged the concept of “Vascular Depression” recognizing that cardiovascular disease may predispose, precipitate or perpetuate late life depression. This condition was defined by an episode of major depressive disorder within the preceding 12 months in elderly with cardiovascular/cerebrovascular disease, or major cardiovascular risk factors. Vascular Depression isn`t described in DSM-V, and that difficults clinical recognition and affects clinically informed systematic studies.

Regarding a clinical case, we enphasize the clinical impact of Vascular Depression`s hypothesis.

We present a qualitative review of this topic using the Pubmed Central database.

74 years old male patient, with major depressive disorder about ten years. Depressive and cognitive symptoms didn`t respond to antidepressive treatment and his functional state has gradually declined.

Vascular depression develops after the 60 – 65 years in the absence of personal and family history of affective disorder. The key symptoms are low energy, anhedonia, deficits in selfinitiation, psychomotor retardation, reduced processing speed and lack of insight into mood symptoms. Clinical assessment includes a review of history of vascular risk factors or/and disease, but also an imagiological evidence demonstrating subcortical white matter abnormalities. Insidious and chronic course tends to delay its recognition and management. This becomes critical because Vascular Depression is associated with poor response to antidepressant treatment and persistent depressive symptoms. It`s also associated with poor selfmanagement of comorbidities and impairment in daily function. Increased mortality from all causes is widely documented.